CN109241629B - Method for determining axial pressure stable bearing capacity of upright column of dust remover box body - Google Patents

Method for determining axial pressure stable bearing capacity of upright column of dust remover box body Download PDF

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CN109241629B
CN109241629B CN201811048730.3A CN201811048730A CN109241629B CN 109241629 B CN109241629 B CN 109241629B CN 201811048730 A CN201811048730 A CN 201811048730A CN 109241629 B CN109241629 B CN 109241629B
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column
wall
upright post
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wallboard
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王登峰
杨诗晴
徐雯凌
邢凯丽
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Jiangnan University
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Abstract

The invention discloses a method for determining the axial pressure stable bearing capacity of a vertical column of a dust remover box body, belonging to the technical field of dust remover structures. The applicable dust remover box structure characteristics do: the wallboard is the steel sheet of putting more energy into, and the box stand is rolling H shaped steel, and the stand has the transverse bracing of perpendicular to wallboard direction to provide the restraint. Through a large number of finite element numerical calculations, the influence of the initial geometric defects and welding defects of the structure and the stressed skin effect exerted by the wallboard are fully considered, and a stability coefficient expression of the dust collector box body axis compression column represented by the geometric parameters of the multi-item structure is summarized and formulated, so that the stable bearing capacity calculation method is provided on the basis. The method has the advantages of wide application range, convenient use and higher reliability, and can be used for reference of dust remover design and production units.

Description

Method for determining axial pressure stable bearing capacity of upright column of dust remover box body
Technical Field
The invention relates to a method for determining the axial pressure stable bearing capacity of a vertical column of a dust remover box body, belonging to the technical field of dust remover structures.
Background
The dust remover is an important environment-friendly device which is widely applied to industries such as electric power, metallurgy, chemical industry, building materials and the like and is used for eliminating smoke dust. The capture and collection of the smoke dust particles are completed in the box body of the dust remover, so the box body is the most important process part in the supporting equipment of the dust remover, the enclosure structure of the box body generally adopts a wallboard-upright column structure system, and the structural form and the load condition are complex. The top of the box body is provided with a supporting beam for suspending the cathode wire, the anode plate and the attached deposited dust, and the vertical load formed by the dead weight of the process equipment and the deposited dust is transmitted to the upright post by the box body top beam, so that the upright post bears the axial pressure. The box body framework upright column is an H-shaped steel column and supported by the wall plate, and the wall plate can not only share load for the upright column, but also provide lateral support for the upright column, and exert stressed skin effect. The box body wallboard is a stiffening steel plate, and in order to guarantee the leakproofness, the wallboard is connected with the edge of a wing on one side of the H-shaped steel stand column in a continuous welding mode to form a structure whole working together. This wallboard-column structural system requires consideration of the stressed skin effect of the wallboard to share load and provide restraint for the column, and thus there is no reliable quantitative determination method as to its stable load bearing capacity under axial compression.
In view of the fact that previous research and development results do not relate to a method for determining the axial pressure stable bearing capacity of a dust remover box body upright post on the premise that the action of stressed skin of a wallboard is accurately considered, the invention researches the influence of different initial defects on the axial pressure stability of the box body upright post, and provides a method for determining the axial pressure stable bearing capacity of the dust remover box body upright post after determining the influence rule of different stiffening wallboard structure parameters and upright post section structure parameters on the stability of the box body upright post under the action of axial pressure, thereby providing a technical basis for the box body structure design of the dust removing equipment.
Disclosure of Invention
[ problem ] to
The invention aims to provide a method for accurately evaluating the stable bearing capacity of an axial compression column of a dust remover box body aiming at the vacancy of a design method for the axial compression stable bearing capacity of an upright column in the existing dust remover box body enclosure system, and quantitatively researches the influence rule of each parameter under the condition of considering the initial geometric defect of a wallboard-upright column structure system and the influence of residual stress and residual deformation generated in the welding process of a wallboard and an upright column to obtain a method for calculating the stable bearing capacity of the axial compression column of the dust remover box body characterized by multiple structural geometric parameters.
[ solution ]
The invention provides a method for determining the axial pressure stable bearing capacity of a dust remover box body stand column, which is characterized in that the axial pressure stable coefficient of the dust remover box body stand column is used
Figure GDA0002471099020000011
On the basis, the stable bearing capacity N of the box body upright post under axial pressure is obtainedrThe concrete formula is as follows:
Figure GDA0002471099020000012
in the formula (1), the reaction mixture is,
Figure GDA0002471099020000023
is the axial pressure stability coefficient of the upright post of the dust remover box body, AHIs the sectional area of a single-limb H-shaped steel upright column with the unit of mm2F is the design value of the strength of the steel material and the unit is N/mm2Coefficient of 0.95 for achieving stable ultimate bearing capacityThe safety coefficient of time-instability deformation and the section plasticity development of the upright post.
In one embodiment, the axial pressure stability factor of the upright post of the dust remover box body is obtained
Figure GDA0002471099020000024
The method comprises the following steps:
the method comprises the following steps: determining the torsion slenderness ratio lambda of the H-shaped steel upright postzWeb height H of H-shaped steel column0Web thickness t of H-shaped steel columnwWidth B of flange of H-section steel column and thickness t of flange of H-section steel columnfWall thickness t of wall panelwallAll the measured values are in mm;
step two: obtaining the axial pressure stability coefficient of the upright post of the dust remover box body according to the following formula
Figure GDA0002471099020000022
Figure GDA0002471099020000021
In one embodiment, the calculation and analysis prove that the welding residual stress between the wallboard and the upright column has no adverse effect on the axial pressure stability of the upright column, and the influence of the residual stress and the residual deformation does not need to be considered and reflected in the calculation.
In one embodiment, the wall plates of the dust collector box body are steel plates with stiffening ribs, the wall plates are continuously welded with one side flange of the upright post, the upright post is hot-rolled H-shaped steel, and the inside of the dust collector box body supports the upright post in the direction of the vertical wall plates at equal intervals.
In one embodiment, the wall thickness t of the wall panelwallIs 4-10 mm; torsion slenderness ratio lambda of H-shaped steel upright postz56-138, the flange width-thickness ratio B/tf6.4-23.6, and the height-thickness ratio h of web plate0/tw15-58.8, the ratio t of the wall thickness of the wall plate to the thickness of the flangewall/tfIs 0.4-0.75.
In one embodiment, the calculation, comparison and analysis of the column axial compression stability capacities in the precipitator structures of different geometric configurations is numerically simulated by means of the finite element software ANSYS.
In one embodiment, the welding residual stress and residual deformation, and wallboard wall thickness t are influenced by the initial geometric defect of the wallboard-column structure system and the residual stress generated in the welding process of the wallboard and the columnwallWidth w of stiffening wallboard, stiffness of stiffening rib, spacing of stiffening rib, connecting plate and transverse supporting spacing l0The bending slenderness ratio lambda of the upright column around the y-y axis of the section symmetry axisyWall plate wall thickness to flange thickness ratio twall/tfCross-sectional torsional slenderness ratio lambdazHeight-thickness ratio h of cross-section web0/twFlange width-thickness ratio B/t of cross sectionfAnd quantitatively researching the influence rule of the stable bearing capacity of the box body upright column, and obtaining an upright column axial pressure stable bearing capacity calculation formula represented by the geometric parameters of the multi-item structure by utilizing least square fitting.
In one embodiment, the calculated values using equations (1) and (2) and the finite element calculations result in a stable ultimate bearing capacity relative error of 3.2% on average.
[ advantageous effects ]
The method for determining the axial pressure stable bearing capacity of the upright post of the dust remover box body has the advantages that:
1. the application range is wider: the investigation range of each geometric parameter is based on the actual dust remover structure and the wall thickness t of the wallboardwallIs 4-10 mm; h-shaped steel column bending-torsion slenderness ratio lambdaz56-138, the flange width-thickness ratio B/tf6.4-23.6, and the height-thickness ratio h of web plate0/tw15-58.8, the ratio t of the wall thickness of the wall plate to the thickness of the flangewall/tfIs 0.4-0.75.
2. The reliability is good: firstly, the adverse effects of structural initial geometric defects and welding residual stress are fully considered; secondly, the related influences of integral instability and local instability in the instability process of the upright column are fully considered, and the stressed skin effect of the wallboard on the upright column is fully considered; thirdly, the axial center pressed stable limit bearing capacity data of various dust remover box bodies obtained by finite element calculation is subjected to least square fitting, the relative error between the calculation value of the calculation formula and the stable limit bearing capacity obtained by the finite element calculation is about 3.2%, and the fitting formula is accurate and reliable.
3. The use is convenient: a comprehensive formula is adopted, and a stable bearing capacity design value of the vertical column under the action of axial pressure is directly obtained by inputting structural geometric parameters and can be used for design and production units to refer to.
Drawings
FIG. 1 is a schematic view of a dust collector stiffened panel-column structural system;
FIG. 2 is a schematic cross-sectional view of a column;
FIG. 3 is a schematic view of the cross-sectional form of the column and the application of a disturbance load;
FIG. 4 is a graph showing the variation in the distribution of the axial residual stress of the maximum cross section of the deformation during column failure;
FIGS. 5(a), 5(b), and 5(c) are graphs showing the relationship between the relative stable load bearing capacity and whether the residual stress is considered;
FIG. 6 is a load displacement curve of the column in different initial geometric defect modes;
FIG. 7(a), FIG. 7(b), FIG. 7(c), FIG. 7(d), and FIG. 7(e) are the stability factor of the column
Figure GDA0002471099020000034
Wall thickness t of wall platewallThe relationship curve of (1);
FIG. 8(a) and FIG. 8(b) show the stability factor of the column
Figure GDA0002471099020000031
A curve relating to the width w of the wall panel;
FIG. 9(a), FIG. 9(b), FIG. 9(c), and FIG. 9(d) are the stability factor of the column
Figure GDA0002471099020000032
A curve relating to the support spacing;
FIG. 10(a), FIG. 10(b), FIG. 10(c), FIG. 10(d), and FIG. 10(e) are the stability factor of the column
Figure GDA0002471099020000033
Length and width of torsionRatio λZThe relationship curve of (1);
FIG. 11(a), FIG. 11(b), FIG. 11(c), FIG. 11(d), and FIG. 11(e) are the stability factor of the column
Figure GDA0002471099020000035
Height to thickness ratio h of web0/twThe relationship curve of (1);
FIG. 12(a), FIG. 12(b), FIG. 12(c), and FIG. 12(d) are graphs showing the stability factor of the column
Figure GDA0002471099020000036
Width to thickness ratio of flange B/tfThe relationship of (1).
Detailed Description
The following provides a method for determining the axial pressure stable bearing capacity of the upright post of the dust remover box body, which is provided by the invention and is further explained in detail by combining the attached drawings and the specific embodiment. The advantages and features of the present invention will be more apparent from the following examples. It is to be understood that the embodiments described herein are illustrative only and are not limiting upon the present invention.
Under the condition of considering the influence of the initial defects of the structure, the invention carries out numerical simulation on the calculation, comparison and analysis of the axial pressure stable bearing capacity of the upright post in the dust remover structures with different geometric structures through finite element software ANSYS, wherein the stiffening wallboard-H-shaped steel upright post structure system of the dust remover is shown in the attached drawing 1, and the cross section form of the upright post is shown in the attached drawing 2. The finite element computational analysis process is illustrated as follows:
1. a definition unit: all structural components were simulated using the Shell181 cell.
2. Definition of materials: considering the nonlinear influence of materials, the steel materials adopt an ideal elastic-plastic model, and whether yielding occurs is judged according to the Von-Mises criterion. The dust remover is made of Q235 steel with yield strength fy235MPa, the elastic modulus E is 2.06 × 105MPa, and the Poisson ratio v is 0.3, and the structural response path is tracked by adopting an arc length method.
3. Applying a constraint condition: the top ends of the wall boards of the box body are connected with the stiffening top board of the box body, so that the translation constraint vertical to the direction (Y direction) of the wall boards is applied to the top boundary of the wall boards. The bottom end of the wallboard is connected with the ash bucket stiffening wallboard, so that the translation constraint vertical to the wallboard direction is applied to the boundary of the bottom end of the wallboard. The vertical columns are restrained by wallboard stiffening ribs (vertical to the direction of the wallboard) which are arranged at equal intervals, and translation restraint vertical to the direction of the wallboard is exerted at the joint of the vertical columns and the wallboard stiffening ribs. And applying translation constraint in three directions at the column bottom of the middle upright column. Because the flue gas in the box is often high temperature, in order to release temperature deformation, the bottom of the upright posts on two sides only applies the restraint along the height direction (Z direction) of the wallboard and the direction perpendicular to the wallboard so as to realize that the structure can be deformed in a telescopic way in the plane (X direction) of the wallboard.
4. And (3) applying a load condition: the top of the dust remover box body is provided with a supporting beam used for suspending a cathode wire, an anode plate and attached accumulated dust, and the vertical load formed by the process equipment and the dead weight of the accumulated dust is transmitted to the upright post by the box body top beam, so that the upright post bears the axial pressure. Therefore, the uniform vertical line load is applied to the top of the middle upright column to an extreme point, and the axial stable bearing capacity corresponding to the upright column at the moment is defined as Ncr. Defining the stability factor of the axial pressure of the column when acting
Figure GDA0002471099020000041
Because the stiffening wallboard shares part of load for the upright column, the load borne by the H-shaped steel section at the top of the upright column is necessarily smaller than the applied external load, and therefore the applied ultimate load is possibly larger than the full-section yield load (A)Hfy) Thus, therefore, it is
Figure GDA0002471099020000042
There are cases where the value is greater than 1.
5. Construction of initial geometric defects: geometric defects of all structural parts of the dust collector are inevitable and have certain randomness, and in order to ensure the reliability of the method for determining the stable bearing capacity, the initial geometric defects which are relatively unfavorable need to be introduced. When the upright column bears the axial load, the wallboard plays a role of stressed skin, and the upright column of the box body is in elastic-plastic bending-torsion instability close to the section of the front half part of the area below the top of the column. The initial geometric deformation form of the box body upright post, which is sensitive to the axial compression stability, is the initial bending deformation of the cross section of the upright post. At the same time, when it is maximumInitial geometric deformation occurs in high axial force regions near the column top, which is more detrimental to the column stability of the box. Therefore, during modeling, a certain gradient is formed when the box body supports the top of the upright post and loads are applied, so that the top of the upright post is eccentric, and the eccentricity e around the x axisxIs 0.001H, H is the column height, and the eccentricity e around the y-axisy0.001H; simultaneously, uniformly distributing interference loads p on one side of the front flange within the range of 0.02H below the top of the column, taking the resultant force of the lateral interference loads, namely 0.02pH, as 1/1000 of the load N applied to the top of the column as shown in the attached drawing 3, and synchronously loading with the top of the column. And loading the structure to a limit load, taking the structural deformation form when the load reaches an extreme point as an initial geometric defect mode, and controlling the maximum initial geometric deformation amplitude of the middle upright column to be H/1000, so that a box body calculation model with a perfect structural extreme point defect mode applying directional interference is constructed. The defect model mainly considers the initial bending deformation of the cross section below the column top, considers the initial bending of the column around the two main shafts and the initial bulging of the wallboard, simultaneously ensures the high axial force area of the position with the maximum defect in 0.02H below the column top, and fully considers the adverse effect of the initial geometric defect.
6. Simulating welding residual stress, namely, continuously welding and connecting a box body supporting upright post which is hot-rolled H-shaped steel with a rear flange and a wallboard, wherein the welding residual stress influences the stability of the upright post, simulating welding shrinkage by applying a negative temperature delta T to the connecting edge of the rear flange and the wallboard of the box body upright post so as to introduce the welding residual stress and residual deformation, and taking the linear expansion coefficient α of a steel material as 1.2 × 10-5(1/℃)。
The following embodiments show the effect of welding residual stress and residual deformation on the stable bearing capacity of the upright post.
Example 1:
the section of the vertical column of the dust collector box body is H250 × 250 × 9 × 14(mm) (the height of the section is H ×, the width of a flange is B ×, the thickness of a web is tw× thickness t of flangef) The width w of the wall board is 4010mm, and the thickness t of the wall boardwallIs 4mm, the interval between the stiffening ribs of the wallboard is l0Is 6220 mm.
Example 2:
the section of the upright post of the dust collector box body is H294 × 200 × 8 × 12(mm), and the wall boardWidth w is 4010mm and wall thickness twallIs 6mm, the interval between the stiffening ribs of the wallboard is l0Is 3110 mm.
Example 3:
the section of the upright post of the dust collector box body is H250 × 250 × 9 × 14, the width w of the wallboard is 4010mm, and the thickness t of the wallboardwallIs 4mm, the interval between the stiffening ribs of the wallboard is l0Is 3110 mm.
In order to fully consider the influence of the initial geometric defect, the welding residual stress and the residual deformation on the axial compression stability of the stand column, the welding residual stress and the residual deformation are introduced into the embodiment 1 with the initial bending-torsion deformation geometric defect, and when the axial maximum residual stress value sigma on the section of the embodiment 1 isrs,z,maxUp to 0.94fyWhen the column is broken, the axial residual stress distribution of the maximum deformation section is shown in figure 4, and tensile stress is taken as positive, and compressive stress is taken as negative. FIG. 4 shows that the residual tensile stress decays rapidly as the web approaches the edge of the rear flange; the web mainly presents residual compressive stress and has small amplitude; while the column front flange, which is remote from the wall panel, exhibits little residual tensile stress. The post residual stress distribution characteristics are similar in the different structural wallboard-post structural systems.
The welding residual stress and the welding residual deformation are necessarily generated simultaneously in the process of introducing the welding defect, influence differences of combined action of the residual stress and the residual deformation and only independent action of the residual deformation are researched in the embodiments 1, 2 and 3, and the relation curve of relative stable bearing capacity and whether the residual stress is considered is obtained as shown in fig. 5(a), 5(b) and 5(c), wherein the abscissa of the curve is the maximum residual stress amplitude, and the ordinate is the stable bearing capacity N of the stand column after the welding defect is introducedu,rStable bearing capacity N without welding defectuThe ratio of (a) to (b).
Comparing the stable bearing capacity with or without considering the residual stress, it can be found that for different structural models, the stable bearing capacity after introducing the residual stress is basically greater than that without considering the residual stress, which indicates that the residual stress is favorable for the stability of the box body upright column, but the amplitude is very small and is not more than 1.5%. When only the welding residual deformation is introduced, the stable bearing force ratio with and without the welding residual deformation is close to1, the welding residual deformation only has little influence on the stability of the box body upright post. This is because the welding residual deformation is small in magnitude even when the residual stress reaches 0.94fyIn the process, the maximum welding deformation on the upright post is only 0.86 mm; on the other hand, the residual deformation mainly occurs in the rear flange restrained by the wallboard, and the welding deformation of the front flange in the area below the column top which is easy to destabilize is very little, so the welding residual deformation basically has no influence on the stability of the box body stand column. The welding residual deformation mode of example 1 was taken as the initial geometric defect mode, the amplitude thereof was amplified to H/1000, and the load-displacement curve at the initial flexural deformation geometric defect mode with the structure was compared with that of fig. 6, regardless of the influence of the residual stress. As can be seen from the figure, the stable bearing capacity of the box body upright post only having the initial bending-torsion deformation geometric defect mode is obviously smaller than that of the box body upright post only having the welding residual deformation defect mode, and the rigidity before buckling is also obviously smaller. In general, the welding residual stress has a slight beneficial effect on the stable bearing capacity of the box body upright post, and the welding residual deformation basically has no effect on the stability of the box body upright post, so that the influence of the residual stress and the residual deformation is not reflected in the formula for determining the axial pressure stability coefficient of the box body upright post of the dust remover.
The following examples examine the effect of wall thickness of the wall panels on the stable load bearing capacity of the box uprights.
Example 4:
the section of the upright post of the dust collector box body is H300 × 300 × 10 × 15(mm), and the thickness t of the wallboardwall6mm, wallboard width w 5614mm, wallboard stiffener size L125 × 80 × 8(mm), lateral brace spacing l0Is 3117 mm.
Example 5:
the section of the upright post of the dust collector box body is H200 × 150 × 6 × 9(mm), and the thickness t of the wallboardwall4mm, wallboard width w 3500mm, wallboard stiffener dimension L100 × 63 × 6(mm), lateral brace spacing l03510 mm.
Example 6:
the section of the upright post of the dust collector box body is H294 × 200 × 8 × 12(mm), and the thickness t of the wall boardwallIs 4mm and the width w of the wall plate is4030mm, wallboard stiffener size L125 × 80 × 8(mm), lateral support spacing l05200 mm.
Example 7:
the section of the upright post of the dust collector box body is H350 × 350 × 10 × 16(mm), and the thickness t of the wallboardwall6mm, wallboard width w 4030mm, wallboard stiffener dimension L L125 × 80 × 8(mm), lateral brace spacing l0Is 7200 mm.
Example 8, example 9 and example 10:
examples 8, 9 and 10 only varying wallboard thickness t relative to example 4wallSpecific structural parameters and stability factor
Figure GDA0002471099020000061
As shown in table 1.
Example 11, example 12, example 13, example 14 and example 15:
example 11, example 12, example 13, example 14 and example 15 only the wallboard thickness t was varied relative to example 5wallSpecific structural parameters and stability factor
Figure GDA0002471099020000062
As shown in table 1.
Example 16, example 17, example 18, example 19 and example 20:
example 16, example 17, example 18, example 19 and example 20 only the wallboard thickness t was varied relative to example 6wallSpecific structural parameters and stability factor
Figure GDA0002471099020000071
As shown in table 1.
Example 21, example 22, example 23, example 24 and example 25:
example 21, example 22, example 23, example 24 and example 25 only the wallboard thickness t was varied relative to example 7wallSpecific structural parameters and stability factor
Figure GDA0002471099020000072
As shown in table 1.
Table 1 example structural geometry and stability factor
Figure GDA0002471099020000081
Examining comparative example groups 4, 8, 9, 10, example groups 5, 11, 12, 13, 14, 15, example groups 6, 16, 17, 18, 19, 20 and example groups 7, 21, 22, 23, 24, 25, the stability factor of the columns
Figure GDA0002471099020000082
Wall thickness t of wall platewallThe relationship curves of (a) are shown in fig. 7(a), fig. 7(b), fig. 7(c), fig. 7(d), and fig. 7 (e). When the thickness of the wallboard is increased, the stable bearing capacity of the upright column generally tends to rise, but the amplitude is very small, and when the thickness of the wallboard is increased by 2.25 times, the stable bearing capacity of the upright column
Figure GDA0002471099020000083
The variation amplitude does not exceed 2%. The box body wall plate mainly plays a role in sealing an electric field in the enclosure box body and bearing negative pressure and wind load in actual engineering, the design wall thickness is generally determined by the plate resisting transverse load, the design wall thickness is not too large, the proportion of steel consumption occupied by the wall plate is large, material waste can be caused by excessively increasing the wall plate thickness, the wall plate thickness applied in the actual engineering still belongs to a thinner thickness range, the data show that in the range, the change of the wall plate wall thickness has a small beneficial effect on the stable bearing capacity of the upright post, and the overall influence is not large. Meanwhile, when the thickness of the wallboard is only 4mm, the instability form of the upright column still represents the bending instability at the column cap defect, so that the enough lateral support can be provided for the upright column even if the wallboard is weak, and the bending instability of the upright column around the y-y axis can not occur under the constraint of the wallboard.
According to the investigation result and analysis, the influence of the wall thickness of the wallboard on the stability of the upright post is small, so that the influence of the parameter is not considered separately when the calculation method for the axial pressure stable bearing capacity of the upright post of the dust remover box body is provided by the invention.
The following examples examine the effect of stiffened panel width on the stable load bearing capacity of a box column.
Example 26:
the section of the upright post of the dust collector box body is H294 × 200 × 8 × 12(mm), and the thickness t of the wall boardwall8mm, wallboard width w 2125mm, wallboard stiffener dimension L100 × 63 × 6(mm), lateral brace spacing l0Is 3110 mm.
Example 27:
the section of the upright post of the dust collector box body is H250 × 250 × 8 × 12(mm), and the thickness t of the wall boardwall6mm, wallboard width w 4010mm, wallboard stiffener size L125 × 80 × 8(mm), lateral brace spacing l0Is 3110 mm.
Example 28, example 29, example 30 and example 31:
example 28, example 29, example 30 and example 31 only the wallboard width w, specific construction parameters and stability factor were varied relative to example 26
Figure GDA0002471099020000095
As shown in table 2.
Example 32, example 33, example 34, example 35, example 36, example 37, example 38 and example 39:
example 32, example 33, example 34, example 35, example 36, example 37, example 38 and example 39 the wallboard width w, specific construction parameters and stability factor were varied relative to example 27
Figure GDA0002471099020000092
As shown in table 2.
Table 2 example structural geometry and stability factor
Figure GDA0002471099020000091
Examining the stability factor of the columns in the comparative example groups 26, 28, 29, 30, 31 and in the example groups 27, 33, 34, 35, 36, 37, 38, 39
Figure GDA0002471099020000093
The curves of the relationship with the wall board width w are shown in fig. 8(a) and 8 (b). When the width of the wallboard is increased by 240 percent, the upright post
Figure GDA0002471099020000094
The value does not change by more than 0.5%, indicating that changing the width of the wallboard has little effect on the stability of the stud. The reason for analyzing the axial force is that the wallboard shares the axial force for the stand column, provides constraint for the stand column and can be loaded. The wall panel lattice enclosed by the stiffening ribs and the upright columns on the two sides is generally large in side length, thin in plate thickness and easy to bend after being subjected to pressure and shearing force due to the initial defect. During the initial loading period, the middle area of the wallboard cell undergoes significant buckling deformation and then develops rapidly. In the middle and later loading stages, the middle area of the wallboard grid is basically out of work due to buckling, and the wallboard in the area adjacent to the upright post can be loaded continuously. Thus, wall panel widening or narrowing has little effect on the wall panel load bearing performance in the edge region and little effect on column stability.
According to the investigation result and analysis, the influence of the width of the stiffening wallboard on the stability of the upright post is small, so that the influence of the parameter is ignored when the method for calculating the axial pressure stable bearing capacity of the upright post of the dust remover box body is provided by the invention.
The following examples examine the effect of stiffening rib stiffness on the stable load bearing capacity of a box upright.
Example 40:
the section of the upright post of the dust collector box body is H250 × 250 × 8 × 12(mm), the width w of the wall board is 4812mm, and the thickness t of the wall boardwall6mm, wallboard stiffener size L125 × 80 × 8(mm), wallboard stiffener spacing l0Is 3110 mm.
Example 41:
the section of the upright post of the dust collector box body is H275 × 125 × 6 × 9.8.8 (mm), the width w of the wallboard is 4010mm, and the thickness t of the wallboardwall6mm, wallboard stiffener size L125 × 80 × 8(mm), wallboard stiffener spacing l0Is 6220 mm.
Example 42:
the section of the upright post of the dust collector box body is H294 × 200 × 8 × 12(mm), the width w of the wall board is 2125mm, and the thickness t of the wall boardwall7mm, wallboard stiffener size L100 × 63 × 6(mm), wallboard stiffener spacing l0Is 3110 mm.
Example 43, example 44, example 45 and example 46:
example 43, example 44, example 45 and example 46 only change the wall thickness of the angle stiffener, the specific construction parameters and stability factor relative to example 40
Figure GDA0002471099020000105
As shown in table 3.
Example 47, example 48, example 49 and example 50:
examples 47, 48, 49 and 50 only change the wall thickness of the angle stiffener, the specific construction parameters and the stability factor relative to example 41
Figure GDA0002471099020000103
As shown in table 3.
Example 51, example 52, example 53 and example 54:
example 51, example 52, example 53 and example 54 only change the wall thickness of part of the angle stiffener compared with example 42, and the specific construction parameters are shown in table 4.
TABLE 3 structural geometry and stability factor of the examples (uniform wall thickness for all angle stiffeners)
Figure GDA0002471099020000101
Table 4 structural geometry and stability factor of the examples
Figure GDA0002471099020000102
Examine the column stability factor in comparative example groups 43, 44, 45, 46 and example groups 47, 48, 49, 50
Figure GDA0002471099020000104
The relation with the wall thickness of the angle steel stiffening rib shows that the stability coefficient of the H-shaped steel column with different sections under the condition of different angle steel stiffening ribs is increased slightly along with the increase of the rigidity of the stiffening rib. When the rigidity of the stiffening rib is increased to a certain value, the improvement of the stability of the upright post is basically stopped. Because the wall plate can be used for sharing load for the upright column, the axial pressure borne by the cross section of the upright column is quickly attenuated downwards along the height of the upright column, and the axial pressure borne by the position 0.02H away from the top of the upright column is only 85% of the load applied by the top of the upright column on average, so that the influence of stiffening ribs at different positions on the stability of the upright column is presumed to be different. When the group of comparative examples 51, 52, 53, 54 is examined and the rigidity of the top stiffener is increased only, the column
Figure GDA0002471099020000111
The value is improved by 4.9%; when the rigidity of the top stiffening rib is kept unchanged and the rigidity of all the stiffening ribs below is increased, the upright post
Figure GDA0002471099020000112
The value is improved by 3.5 percent; when the rigidity of all stiffening ribs is increased, the upright post
Figure GDA0002471099020000113
The value is improved by 7.8%, because the instability of the upright column mainly occurs in the area below the top of the adjacent column, the top angle steel stiffening rib can directly restrain the deformation of the upright column and transfer the load of the upright column, the stiffness of the stiffening rib in the area of the top has a large influence on the stability of the upright column, and the stiffening rib far away from the instability area of the upright column at the top of the column has a relatively small influence on the stability of the upright column.
From the above observations and analysis, from the perspective of an optimized design, only the stiffener sections in the top area can be designed to be stiffer, while the stiffeners below in the wallboard can be designed to be less stiff. Considering that the rigidity of the angle steel stiffening rib of the wallboard is higher in design in order to limit excessive deformation of the wallboard during engineering actual design, and the improvement of the stability of the upright post is basically stopped after the rigidity of the stiffening rib is increased to a certain value, the method for calculating the axial pressure stable bearing capacity of the upright post of the dust remover box body does not reflect the influence of the rigidity of the stiffening rib of the wallboard any more.
The following examples examine the effect of the spacing of the stiffening ribs on the stable load bearing capacity of the box uprights.
Example 55:
the section of the upright post of the dust collector box body is H294 × 200 × 8 × 12(mm), the width w of the wall board is 2125mm, and the thickness t of the wall boardwall8mm, wallboard stiffener size L100 × 63 × 6(mm), wallboard stiffener spacing 1040mm, lateral brace spacing l0Is 3110 mm.
Example 56:
the section of the upright post of the dust collector box body is H250 × 250 × 9 × 14(mm), the width w of the wallboard is 4010mm, and the thickness t of the wallboardwall6mm, wallboard stiffener size L125 × 80 × 8(mm), wallboard stiffener spacing 2080mm, lateral brace spacing/0Is 3110 mm.
Example 57 and example 58:
examples 57 and 58 only change the wallboard angle stiffener spacing, specific construction parameters and stability factor relative to example 55
Figure GDA0002471099020000114
As shown in table 5.
Example 59, example 60 and example 61:
examples 59, 60 and 61 Only changes in wallboard Angle stiffener spacing, specific construction parameters and stability factor relative to example 56
Figure GDA0002471099020000115
As shown in table 5.
Table 5 structural geometry and stability factor of the examples
Figure GDA0002471099020000121
Examine the column stability factor in comparative example groups 55, 57, 58 and example groups 56, 59, 60, 61
Figure GDA0002471099020000123
The relationship with the angle stiffener spacing indicates for the exampleGroups 55, 57, 58, have wallboard stiffener spacing expanded 4 times,
Figure GDA0002471099020000124
the value does not vary by more than 0.3%. Examining example groups 56, 59, 60, 61, the wallboard stiffener spacing was expanded 8 times, which is
Figure GDA0002471099020000125
The value does not vary by more than 0.8%. Changing the spacing of the wall panel stiffeners primarily changes the aspect ratio of the wall panel cells, which affects the stability of the wall panel when stressed and sheared. In the rib interval scope of probably stiffening in engineering, the unstability of stand takes place between the first and second stiffening rib of top regional (generally in 300mm within range below the capital), even if consequently encrypt the stiffening rib, firstly the unstability of the regional stand of the unable direct constraint top of stiffening rib warp, secondly the buckling still can take place for the later stage wallboard in the loading, and the work is withdrawed from to the most wallboard in middle part, and it has not obvious effect to help the stand to bear the weight of to change wallboard stability. Thus, wallboard stiffener spacing has little effect on column stability
According to the investigation result and analysis, the influence of the space between the stiffening ribs of the wallboard on the stability of the upright post is small, so that the influence of the parameter is not considered when the method for calculating the axial pressure stable bearing capacity of the upright post of the dust remover box body is provided.
The following examples examine the effect of the connecting plates on the stable bearing capacity of the box upright.
Example 62, example 63 and example 64:
examples 62, 63 and 64 were carried out by changing only the conditions of the connection plates with respect to example 60 (thickness of the connection plate: 14mm), and the specific construction parameters were as shown in Table 5.
TABLE 6 structural geometry and stability factor of the examples
Figure GDA0002471099020000122
When the comparative example groups 60, 62, 63 and 64 are examined, the stability of the columns is not changed obviously along with the increase of the rigidity of the connecting plates. Compared with the situation that the rigidity of the connecting plate is infinite, the stability coefficient of the upright post is only improved by 0.2 percent under the condition of no connecting plate. The buckling of the studs typically occurs in the region between 200 and 300mm below the top of the stud, where the cross-section of the stud undergoes large deformations. A calculation model is established according to engineering practice, the distance between connecting plates is the distance between the angle steel stiffening ribs, and the arrangement of the connecting plates is not too dense within the range of the distance between the stiffening ribs possible in engineering, so that the deformation of the cross section of the upright column in the instability area cannot be directly and effectively restrained. And the restraint effect of the connecting plate far away from the instability area on the instability deformation of the stand column is slight, so that the influence of the rigidity improvement of the connecting plate on the axial pressure stability of the stand column is small in the range of the arrangement distance of the connecting plates possible in engineering.
According to the investigation result and analysis, the influence of the connecting plate on the stability of the upright post is small, so that the influence of the parameters of the connecting plate is not considered when the calculation method for the axial pressure stable bearing capacity of the upright post of the dust remover box body is provided.
The following examples examine the transverse bracing spacing l0The influence on the stable bearing capacity of the upright column of the box body.
Example 65:
the section of the upright post of the dust collector box body is H250 × 250 × 9 × 14(mm), the width w of the wallboard is 4550mm, the wall thickness t of the wallboard is 7mm, the height H of the upright post is 21460mm, the size of the stiffening rib of the wallboard is L125 × 80 × 8(mm), and the transverse support interval l0Is 2000 mm.
Example 66:
the section of the upright post of the dust collector box body is H250 × 175 × 7 × 11(mm), the width w of the wallboard is 3850mm, the wall thickness t of the wallboard is 6mm, the height H of the upright post is 14972mm, the size of the stiffening rib of the wallboard is L125 × 80 × 8(mm), and the transverse support spacing l02252 mm.
Example 67:
the section of the upright post of the dust collector box body is H294 × 200 × 8 × 12(mm), the width w of the wallboard is 4200mm, the wall thickness t of the wallboard is 6mm, the height H of the upright post is 19460mm, the stiffening rib dimension of the wallboard is L125 × 80 × 8(mm), and the transverse support interval l0Is 3000 mm.
Example 68:
the section of the upright post of the dust collector box body is H300 × 300 × 10 × 15(mm), and the wallThe width w of the plate is 4900mm, the wall thickness t of the wallboard is 7mm, the height H of the upright post is 25460mm, the size of the stiffening rib of the wallboard is L125 × 80 × 8(mm), and the transverse supporting interval l0Is 6000 mm.
Example 69, example 70 and example 71:
example 69, example 70 and example 71 only the transverse bracing spacing l was varied in comparison with example 650Of (d), specific constructional parameter lambdaxAnd coefficient of stability
Figure GDA0002471099020000131
As shown in table 7.
Example 72, example 73 and example 74:
examples 72, 73 and 74 in relation to example 66 only the transverse bracing spacing/was varied0Of (d), specific constructional parameter lambdaxAnd coefficient of stability
Figure GDA0002471099020000132
As shown in table 7.
Example 75, example 76 and example 77:
examples 75, 76 and 77 vary only the transverse bracing spacing l in comparison to example 670Of (d), specific constructional parameter lambdaxAnd coefficient of stability
Figure GDA0002471099020000134
As shown in table 7.
Example 78, example 79 and example 80:
examples 78, 79 and 80 in relation to example 68, the transverse bracing spacing l is only varied0Of (d), specific constructional parameter lambdaxAnd coefficient of stability
Figure GDA0002471099020000133
As shown in table 7.
Table 7 structural geometry and stability factor of the examples
Figure GDA0002471099020000141
Examine and compare four example groups, the column stability factor
Figure GDA0002471099020000144
The graphs relating to the support pitch are shown in fig. 9(a), 9(b), 9(c), and 9 (d). Considering the comparative example groups 65, 69, 70, 71, the bending slenderness ratio λ was increased as the supporting pitch was increasedxAnd also increases. When the supporting distance is increased from 2000mm to 10000mm, lambdax5.08 times of expansion and column stability factor
Figure GDA0002471099020000142
The reduction is 6.2 percent, when the supporting distance is increased from 4000mm to 5000mm, the lambda is increasedx1.25 times of expansion and stability factor
Figure GDA0002471099020000143
The reduction is 0.7%, when the supporting spacing is 2000mm, 4000mm and 5000mm, the instability of the upright column is represented as the bending and twisting instability at the column head defect, and when the supporting spacing is 10000mm, the instability of the upright column is mainly represented as the bending instability of the first span-middle upper area at the top. Examining example groups 66, 72, 73, 74, example groups 67, 75, 76, 77 and example groups 67, 78, 79, 80 when λ isxWhen the ratio of length to width λ exceeds 55, the vertical column exhibits bending instability in many cases, and it is known that the ratio of length to width λ restricts bending instability of the vertical columnxBelow 55, the possibility of buckling of the column about the x-x axis is substantially eliminated, and only buckling at the top of the column is noted and control measures are taken.
Because the actually designed dust remover structure can arrange the transverse supports with equal intervals in order to ensure the lateral rigidity of the upright post, the supporting intervals can not be overlarge, and the transverse supporting intervals of the dust remover in general engineering can be controlled within 6m, thereby basically ensuring the lambda of the upright postxNot exceeding 55. According to the investigation result and analysis, the influence of the transverse support distance on the stability of the upright is small, so that the influence of the parameter is not considered when the calculation method for the axial pressure stable bearing capacity of the upright of the dust remover box body is provided.
The following examples examine the bending slenderness ratio λ of a pillar about the y-y axis of symmetry of the sectionyThe influence on the stable bearing capacity of the upright column of the box body.
Example 81:
the section of the upright post of the dust collector box body is H250 × 250 × 9 × 14(mm), the width w of the wallboard is 4010mm, the wall thickness t of the wallboard is 6mm, the height H of the upright post is 17.020m, the size of the stiffening rib of the wallboard is L125 × 80 × 8(mm), and the transverse support interval l0Is 4140 mm.
Example 82:
the section of the upright post of the dust collector box body is H270 × 125 × 6 × 9.8.8 (mm), the width w of the wallboard is 4010mm, the wall thickness t of the wallboard is 8mm, the height H of the upright post is 21.150m, the size of the stiffening rib of the wallboard is L125 × 80 × 8(mm), and the transverse support spacing l0Is 3110 mm.
Example 83 and example 84:
examples 83 and 84 relative to example 81, only the height H of the stud (and the overall height of the wall panel are correspondingly increased), the specific construction parameters and the stability factor are changed
Figure GDA0002471099020000155
As shown in table 8.
Example 85 and example 86:
examples 85 and 86 only change the stud height H (and a corresponding increase in the overall wall panel height) and the specific construction parameters and stability factor relative to example 82
Figure GDA0002471099020000153
As shown in table 8.
TABLE 8 structural geometry and stability factor of the examples
Figure GDA0002471099020000151
The vertical column may have bending instability around the y-y axis of the symmetry axis, in order to examine the influence of slenderness ratio around the y-y axis, the design model keeps the transverse support distance and the residual structure unchanged, and the height H of the vertical column is changed to control the slenderness ratio lambda of the bending instabilityyTo determine pairs therefromThe effect of column stability.
When the groups 81, 83 and 84 of the comparative examples were examined, the column height of the column was increased by 1.73 times, λyIncreased by 1.8 times and stable coefficient of upright post
Figure GDA0002471099020000154
Only 0.074% change; examining the groups 82, 85, 86 of comparative examples, the column height increased by a factor of 1.73, lambdayIncreased by 1.8 times and stable coefficient of column
Figure GDA0002471099020000156
Only 0.081% change. With the obvious increase of the height of the upright column, the wallboard has stronger shear rigidity in the plane of the wallboard, and effectively restrains the upright column from bending deformation around the y-y axis, so that the upright column is difficult to bend and lose stability around the y-y axis, and lambda is ensuredyHas little effect.
From the above examination results and analysis, the bending slenderness ratio λ around the axis of symmetryyThe influence on the stability of the upright post is small, so that the influence of the parameter is not considered when the calculation method for the axial pressure stable bearing capacity of the upright post of the dust remover box body is provided.
The following examples examine the wall panel to flange thickness ratio twall/tfThe influence on the stable bearing capacity of the upright column of the box body.
Example 87:
the section of the upright post of the dust collector box body is H367 × 250 × 10 × 15(mm), and the width-thickness ratio B/t of the flange of the section is ensuredfWeb height-thickness ratio h0/twTorsion slenderness ratio lambda of column sectionzKeeping the thickness ratio t of the wall plate to the flange unchanged and only changing the thickness ratio t of the wall plate to the flangewall/tfSpecific structural parameters and stability factors
Figure GDA0002471099020000152
As shown in table 9.
Example 88:
the section of the vertical column of the dust collector box body is H294 × 200 × 8 × 12(mm), and the width-thickness ratio B/t of the section flange is ensuredfWeb height-thickness ratio h0/twTorsion slenderness ratio lambdazRemain unchanged, only change the wall panelThickness ratio t to flangewall/tfSpecific structural parameters and stability factors
Figure GDA0002471099020000157
As shown in table 9.
Example 89:
the section of the vertical column of the dust collector box body is H220 × 150 × 6 × 9(mm), and the width-thickness ratio B/t of the flange of the section is ensuredfWeb height-thickness ratio h0/twTorsion slenderness ratio lambdazKeeping the thickness ratio t of the wall plate to the flange unchanged and only changing the thickness ratio t of the wall plate to the flangewall/tfSpecific structural parameters and stability factors
Figure GDA0002471099020000162
As shown in table 9.
Example 90:
the section of the vertical column of the dust collector box body is H195 × 128 × 5.8.8 5.8 × 8(mm), and the width-thickness ratio B/t of the flange of the section is ensuredfWeb height-thickness ratio h0/twTorsion slenderness ratio lambdazKeeping the thickness ratio t of the wall plate to the flange unchanged and only changing the thickness ratio t of the wall plate to the flangewall/tfSpecific structural parameters and stability factors
Figure GDA0002471099020000164
As shown in table 9.
Example 91:
the section of the vertical column of the dust collector box body is H280 × 280 × 10 × 15.7(mm), and the width-thickness ratio B/t of the flange of the section is ensuredfWeb height-thickness ratio h0/twTorsion slenderness ratio lambdazKeeping the thickness ratio t of the wall plate to the flange unchanged and only changing the thickness ratio t of the wall plate to the flangewall/tfSpecific structural parameters and stability factors
Figure GDA0002471099020000165
As shown in table 9.
Example 92:
the section of the vertical column of the dust collector box body is H250 × 250 × 9 × 14(mm), and the width-thickness ratio B/t of the flange of the section is ensuredfWeb height-thickness ratio h0/twTorsion slenderness ratio lambdazKeeping the thickness ratio t of the wall plate to the flange unchanged and only changing the thickness ratio t of the wall plate to the flangewall/tfSpecific structural parameters and stability factors
Figure GDA0002471099020000163
As shown in table 9.
Example 93:
the section of the vertical column of the dust collector box body is H150 × 150 × 5.4.4 5.4 × 8.4.4 (mm), and the width-thickness ratio B/t of the flange of the section is ensuredfWeb height-thickness ratio h0/twTorsion slenderness ratio lambdazKeeping the thickness ratio t of the wall plate to the flange unchanged and only changing the thickness ratio t of the wall plate to the flangewall/tfSpecific structural parameters and stability factors
Figure GDA0002471099020000166
As shown in table 9.
TABLE 9 structural geometry and stability factor of the examples
Figure GDA0002471099020000161
Looking at the comparative example groups 87, 88, 89, 90, the column stability capacity increases as the wall panel to flange thickness ratio increases. Comparing example 87 with example 90, the column stability factor increases by 1.875 times when the wallboard to flange thickness ratio increases
Figure GDA0002471099020000167
The increase was 4.05%. The thickness ratio of the wall plate to the flange changes due to the change of the thickness of the flange, the wall thickness of the wall plate is kept unchanged, the translation and torsion constraints of the wall plate in a plane provided by the upright post are unchanged, meanwhile, the wall thickness of the H-shaped steel is reduced, the wall thickness of the wall plate is unchanged, and when axial pressure is distributed, the wall plate can bear more loads, so that the stable bearing capacity of the upright post is improved. Therefore, to verify the general applicability of the above conclusions, considering comparative examples 91, 92, 93, the column stability factor increases when the wall panel to flange relative wall thickness ratio increases by 1.86 times
Figure GDA0002471099020000171
6.7% rise, also saidObviously increase the thickness ratio of wallboard and edge of a wing and can improve stand stability.
The following examples examine the cross-sectional torsional slenderness ratio λzThe influence on the stable bearing capacity of the upright column of the box body.
Example 94:
torsion slenderness ratio lambda of box body upright post of dust removerzIs 73, stability factor
Figure GDA0002471099020000175
As shown in table 10.
Example 95:
torsion slenderness ratio lambda of box body upright post of dust removerzHas a stability factor of 66
Figure GDA0002471099020000176
As shown in table 10.
Example 96:
torsion slenderness ratio lambda of box body upright post of dust removerzA stability factor of 71
Figure GDA0002471099020000173
As shown in table 10.
Example 97:
torsion slenderness ratio lambda of box body upright post of dust removerzHas a stability factor of 56
Figure GDA0002471099020000177
As shown in table 10.
Example 98:
torsion slenderness ratio lambda of box body upright post of dust removerzA stability factor of 87
Figure GDA0002471099020000178
As shown in table 10.
Example 99, example 100 and example 101:
example 99, example 100 and example 101 ensure the width-to-thickness ratio B/t of the cross-sectional flange in comparison with example 94fWeb height-thickness ratio h0/twThe thickness ratio t of the wall plate to the flangewall/tfIs maintained atBy varying only the torsional slenderness ratio lambdazSpecific structural parameters and stability factors
Figure GDA0002471099020000172
As shown in table 10.
Example 102, example 103 and example 104:
example 102, example 103 and example 104 ensure the width-to-thickness ratio B/t of the cross-sectional flange in comparison with example 95fWeb height-thickness ratio h0/twThe thickness ratio t of the wall plate to the flangewall/tfKeeping the torsional slenderness ratio lambda unchanged and only changing the torsional slenderness ratio lambdazSpecific structural parameters and stability factors
Figure GDA0002471099020000174
As shown in table 10.
Example 105, example 106, example 107 and example 108:
example 105, example 106, example 107 and example 108 ensure that the section flange width-to-thickness ratio B/t is greater than that of example 96fWeb height-thickness ratio h0/twThe thickness ratio t of the wall plate to the flangewall/tfKeeping the torsional slenderness ratio lambda unchanged and only changing the torsional slenderness ratio lambdazSpecific structural parameters and stability factors
Figure GDA0002471099020000179
As shown in table 10.
Example 109, example 110 and example 111:
example 109, example 110 and example 111 ensure the width-to-thickness ratio B/t of the cross-sectional flange in comparison with example 97fWeb height-thickness ratio h0/twThe thickness ratio t of the wall plate to the flangewall/tfKeeping the torsional slenderness ratio lambda unchanged and only changing the torsional slenderness ratio lambdazSpecific structural parameters and stability factors
Figure GDA0002471099020000183
As shown in table 10.
Example 112, example 113 and example 114:
example 112, example 113 and example 114 ensure that the width-to-thickness ratio B/t of the cross-sectional flange is higher than that of example 98fWeb height-thickness ratio h0/twThe thickness ratio t of the wall plate to the flangewall/tfKeeping the torsional slenderness ratio lambda unchanged and only changing the torsional slenderness ratio lambdazSpecific structural parameters and stability factors
Figure GDA0002471099020000182
As shown in table 10.
TABLE 10 structural geometry and stability factor for the examples
Figure GDA0002471099020000181
Considering example groups 94, 99, 100, 101, example groups 95, 102, 103, 104, example groups 96, 105, 106, 107, 108, example groups 97, 109, 110, 111 and example groups 98, 112, 113, 114, the change of the column stability factor with the torsional slenderness ratio is shown in fig. 10(a), 10(b), 10(c), 10(d), 10 (e). Torsional slenderness ratio lambdazCan influence the stability of the upright post and has a slenderness ratio lambda along with torsionzThe increase, the stable bearing capacity of stand reduces. In the five-group model, the variation amplitude of the column stability factor is the largest in the example groups 96, 105-108, and λzThe increase is 1.76 times, and the stability coefficient of the upright post is reduced by 11.8 percent. The analysis reason is that the most unfavorable defect mode of the upright column is the initial bending deformation of the column head part, when the torsional slenderness ratio of the section is increased, the torsion instability of the defect part of the upright column is easy to occur, the column head part belongs to a high-pressure stress area, the flange is twisted and quit working, the axial force is borne only by the ridge line connected with the flange and the web plate, and the lambda iszThe larger the column stability.
The following examples examine the effect of the height-thickness ratio of the cross-sectional web on the stable bearing capacity of the box upright.
Example 115:
the section of the upright post of the dust collector box body is H150 × 150 × 7 × 10(mm), the wall thickness t of the wall board is 6mm, and the transverse support dimension l05200mm, and the height-thickness ratio h of the cross-section web0/twIs 21.43, column stabilization systemNumber of
Figure GDA0002471099020000191
As shown in table 11.
Example 116:
the section of the upright post of the dust collector box body is H200 × 100 × 5.5.5 5.5 × 8(mm), the wall thickness t of the wall board is 5mm, and the transverse support dimension l0Is 4160mm, and the height-thickness ratio h of the cross-section web plate0/tw36.36, column stability factor
Figure GDA0002471099020000192
As shown in table 11.
Example 117:
the section of the upright post of the dust collector box body is H294 × 200 × 8 × 12(mm), the wall thickness t of the wall board is 6mm, and the transverse support dimension l0Is 3117mm, and the height-thickness ratio h of the web plate of the cross section0/tw16.67, column stability factor
Figure GDA0002471099020000193
As shown in table 11.
Example 118:
the section of the upright post of the dust collector box body is H300 × 300 × 10 × 15(mm), the wall thickness t of the wall board is 5mm, and the transverse support dimension l0Is 3117mm, and the height-thickness ratio h of the web plate of the cross section0/twA column stability factor of 30
Figure GDA0002471099020000194
As shown in table 11.
Example 119:
the section of the upright post of the dust collector box body is H250 × 250 × 9 × 14(mm), the wall thickness t of the wall board is 6mm, and the transverse support dimension l0Is 4157mm, and the height-thickness ratio h of the cross-section web plate0/tw27.78, column stability factor
Figure GDA0002471099020000195
As shown in table 11.
Example 120, example 121, example 122, example 123, and example 124:
example set 120, example 121,Example 122, example 123, and example 124 changed only the web wall thickness t compared to example 115wResulting in a column aspect ratio λ around the y-axisyThe change is small, and can be regarded as lambdayRemain unchanged, thus only changing the height-thickness ratio h of the web0/twSpecific structural parameters and stability factors
Figure GDA0002471099020000196
As shown in table 11.
Example 125, example 126, example 127, example 128, example 129 and example 130:
example group 125, example 126, example 127, example 128, example 129 and example 130 only change the web wall thickness t in comparison with example 116wResulting in a column aspect ratio λ around the y-axisyThe change is small, and can be regarded as lambdayRemain unchanged, thus only changing the height-thickness ratio h of the web0/twSpecific structural parameters and stability factors
Figure GDA0002471099020000197
As shown in table 11.
Example 131, example 132, example 133, example 134, example 135 and example 136:
example group 131, example 132, example 133, example 134, example 135 and example 136 only change the web wall thickness t in comparison with example 117wResulting in a column aspect ratio λ around the y-axisyThe change is small, and can be regarded as lambdayRemain unchanged, thus only changing the height-thickness ratio h of the web0/twSpecific structural parameters and stability factors
Figure GDA0002471099020000198
As shown in table 11.
Example 137, example group 138, example group 139, example 140, example 141, and example 142:
example group 137, example group 138, example group 139, example 140, example 141 and example 142 in comparison withExample 118 variation of the Web wall thickness t onlywResulting in a column aspect ratio λ around the y-axisyThe change is small, and can be regarded as lambdayRemain unchanged, thus only changing the height-thickness ratio h of the web0/twSpecific structural parameters and stability factors
Figure GDA0002471099020000199
As shown in table 11.
Example 143, example 144, example 145, example 146, example 147 and example 148:
example group 143, example 144, example 145, example 146, example 147 and example 148 only change the web wall thickness t in comparison to example 119wResulting in a column aspect ratio λ around the y-axisyThe change is small, and can be regarded as lambdayRemain unchanged, thus only changing the height-thickness ratio h of the web0/twSpecific structural parameters and stability factors
Figure GDA0002471099020000202
As shown in table 11.
TABLE 11 example structural geometry and stability factor
Figure GDA0002471099020000201
Considering comparative example groups 115, 120, 121, 122, 123 and 124, example groups 116, 125, 126, 127, 128, 129 and 130, example groups 117, 131, 132, 133, 134, 135 and 136, example groups 118, 137, 138, 139, 140, 141 and 142 and example groups 119, 143, 144, 145, 146, 147 and 148, the column stability factor is higher than the web height-to-thickness ratio h0/twThe changes are shown in fig. 11(a), 11(b), 11(c), 11(d), and 11 (e). For example set 115, 120, 121, 122, 123, 124, the column stability load capacity decreases as the web height to thickness ratio increases, the column stability factor decreases when the web thickness decreases from 13mm to 6mm, i.e., the height to thickness ratio increases from 19.23 to 41.67
Figure GDA0002471099020000203
The reduction is 7.3%. The analysis reason is that when the height-thickness ratio of the web plate is increased, the cross-section web plate is high and thin, bulging and torsional deformation can occur more easily under high-pressure stress of a column head, the area and the thickness of the flange are much larger than those of the web plate, the deformation of the flange can not be restrained by the web plate, the restraint on the flange is reduced, the constraint on the flange is small for the three-side support, the deformation and the development are fast under the action of axial force, the torsional instability occurs earlier, and the stability of the column is reduced. Examining the remaining four groups of examples, the results demonstrate the web height to thickness ratio h0/twIs an important influence factor of the stability of the upright post and is along with the height-thickness ratio h0/twThe stable bearing capacity of the upright column is reduced.
The following examples examine the section flange width to thickness ratio B/tfThe influence on the stable bearing capacity of the upright column of the box body.
Example 149:
flange width-thickness ratio B/t of box body upright post of dust removerfA column stability factor of 10
Figure GDA0002471099020000211
As shown in table 12.
Example 150:
flange width-thickness ratio B/t of box body upright post of dust removerf6.4, column stability factor
Figure GDA0002471099020000212
As shown in table 12.
Example 151:
flange width-thickness ratio B/t of box body upright post of dust removerf6.25, column stability factor
Figure GDA0002471099020000213
As shown in table 12.
Example 152:
flange width-thickness ratio B/t of box body upright post of dust removerf8.64, column stability factor
Figure GDA0002471099020000214
As shown in table 12.
Example 153, example 154 and example 155:
example 153, example 154 and example 155 ensure torsional slenderness ratio λ compared to example 149zWeb height-thickness ratio h0/twThe thickness ratio t of the wall plate to the flangewall/tfKeeping the width-thickness ratio B/t of the section flange unchanged and only changing the width-thickness ratio B/t of the section flangefSpecific structural parameters and stability factors
Figure GDA0002471099020000215
As shown in table 12.
Example 156, example 157 and example 158:
example 156, example 157 and example 158 ensured the torsional slenderness ratio λ compared to example 150zWeb height-thickness ratio h0/twThe thickness ratio t of the wall plate to the flangewall/tfKeeping the width-thickness ratio B/t of the section flange unchanged and only changing the width-thickness ratio B/t of the section flangefSpecific structural parameters and stability factors
Figure GDA0002471099020000216
As shown in table 12.
Example 159, example 160 and example 161:
example 159, example 160 and example 161 ensure torsional slenderness ratio λ compared to example 151zWeb height-thickness ratio h0/twThe thickness ratio t of the wall plate to the flangewall/tfKeeping the width-thickness ratio B/t of the section flange unchanged and only changing the width-thickness ratio B/t of the section flangefSpecific structural parameters and stability factors
Figure GDA0002471099020000217
As shown in table 12.
Example 162, example 163 and example 164:
example 162, example 163 and example 164 ensure a torsional slenderness ratio λ as compared with example 152zWeb height-thickness ratio h0/twThe thickness ratio t of the wall plate to the flangewall/tfRemain unchanged, onlyChange the width-thickness ratio B/t of the flange of the sectionfSpecific structural parameters and stability factors
Figure GDA0002471099020000218
As shown in table 12.
TABLE 12 structural geometry and stability factor of the examples
Figure GDA0002471099020000221
Considering example groups 149, 153, 154, 155, 150, 156, 157, 158, 151, 159, 160, 161 and 152, 162, 163, 164, column stability with flange width-to-thickness ratio B/tfThe variation is shown in FIGS. 12(a) to 12 (d). Along with the width-thickness ratio B/t of the flangefThe increase, stand stability is showing and is reducing. When the width-thickness ratio of the flange of the column is enlarged by 1.5 times, the stable bearing coefficient of the column
Figure GDA0002471099020000223
The reduction is 6.09 percent when the width-thickness ratio B/t is reducedfWhen the height is reduced by 0.47 times, the stability coefficient of the upright post
Figure GDA0002471099020000224
The rise was 7.55%. The analysis reason is that the plate members forming the H-shaped steel upright post mutually provide supporting constraint at the connecting part, the magnitude of the constraint force depends on the relative rigidity of the connected plate members, and when the width-thickness ratio is B/tfWhen the column is increased, the flange of the column is wide and thin, the rigidity is weakened, the constraint of the flange on the web is reduced, the bulging deformation of the web cannot be effectively constrained, and after the flange is weakened, the rigidity of the web drives the front flange to be twisted, the front flange has initial defects to enable the twisting deformation to be more severe, and finally the bearing capacity of the column is reduced. From this it can be deduced that the flange width to thickness ratio B/tfHas great influence on the stability of the upright post and has the width-thickness ratio B/tfWhen the size is increased, the stability of the upright post is reduced.
In conclusion, the invention obtains the finite element model of the wall plate-upright post structure system of the dust remover box body through nonlinear calculation of a large number of finite element models of the wall plate-upright post structure system of the dust remover box bodyAnd calculating the stable bearing capacity of the box body stand column under different geometric parameters. The investigation range of each geometric parameter is based on the actual dust remover structure and the wall thickness t of the wallboardwallIs 4-10 mm; torsion slenderness ratio lambda of H-shaped steel upright postz56-138, flange width-thickness ratio B/tf6.4-23.6, and the height-thickness ratio h of web plate0/tw15-58.8, the thickness ratio t of the wall plate to the flangewall/tfIs 0.4-0.75. Through regression analysis based on least square method on a large amount of calculation data, the axial pressure stability coefficient of the upright column of the box body
Figure GDA0002471099020000225
Can be calculated according to the formula (2).
Figure GDA0002471099020000222
In the formula (I), the compound is shown in the specification,
Figure GDA0002471099020000226
is the stability coefficient, lambda, of the dust remover box under the axial pressure of the upright postzIs the torsion slenderness ratio of the H-shaped steel upright post, H0Web height, t, of H-section steel uprightwWeb thickness of H-shaped steel column, flange width of H-shaped steel column, and tfIs the wall thickness of the flange, twallThe above measured values are in mm for the wall thickness of the wallboard.
When the upright column reaches stable ultimate bearing capacity, the web plate and the front flange in the column top area have severe plastic development, and part of structural deformation can exceed l0/500, thus providing a column axial compression stabilizing bearing capacity NrWhen considering a safe reserve coefficient of 0.95, and simultaneously controlling the deformation of the structure under the action of axial force to meet the normal use requirement, NrCalculated as follows:
Figure GDA0002471099020000231
in the formula (I), the compound is shown in the specification,
Figure GDA0002471099020000232
is the axial pressure stability coefficient of the upright post of the dust remover box body, AHIs the sectional area of a single-limb H-shaped steel upright column with the unit of mm2(ii) a f is the design value of the strength of the steel material and the unit is N/mm2。
According to the method, under the condition that the initial geometric defects of a wallboard-upright post structure system and the residual stress influence generated in the welding process of the wallboard and the upright post are considered, the influence rule of each parameter is quantitatively researched, and an upright post axial pressure stable bearing capacity calculation formula represented by a plurality of structural geometric parameters is obtained by utilizing least square fitting. The influences of the initial bending and twisting geometric defect of the H-shaped steel column, the initial concave-convex geometric defect of the wallboard and the overall stability are considered; by an index h0/twAnd B/tfReflecting the influence of the geometrical parameters of the upright columns on the local stability and reflecting the mutual constraint action between the web plate and the flange of the H-shaped steel column; by the index twall/tfThe influence of the wall thickness of the flange of the section of the wall plate and the upright column on the stable bearing capacity of the axial compression of the upright column is reflected, the relative error of the calculated value and the stable limit bearing capacity obtained by finite element calculation is about 3.2%, and the stability and the reliability of the bearing capacity are considered to be better.
Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (7)

1. A method for determining the axial pressure stable bearing capacity of the upright post of a dust remover box body is characterized in that the axial pressure stable coefficient of the upright post of the dust remover box body is used
Figure FDA0002489688270000011
On the basis, the stable bearing capacity N of the axial compression of the upright post is obtainedrThe concrete formula is as follows:
Figure FDA0002489688270000012
in the formula (I), the compound is shown in the specification,
Figure FDA0002489688270000013
is the axial pressure stability coefficient of the upright post of the dust remover box body, AHIs the sectional area of a single-limb H-shaped steel upright column with the unit of mm2F is the design value of the strength of the steel material and the unit is N/mm20.95 is a safety coefficient for controlling the instability deformation generated when the stable limit bearing capacity is reached and the section plasticity development of the upright column;
determining axial pressure stability coefficient of upright post of dust remover box body
Figure FDA0002489688270000014
The method comprises the following steps:
the method comprises the following steps: determining the torsion slenderness ratio lambda of the H-shaped steel upright postzWeb height H of H-shaped steel column0Web thickness t of H-shaped steel columnwWidth B of flange of H-section steel column and thickness t of flange of H-section steel columnfWall thickness t of wall panelwallSaid λzDimensionless, said h0、tw、B、tf、twallAll in mm;
step two: obtaining the axial pressure stability coefficient of the upright post of the dust remover box body according to the following formula (2)
Figure FDA0002489688270000015
Figure FDA0002489688270000016
2. The method for determining the axial pressure stable bearing capacity of the upright post of the dust remover box body as claimed in claim 1, wherein the calculation analysis shows that the welding residual stress between the wall plate and the upright post has no adverse effect on the axial pressure stability of the upright post, and the influence of the residual stress and the residual deformation does not need to be considered and embodied in the calculation.
3. The method for determining the axial pressure stabilizing bearing capacity of the upright post of the dust catcher box as claimed in claim 1, wherein the structure of the dust catcher box is as follows: the wall plate of the dust remover box body is a steel plate with stiffening ribs, the wall plate is continuously welded with the flange on one side of the upright column, the upright column is hot-rolled H-shaped steel, and the dust remover box body is internally supported in the upright column in the direction of the vertical wall plate at equal intervals.
4. The method for determining the axial pressure stabilizing bearing capacity of a column of a dust collector box body as claimed in claim 1, wherein the wall thickness t of the wall platewallIs 4-10 mm; torsion slenderness ratio lambda of H-shaped steel upright postz56-138, the flange width-thickness ratio B/tf6.4-23.6, and the height-thickness ratio h of web plate0/tw15-58.8, the ratio t of the wall thickness of the wall plate to the thickness of the flangewall/tfIs 0.4-0.75.
5. The method for determining the axial pressure stable bearing capacity of the upright post of the dust collector box body as claimed in claim 1, wherein the influence of the initial geometric defects of the wallboard-upright post structural system and the residual stress generated in the welding process of the wallboard and the upright post is considered, and the welding residual stress and the residual deformation and the wallboard wall thickness t are consideredwallWidth w of stiffening wallboard, stiffness of stiffening rib, spacing of stiffening rib, connecting plate and transverse supporting spacing l0The bending slenderness ratio lambda of the upright column around the y-y axis of the section symmetry axisyWall plate wall thickness to flange thickness ratio twall/tfCross-sectional torsional slenderness ratio lambdazHeight-thickness ratio h of cross-section web0/twFlange width-thickness ratio B/t of cross sectionfAnd quantitatively researching the influence rule of the stable bearing capacity of the box body upright column, and obtaining an upright column axial pressure stable bearing capacity calculation formula represented by the geometric parameters of the multi-item structure by utilizing least square fitting.
6. The method for determining the axial pressure stable bearing capacity of the upright post of the dust catcher as claimed in claim 1, wherein the calculated axial pressure stable bearing capacity of the upright post of the dust catcher box has a relative error of 3.2% on average with the stable limit bearing capacity calculated by finite element.
7. Use of a method for determining the axial pressure stability bearing capacity of a column of a dust catcher box as claimed in any one of claims 1 to 6 in the analysis of the structural stability performance of the dust catcher box.
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