CN113553649A - Method for determining rigidity characteristic of steel structure pin shaft node - Google Patents
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Abstract
The invention relates to a method for determining rigidity characteristics of a steel structure pin shaft node, which comprises the following steps: determining the size design parameters of the pin roll node based on the pin roll and lug plate structure regulation in the pin roll node, the actual bending moment, the actual tensile force design value and the actual material strength design value of the project; performing preliminary geometric modeling on each component including the pin shaft and the lug plate in the pin shaft node based on finite element analysis software; carrying out grid division on the components of the pin roll node model based on the hexahedron unit type; establishing the relationship among the components by setting the interaction among the components of the pin roll node; the displacement and the bending moment of different pin roll nodes are obtained by applying beam end vertical load and column top load to the pin roll nodes; calculating the pin roll node corner, and drawing a pin roll node bending moment-corner curve; and extracting the first derivative of the curve to obtain the initial rotational rigidity of the pin roll node. The influence of the change of the rigidity characteristic of the pin roll node on the response of the structure such as displacement and the like is better reflected.
Description
Technical Field
The invention belongs to the technical field of civil engineering, and particularly relates to a method for determining rigidity characteristics of a steel structure pin shaft node.
Background
For steel structure buildings, particularly airports and public buildings, the pin shaft joint connection mode is widely applied. In a large steel structure building, node connection is complex, the precondition assumption of a node calculation method in specifications cannot be applied to all situations, particularly in an elastic stage, pin shaft nodes in a macroscopic model are assumed to be hinged, but few nodes are completely rigid connection or completely hinged connection, so that the assumption often causes the calculation result to be seriously deviated from the actual situation.
The structural rod piece of the pin shaft hinged joint can rotate around the center of the pin shaft and only can transmit axial force, so that the pin shaft joint is hinged in the direction, but has semi-rigidity characteristic in other directions. And test results show that most of nodes in practical engineering belong to semi-rigid nodes, and the design of a steel frame is designed according to the semi-rigid nodes in practice so as to ensure that the nodes are closer to the real condition of the structure. Based on the research of domestic and foreign scholars on steel structure and the demonstration of a large number of practical projects, the node forms of bolt connection, welding, angle steel connection and the like in beam-column connection in the structure are not completely rigid connection or completely hinged, but are connection nodes with semi-rigid characteristics. In actual engineering, ideal rigid nodes and hinge points do not exist. Therefore, semi-rigid node modeling is provided for the pin shaft connecting node, and the influence of different connecting modes, different connecting rigidity and different node sizes on the structural response is discussed.
At present, the simulation analysis technology for the construction process is becoming wide, but the technology still exists: in the construction process, the deformation and stress change of the key rod piece are difficult to obtain directly, and the requirement of structural safety monitoring in the construction process cannot be met; if the microscopic scale model is adopted to carry out detailed modeling on different construction sections of the structure, the complex structure can greatly increase the modeling time and reduce the calculation efficiency, and a lot of unnecessary structural response analysis can be generated, so that the safety of the structure in the construction process is difficult to judge in real time. Therefore, how to improve the monitoring comprehensiveness and improve the component installation accuracy and modeling efficiency has become a technical problem to be solved urgently by those skilled in the art.
Disclosure of Invention
In order to solve the problems of low component installation precision and low modeling efficiency in the prior art, the invention provides a method for determining the rigidity characteristic of a steel structure pin shaft node, which has the characteristics of better reflecting the influence of the change of the rigidity characteristic of the pin shaft node on the response of the structure such as displacement and the like, enabling the component to be installed more accurately, having higher modeling efficiency and the like.
According to the specific embodiment of the invention, the method for determining the rigidity characteristic of the steel structure pin shaft node comprises the following steps:
determining the size design parameters of the pin roll node based on the pin roll and lug plate structure regulation in the pin roll node, the actual bending moment, the actual tensile force design value and the actual material strength design value of the project;
performing preliminary geometric modeling on each component including the pin shaft and the lug plate in the pin shaft node based on finite element analysis software;
carrying out grid division on the components of the pin roll node model based on the hexahedron unit type;
establishing the relationship among the components by setting the interaction among the components of the pin roll node;
the displacement and the bending moment of different pin roll nodes are obtained by applying beam end vertical load and column top load to the pin roll nodes;
calculating the pin roll node corner by using a deflection method and a relative deformation method based on the displacement and the bending moment, and drawing a pin roll node bending moment-corner curve;
and extracting a first derivative of the curve to obtain the initial rotational rigidity of the pin roll node based on the bending moment-corner curve of the pin roll node.
Further, the determining of the size design parameters of the pin roll node based on the pin roll and lug plate construction regulations, the actual bending moment of the engineering, the design value of the tensile force and the design value of the material strength in the pin roll node comprises:
and based on the stress characteristic of the pin roll node, selecting the end distance of the lug plate and the edge distance of the lug plate, and analyzing the parameters of the steel structure pin roll node by taking the diameter of the pin roll and the thickness of the lug plate as main parameters influencing the rigidity performance of the node.
Further, the preliminary geometric modeling of the pin roll nodes including the pin roll and the lug plate by the eight-node reduction integration unit in the finite element analysis software includes:
preliminary geometric modeling was performed based on ABAQUS software.
Further, the establishing of the relationship among the components by setting the interaction among the components of the pin joint comprises:
based on the contact between the connecting plate and the lug plate, the contact between the pin shaft and the hole wall of the lug plate, and the contact between the gasket and the surface of the lug plate, when the contact surfaces between the setting parts touch each other, the contact constraint is directly activated to establish the relationship including normal relationship, friction, coupling and binding.
Further, the pin node model adopts constraints as binding and coupling type constraints.
The invention has the beneficial effects that: determining the size design parameters of the pin shaft node based on the pin shaft and lug plate structure regulation, the actual bending moment of engineering, the tensile force design value and the material strength design value in the pin shaft node by considering the influence of the node rigidity on the structural rod member deformation; performing preliminary geometric modeling on all components including a pin shaft and an ear plate in a pin shaft node based on an eight-node reduction integral unit in finite element analysis software; carrying out grid division on the components of the pin roll node model based on the hexahedron unit type; establishing the relationship among the components by setting the interaction among the components of the pin roll node; the displacement and the bending moment of different pin roll nodes are obtained by applying beam end vertical load and column top load to the pin roll nodes; calculating a pin roll node corner by using a deflection method and a relative deformation method based on displacement and bending moment, and drawing a pin roll node bending moment-corner curve; and extracting a first derivative of the curve to obtain the initial rotational rigidity of the pin roll node based on the bending moment-corner curve of the pin roll node. Therefore, the influence of the change of the rigidity characteristic of the pin shaft node on the response of the structure such as displacement and the like can be better reflected, the installation precision of the component can be further improved, and the modeling efficiency and the monitoring comprehensiveness can be improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a flowchart of a method for determining rigidity characteristics of a steel structure pin node according to an exemplary embodiment;
FIG. 2 is a schematic illustration of the pin and lug dimensions provided in accordance with an exemplary embodiment;
FIG. 3 is a 3D model of a modeled beam provided in accordance with an exemplary embodiment;
FIG. 4 is a 3D model of a modeled column provided in accordance with an exemplary embodiment;
FIG. 5 is a 3D model of a main otic placode of a created model provided in accordance with an exemplary embodiment;
FIG. 6 is a 3D model of a stiffener of the built model provided in accordance with an exemplary embodiment;
FIG. 7 is a 3D model of a dome sheet of a created model provided in accordance with an exemplary embodiment;
FIG. 8 is a pin node meshing provided in accordance with an exemplary embodiment;
FIG. 9 is an ear plate meshing provided in accordance with an exemplary embodiment;
FIG. 10 is a connection plate meshing provided in accordance with an exemplary embodiment;
FIG. 11 is a beam grid partitioning provided in accordance with an exemplary embodiment;
FIG. 12 is a pin node model meshing provided in accordance with an exemplary embodiment;
FIG. 14 is a top view of a pin node provided in accordance with an exemplary embodiment;
FIG. 15 is a schematic illustration of displacements U2, U3 provided in accordance with an exemplary embodiment;
FIG. 13 is a semi-rigid connection three-parameter model curve provided in accordance with an exemplary embodiment.
Reference numerals
1-first secondary ear panel; 2-second secondary ear plate; 3-a first beam; 4-second beam.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.
The change of the rigidity characteristic of the pin shaft node influences the response of the structure such as displacement and the like, and further influences the mounting position precision of the component. In the traditional structure design process, a pin roll node is regarded as a hinged node, but in an actual structure, a structural rod piece of the pin roll hinged node can rotate around the center of a pin roll and only can transmit axial force, so the pin roll node is hinged in the direction, but the node in other directions generally has semi-rigid characteristics, and the designed result is different from the structural analysis result of construction and use of the actual structure, so that as shown in fig. 1, the embodiment of the invention provides a method for determining the rigidity characteristic of the steel structure pin roll node, which specifically comprises the following steps:
101. determining the size design parameters of the pin roll node based on the pin roll and lug plate structure regulation in the pin roll node, the actual bending moment, the actual tensile force design value and the actual material strength design value of the project;
102. performing preliminary geometric modeling on each component including the pin shaft and the lug plate in the pin shaft node based on finite element analysis software;
103. carrying out grid division on the components of the pin roll node model based on the hexahedron unit type;
104. establishing the relationship among the components by setting the interaction among the components of the pin roll node;
105. the displacement and the bending moment of different pin roll nodes are obtained by applying beam end vertical load and column top load to the pin roll nodes;
106. calculating a pin roll node corner by using a deflection method and a relative deformation method based on displacement and bending moment, and drawing a pin roll node bending moment-corner curve;
107. and extracting a first derivative of the curve to obtain the initial rotational rigidity of the pin roll node based on the bending moment-corner curve of the pin roll node.
Therefore, the structural size of the pin roll node is determined, a pin roll node model is established by adopting a node microscopic scale model modeling method, a node corner is extracted based on a relative deformation method and a deflection method, errors of the corners obtained by the two methods are contrastively analyzed, a node bending moment-corner curve is drawn, and the initial rigidity of the node is determined according to the first-order derivative of the bending moment-corner curve in the elastic stage.
Firstly, the diameter of a pin shaft, the diameter of a hole wall, the size of an ear plate and the specific position distribution of each part are calculated and determined by combining the design specification of a steel structure (GB 50017-2017); secondly, the grids of different parts of the nodes are divided differently, and all parts need to adopt structured grid division; moreover, as the ABAQUS does not directly identify that the two mutually contacting entities or assemblies in the model have a contact relationship, the contact and constraint between the components need to be represented by setting the interaction between the components, and the contact model establishes the normal relationship and friction between the components, and the constraint defines the coupling and binding relationships between the components; finally, the main problem of semi-rigid joint connection is the rotation angle of the joint, and because the joint has certain rigidity, how to determine the deformation of the joint is important in the process of bending moment transmission.
As a feasible implementation manner of the embodiment, the pin roll node mainly comprises a main lug plate, a secondary lug plate and a pin roll, and according to the stress characteristic of the node, the lug plate end distance a, the lug plate edge distance c, the pin roll diameter d and the lug plate thickness t are selected as main parameters influencing the rigidity performance of the node, so that the parameter analysis of the steel structure pin roll node is performed. The specific meaning of each symbol is shown in the ear plate schematic diagram, namely figure 2.
Firstly, determining the construction size of a pin roll node according to the pin roll and lug plate styles and construction regulations thereof: according to the design Specification of Steel Structure (GB 50017-2017), the bending strength of the pin shaft can be calculated according to the following formula:
in the formula, b is the bending stress of the cross section of the pin shaft, and the unit is MPa; m is a design value of the bending moment of the cross section calculated by the pin shaft, and the unit is N.mm; f. ofbThe bending strength of the pin shaft is designed value and is expressed in MPa.
The bending moment calculated on the cross section of the pin shaft can be determined by calculation according to the following formula:
in the formula, t1、t2C means as shown in the ear plate schematic in FIG. 2;
the shear strength checking calculation of the pin shaft can be determined according to the following calculation formula:
in the formula, τbThe unit is the shearing stress of the cross section of the pin shaft and is MPa; n is a tensile force design value and is in the unit of N; d is the diameter of the pin shaft, nvFor typical pin connections, n is the number of faces to be shearedv＝2；
The shear strength is designed value of the pin shaft and is expressed in MPa.
When the pin shaft is subjected to the bending shearing action, the pin shaft can be calculated and determined according to a combined strength formula:
the bearing strength of the pin shaft and the lug plate can be determined by the following calculation, and if the materials of the pin shaft and the lug plate are different, the material with low strength is selected for checking calculation.
In the formula, σcThe extrusion stress of the pin shaft to the lug plate is expressed in MPa; t is the thickness of the ear plate in mm;
the design value of the bearing strength of the pin hole wall of the lug plate is in MPa.
According to the structural design specifications of railway bridge steel, the net section tensile strength and the end part tensile strength of the lug plate are calculated and determined according to the following formulas:
in the formula I1、l2As shown in the schematic view of the ear plate of FIG. 2; f is the design value of the tensile strength of the lug plate and is expressed in MPa.
The shear strength of the end of the ear plate can be verified according to the following formula:
wherein tau is the section shearing stress of the end part of the ear plate and has the unit of MPa; fv is the shear strength design value of the otic placode steel, and the unit is MPa.
The pin and lug structure is defined as follows:
ear plate thickness specification: too small a thickness of the ear plate results in a bearing capacity of the ear plate, and thus the thickness of the ear plate needs to be controlled. Because the otic placode divide into main otic placode and inferior otic placode, and main otic placode is generally thicker than inferior otic placode, so refer to foreign relevant standard, confirm that inferior otic placode thickness should satisfy the formula:
the gap requirement between the pin shaft and the pin hole is as follows: according to the research on the contact stress of the pin shaft, the size of the gap between the pin shaft and the pin hole influences the contact stress of the pin shaft, so that the difference between the pin shaft aperture and the pin shaft diameter is required to be less than or equal to 1mm in the design specification of a steel structure.
Length regulation of the pin shaft: the length of the pin shaft should exceed the outer side surface of the secondary lug plate by more than 6mm so as to ensure the normal installation of the limiting bolt.
Determining the material of the pin shaft node: the pin shaft is made of 40Cr steel, and the ear plate is made of Q345 steel.
And calculating and determining the structural size of the pin shaft node, firstly determining the design value N of the tensile force as 1000KN and the thickness t of the main lug plate1Thickness t of sub-otic placode2And taking the distance between the pin shaft and the hole wall as 0.1mm, and then calculating and determining the diameter of the pin shaft, the diameter of the hole wall, the size of the lug plate and the specific position distribution of each part. The 3D model of the beam of the built model is shown in fig. 3, the 3D model of the post is shown in fig. 4, the 3D model of the main ear plate is shown in fig. 5, the 3D model of the stiffener is shown in fig. 6, and the 3D model of the dome plate is shown in fig. 7.
Then, selecting a modeling material, establishing a constitutive relation according to data obtained by a material test, and respectively giving stress-strain curves of Q345-grade steel and a bolt by adopting a trilinear vibration strengthening model. Wherein, the pin shaft is made of alloy steel Cr 40. According to the specification, the poisson ratio mu of the steel Q345 is 0.3. E2.1 × 10 of Cr40 steel5MPa. Then, the element type and the mesh of the entity model are divided, and the selection of the element type in the finite element calculation has larger influence on the precision of the simulation analysis result. The finite element analysis software ABAQUS has 8 types of units, wherein according to a large amount of simulation researches, the fact that the contact condition of each part of a node can be well simulated by adopting an eight-node reduction integration unit (C3D8R) in a solid unit is found, the simulation analysis result error of node displacement is small, and the influence of the deformation of a grid in the analysis process on the accuracy of a model analysis result is small. Therefore, an eight-node reduction integral unit is selected to perform solid unit simulation on the components such as the lug plate, the stiffening rib and the like. Eight node reduction productThe hexahedron partitioning unit or the tetrahedron partitioning unit can be adopted when the cell partitioning type is used for grid partitioning, and the hexahedron cell type is selected as a component of the model to partition the grid because the node model is regular in size and has a high requirement on the precision of a simulation analysis result. Since the thickness of the beams and the columns is less than 1/10 of the overall structure size, shell units in the structural units are adopted, so that the calculation is simple, and a three-dimensional solid continuous unit can be simulated approximately, wherein the unit type is SC 8R.
The meshing precision of each component is shown in the following table:
the corresponding pin node meshing is shown in fig. 8, the ear plate meshing is shown in fig. 9, the connecting plate meshing is shown in fig. 10, the beam meshing is shown in fig. 11, and the pin node model meshing is shown in fig. 12.
Since the ABAQUS does not directly recognize that there is a contact relationship between two mutually contacting entities or assemblies in the model. In some cases, the contact surfaces of the two entities only transmit forces perpendicular to the contact surfaces. When friction exists between two physical surfaces, it is necessary to indicate contact and constraint between the components by setting the interaction between the components. The contact model establishes normal relationships, friction, between the components. Constraints define relationships such as couplings and bindings between components.
Contacting: in the bolt node model, a friction coefficient of 0.20 is taken for a contact unit between the pin shaft and the plate. The friction coefficient between the pin shaft and the hole wall is 0.15. The contact mainly comprises: the contact between the connecting plate and the lug plate, the contact between the pin shaft and the hole wall of the lug plate, and the contact between the gasket and the surface of the lug plate. The contact constraint is directly activated when the contact surfaces between the setting members touch each other.
And (3) constraint: the pin roll node model adopts constraint as binding and coupling type constraint.
Binding and constraining: binding constraints connect two surfaces into a whole, keeping the same motion. In the model, binding constraints are defined between beams and columns, between pin shafts and lug plates, between beams and circular cover plates.
Coupling constraint: the coupling constraint is to define a reference point, couple the reference point with the region to be constrained, so that the stress characteristics of the region are evenly distributed in the recoupling surface. In the model, coupling constraint is applied to the column top and the beam end, so that the concentrated load of the column top and the vertical load of the beam end are uniformly distributed on a stress surface.
Boundary conditions and loading modes: in the model, consolidation constraint is applied to the column bottom, and the out-of-plane degree of freedom of the beam end is constrained in the load application analysis step, so that contact is stably applied, and the model calculation convergence is facilitated. The loading mode is that a vertical concentrated load is arranged at the top of the column, and a vertical load, an axial load and a bending moment are arranged at the beam end.
Creating an analysis step and setting output variables: the whole analysis process of the model is divided into three analysis steps, wherein the first step is an initial analysis step which is used for defining the boundary conditions of the model. The second step is to apply a concentrated load to the top of the column and the third step is to apply a vertical load to the beam ends.
Then, after a microscopic scale model of the pin roll node is built, a beam end vertical load and a column top load F are appliedL1、M、Fz1And obtaining displacement and bending moment of different node sets under the load.
And grid nodes at the tail ends of the secondary ear plate 1 and the secondary ear plate 2 are set as node sets U1 and U2. The grid nodes at the tail ends of the main ear plates are set to be node sets U3 and U4. The pin roll node extracts the change data of the horizontal displacement of each node and the section bending moment of the node along with the time step, and if the total time step is t and the number of nodes in a node set is n:
U1x＝[U11x U12x U13x...U1nx]
U2x＝[U21x U22x U23x...U2nx]
U3x＝[U31x U32x U33x...U3nx]
U4x＝[U41x U42x U43x...U4nx]
M1x＝[M11x M12x M13x...M1tx]
M2x＝[M21x M22x M23x...M2nx]
M3x＝[M21x M22x M23x...M2tx]
M4x＝[M41x M42x M43x...M4tx]
when steel structure modeling design is carried out, steel structure modeling and calculation are generally carried out in an elastic range, and at the moment, the bending moment and the corner of the node are in a linear relation, so that the rigidity characteristic of the node can be represented by adopting a first derivative of a bending moment corner curve. The following formula:
the current general method for describing the M-theta curve of the node is to fit experimentally obtained bending moment and corner data of the node by a simple function expression. A three-parameter model suitable for structural analysis is adopted, and the formula expression is as follows:
in the formula, RkiIs the initial stiffness of the nodal connection, θ0＝Mu/Rki，MuTo limit the bending load capacity, n is the form factor related to the initial stiffness of the connection. The specific meaning is shown in figure 15.
The main problem of semi-rigid joint connection is the rotation angle of the joint, and because the joint has certain rigidity, a corner appears in a joint area in the process of bending moment transmission, usually a bending moment-corner characteristic curve standard is adopted, but the current steel structure specification generally regards the joint as a hinged joint or a rigid joint directly, and the specific calculation mode of the bending moment and the corner of the joint is not described in the current steel structure design standard. A large number of tests prove that the node is not completely rigid or hinged in actual engineering and generally shows semi-rigid characteristics, and transmits bending moment and shearing force of parts. Therefore, in order to explore the initial rotational stiffness of the node, the deformation of the node needs to be determined first.
The deformation of the node is composed of a node domain and a connecting node, so that the shearing deformation of the node and the deformation of a node member need to be considered when the node corner is calculated. The calculation method of the node deformation in the elastic stage comprises a deflection method and a relative deformation method.
A deflection method comprises the following steps: the deflection method is that under the ideal state, the deflection caused by bending deformation is subtracted from the deflection value of a certain point on a beam to obtain the deflection value generated by node domain deformation and connecting part deformation, so that the node corner is calculated as follows:
in the formula: l is the distance from the selected beam upper measuring point to the column axis;
V1the ideal deflection of the beam is obtained by calculating by using a material mechanics cantilever beam deflection curve formula;
V2node domain deformation and connecting portion deformation.
Relative deformation method: the size of the corner of the node is represented by the relative corner change value between the beam column, namely:
in the formula:
-beam corners;
The columns are connected with the nodes through beams, and the upper ends and the lower ends of the columns are fixedly bound, so that the column corner of the proposed node model is almost zero and is ignored. The node area is divided into a tension zone and a compression zone. The tension area is the tension of the pin shaft, the upper part of the lug plate in the node area is in tension, the upper part of the beam end is in tension, and the compression area is the compression of the lower part of the lug plate in the node area and the compression of the lower part of the beam end. And analyzing the node structure of the model, wherein the rotation deformation of the node connection is concentrated on the intersection point of the lug plate and the beam. The corner of the node is the corner of the intersection point of the node plate and the beam 1.
Comparing the two methods, the relative deformation method can be adopted without calculating the beam deformation, the upper horizontal displacement and the bottom horizontal displacement of the intersection point of the gusset plate and the beam are directly extracted from the calculation result to calculate the node corner, the bending moment is extracted according to the time step, so that a node bending moment-corner curve is obtained, and the node bending moment-corner curve is utilized
And obtaining the initial connection rigidity of the node.
And outputting the bending moment M of the centers of the intersection points of the first beam 3, the second beam 4 and the secondary lug plate according to the model calculation result. And the horizontal displacement U1 of the tail end of the first lug plate 1, the horizontal displacement U2 of the tail end of the second lug plate 2, the horizontal displacement U3 of the tail end of the lug plate and the pin joint in the joint area are shown in the figure 13, and the displacement U2 and U3 are schematically shown in the figure 14.
If the structural material is a linear elastic material, the deformation generated under the action of the bending moment is very small, namely, the deformation is in an elastic deformation stage, and then the corner deformation of the node is as follows:
θ1＝(U1-U3)/hf
θ2＝(U2-U3)/hf
the initial stiffness of the node is the stiffness when the bending moment and the corner curve are linear, and can be written as:
K1＝M1/θ1
K2＝M2/θ2
K＝(K1+K2)/2
according to the ABAQUS calculation result, extracting the horizontal displacement of the grid node sets U1 and U2 at the tail ends of the first-time ear plate 1 and the second-time ear plate 2, extracting the horizontal displacement of the grid node sets U3 and U4 at the tail ends of the ear plates, calculating the node rotation angle according to a relative deformation method, drawing a node bending moment-rotation angle curve, and extracting a first derivative of the curve as node rigidity according to the node bending moment-rotation angle curve.
According to the embodiment of the invention, by considering the influence of the node rigidity on the deformation of the structural member, the method for microscale modeling and rigidity characteristic determination of the steel structure pin shaft node is provided, the method for extracting the corner-bending moment curve of the pin shaft node is determined, the calculation method of the initial rotational rigidity of the node is provided, the influence of the change of the rigidity characteristic of the pin shaft node on the response of the structure such as displacement and the like can be better reflected, the mounting precision of the component is improved, and the modeling efficiency and the monitoring comprehensiveness are improved.
It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and when the program is executed, the program includes one or a combination of the steps of the method embodiments.
In addition, functional units in the embodiments of the present invention may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.
The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the embodiments described herein are intended to embrace all such alterations, modifications and variations that fall within the scope of the appended claims. Furthermore, to the extent that the term "includes" is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim. Furthermore, any use of the term "or" in the specification of the claims is intended to mean a "non-exclusive or".
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (5)
1. The method for determining the rigidity characteristic of the steel structure pin shaft node is characterized by comprising the following steps of:
determining the size design parameters of the pin roll node based on the pin roll and lug plate structure regulation in the pin roll node, the actual bending moment, the actual tensile force design value and the actual material strength design value of the project;
performing preliminary geometric modeling on each component including the pin shaft and the lug plate in the pin shaft node based on finite element analysis software;
carrying out grid division on the components of the pin roll node model based on the hexahedron unit type;
establishing the relationship among the components by setting the interaction among the components of the pin roll node;
the displacement and the bending moment of different pin roll nodes are obtained by applying beam end vertical load and column top load to the pin roll nodes;
calculating the pin roll node corner by using a deflection method and a relative deformation method based on the displacement and the bending moment, and drawing a pin roll node bending moment-corner curve;
and extracting a first derivative of the curve to obtain the initial rotational rigidity of the pin roll node based on the bending moment-corner curve of the pin roll node.
2. The method for determining the rigidity characteristic of the steel structure pin shaft node according to claim 1, wherein the step of determining the size design parameters of the pin shaft node based on the pin shaft and lug plate structure regulation, the actual bending moment of engineering, the design value of tensile force and the design value of material strength in the pin shaft node comprises the following steps:
and based on the stress characteristic of the pin roll node, selecting the end distance of the lug plate and the edge distance of the lug plate, and analyzing the parameters of the steel structure pin roll node by taking the diameter of the pin roll and the thickness of the lug plate as main parameters influencing the rigidity performance of the node.
3. The method for determining the rigidity characteristic of the steel structure pin shaft node according to claim 1, wherein the preliminary geometric modeling of the pin shaft node including the pin shaft and the lug plate on the basis of an eight-node reduction integration unit in finite element analysis software comprises:
preliminary geometric modeling was performed based on ABAQUS software.
4. The method for determining the rigidity characteristic of the steel structure pin node according to claim 1, wherein the establishing of the relationship among the components by setting the interaction among the components of the pin node comprises:
based on the contact between the connecting plate and the lug plate, the contact between the pin shaft and the hole wall of the lug plate, and the contact between the gasket and the surface of the lug plate, when the contact surfaces between the setting parts touch each other, the contact constraint is directly activated to establish the relationship including normal relationship, friction, coupling and binding.
5. The method for determining rigidity characteristics of the steel structure pin node according to claim 4, wherein the pin node model adopts constraints of binding and coupling types.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115981255A (en) * | 2022-12-12 | 2023-04-18 | 江苏丰华建筑系统集成有限公司 | Performance monitoring method and system of steel structure test platform |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018039717A1 (en) * | 2016-08-31 | 2018-03-08 | Monash University | Connection arrangement for connecting a cross-member to a vertical member |
| CN109815529A (en) * | 2018-12-13 | 2019-05-28 | 重庆顺泰铁塔制造有限公司 | Angle steel-gusset plate connecting node design method |
-
2021
- 2021-07-26 CN CN202110844452.8A patent/CN113553649A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018039717A1 (en) * | 2016-08-31 | 2018-03-08 | Monash University | Connection arrangement for connecting a cross-member to a vertical member |
| CN109815529A (en) * | 2018-12-13 | 2019-05-28 | 重庆顺泰铁塔制造有限公司 | Angle steel-gusset plate connecting node design method |
Non-Patent Citations (3)
| Title |
|---|
| ALEMDAR F 等: "Moment-rotation characteristics and finite element analysis of cold formed steel connections", ULUDAĞ ÜNIVERSITESI MÜHENDISLIK FAKÜLTESI DERGISI, vol. 26, no. 1, 18 January 2021 (2021-01-18), pages 29 - 46 * |
| 王伟 等: "上海光源工程屋盖钢管节点平面外受弯性能试验研究", 建筑结构学报, vol. 30, no. 01, 28 February 2009 (2009-02-28), pages 75 - 81 * |
| 禹海涛 等: "长大隧道地震响应分析与试验方法新进展", 中国公路学报, vol. 31, no. 10, 31 October 2018 (2018-10-31), pages 19 - 35 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115981255A (en) * | 2022-12-12 | 2023-04-18 | 江苏丰华建筑系统集成有限公司 | Performance monitoring method and system of steel structure test platform |
| CN115981255B (en) * | 2022-12-12 | 2023-12-15 | 扬州丰筑建设工程有限公司 | Performance monitoring method and system for steel structure test platform |
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