CN108413860B - A kind of method of real-time of silent section thin walled beam constrained twisting deformability - Google Patents
A kind of method of real-time of silent section thin walled beam constrained twisting deformability Download PDFInfo
- Publication number
- CN108413860B CN108413860B CN201810088878.3A CN201810088878A CN108413860B CN 108413860 B CN108413860 B CN 108413860B CN 201810088878 A CN201810088878 A CN 201810088878A CN 108413860 B CN108413860 B CN 108413860B
- Authority
- CN
- China
- Prior art keywords
- section
- strain
- measuring
- point
- measurement
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 24
- 238000005259 measurement Methods 0.000 claims abstract description 34
- 238000006073 displacement reaction Methods 0.000 claims abstract description 28
- 238000012544 monitoring process Methods 0.000 claims abstract description 17
- 238000004364 calculation method Methods 0.000 claims abstract description 8
- 238000010008 shearing Methods 0.000 claims description 3
- 239000000835 fiber Substances 0.000 description 2
- 230000006399 behavior Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
- G01B7/18—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in resistance
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
The invention discloses a kind of method of real-time of silent section thin walled beam constrained twisting deformability, this method measures the axial strain of beam by using strain transducer, the warp displacement and windup-degree of beam arbitrary section can be obtained using theoretical method, it realizes the real-time monitoring of structural constraint torsional deflection, reduces the time of the silent section thin walled beam constrained twisting deformability of real-time monitoring.This method facilitates the Accurate Reconstruction of structural stress strain state, and further work provides shape monitoring data for planform control etc..The present invention proposes the specific embodiment based on limited element calculation model to verify accuracy of the invention.The present invention has many advantages, such as precision height, saves time and cost, is high-efficient compared with the method for other measurement beam constrained twisting deformabilities at present.
Description
Technical Field
The invention relates to the technical field of real-time monitoring of closed-section thin-wall beam constrained torsional deformation in the fields of aerospace, civil engineering, bridges and the like, in particular to a real-time monitoring method of closed-section thin-wall beam constrained torsional deformation.
Background
In the engineering field, the torsion of the closed thin-wall beam is easy to bring catastrophic results such as structural instability and damage. The structural constraint torsional deformation comprises complex behaviors such as section warping and the like, and is difficult to predict accurately. Conventional resistive strain gauge sensors and advanced fiber sensors (e.g., Fiber Bragg Gratings (FBGs), distributed fibers) can measure the surface strain of a structure, and then reconstruct the structure shape according to the surface strain. At present, a method for calculating the torsional deformation by directly utilizing the quantitative relation between the surface strain and the torsional deformation of the structure is lacked. The main torsional deformation comprises a section torsional angle and a section buckling displacement, the conventional measuring method has complicated steps and complicated equipment when measuring the torsional angle, and cannot complete online monitoring, and on the other hand, a method capable of accurately monitoring the section buckling displacement is lacked.
Disclosure of Invention
According to the problems in the prior art, the invention discloses a real-time monitoring method for constrained torsional deformation of a closed-section thin-wall beam, which comprises the following specific steps: the method comprises the steps of selecting a strain measurement point on the surface of the closed section thin-wall beam along the axial direction, pasting a strain sensor on the strain measurement point, measuring the axial strain in real time, calculating the sector area of the section of the closed section thin-wall beam, and deducing the torsion angle and the warping displacement of each cross section through the strain measurement value and the sector area, thereby monitoring the torsion deformation of the closed section thin-wall beam in real time.
The cross section torsion angle and the buckling displacement of the closed section thin-wall beam are calculated in the following mode:
s1: calculating the distribution of the sector area omega(s) of the section of the thin-wall beam:
wherein s is the curve coordinate of the measuring point on the section outline, h(s) is the distance from the rotation center to the tangent of the s point,for the shearing redundancy, the calculation method comprises the following steps:
wherein J is the free torsional moment of inertia, t is the wall thickness, AmIs the closed cross-sectional area;
s2: dividing the beam into a plurality of measuring sections along the axial direction, wherein the length of each measuring section is equal;
s3: at the end point of each measuring section, the measuring point of the strain sensor is arranged on the surface of the beam, and the position of the measuring point is x0，x1，x2，…xnWhere n +1 is the number of measurement points, x0At one end of the beam, xnAt the other end of the beam, with the other measurement point at x0And xnBetweenArranging in sequence; x is the number of1To xnArranged on a straight line parallel to the beam axis; on the beam section, the coordinate of the outline corresponding to the measuring point is sm；
In the measuring section [ x ]i-1,xi]Above, the strain expression is:
wherein epsiloni-1And εiIs xi-1And xiThe strain measurement at (a), the x-direction being the beam axis direction;
s4: the relationship between the surface strain and the torsion angle is obtained as follows:
wherein,is the torsion angle, ω(s)m) Is the cross-sectional sector area at the measurement point;
s5: obtaining a relation between the section warping displacement and the strain as follows:
u(x)＝∫ε(x)dx(5)
s6: and (3) deducing a warping displacement calculation formula of any section and any position on the section by combining the formulas (1), (2), (3) and (5):
wherein u isiIs xiIs the warp displacement,. DELTA.l is the distance between the measuring points,. epsilonj-1And εjIs xj-1And xjMeasured value of strain of (u)0Is x0Warp displacement of (c) for a clamped beam at one end, u0＝0；
S7: based on equation (4), in the measurement section [ x ]i-1,xi]Above, there are
S8: combining the formulas (1), (2), (3) and (7) to obtain xiThe twist angle of (d) is:
where Δ l is the distance between the measuring points, ω(s) is the sector area of the measuring location, ε0，εiAnd εjIs x0，xiAnd xjThe measured value of the strain at (a),and u0Is x0Torsion angle and warp displacement of the beam, for a clamped beam at one end
By adopting the technical scheme, the method for monitoring the restrained torsional deformation of the closed-section thin-wall beam provided by the invention has the advantages that the axial strain of the beam is measured by adopting the strain sensor, the warp displacement and the torsion angle of any section of the beam can be obtained by applying a theoretical method, the real-time monitoring of the structure restrained torsional deformation is realized, and the time for monitoring the restrained torsional deformation of the closed-section thin-wall beam in real time is reduced. The method facilitates accurate reconstruction of the stress-strain state of the structure and provides shape monitoring data for further work such as structure shape control. The invention proposes a specific implementation based on finite element calculation models to verify the accuracy of the invention. Compared with other methods for measuring beam constrained torsional deformation at present, the method has the advantages of high precision, time and cost saving, high efficiency and the like.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be 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 described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic diagram of a rectangular closed-section thin-wall beam and a strain measurement position
FIG. 2 is a schematic cross-sectional view of a rectangular closed section thin-walled beam;
FIG. 3 is a comparison of cross-sectional warp displacements and finite element results calculated by the method of the present invention;
FIG. 4 is a comparison of cross-sectional warp displacement and finite element results calculated by the method of the present invention;
FIG. 5 is a comparison of cross-sectional torsion angles calculated by the method of the present invention and finite element results.
In the figure, 1, a thin-wall beam with a rectangular cross section; 2. strain measurement point positions; 3. the line where the strain measurement point is (parallel to the axial direction, the line is not limited to the one drawn in the figure, as long as the line is parallel to the axis on the surface of the beam); 4. strain measurement point spacing; 6-7, cross section symmetry axis; 8. the corresponding position of the strain measurement point on the cross section can be any, and the position of the strain measurement point is not limited to the position drawn in the figure, and mainly depends on the position of the straight line where the strain measurement point in 3 is located.
Detailed Description
In order to make the technical solutions and advantages of the present invention clearer, the following describes the technical solutions in the embodiments of the present invention clearly and completely with reference to the drawings in the embodiments of the present invention:
as shown in fig. 1-5, the method for monitoring the constrained torsional deformation of the closed-section thin-wall beam includes the following steps: the method comprises the steps of measuring the surface strain of the closed-section thin-wall beam in real time to calculate the corner and the warping displacement, selecting a strain measurement point on the surface of the closed-section thin-wall beam along the axial direction, pasting a strain sensor on the test point, measuring the axial strain in real time, calculating the sector area of the section of the closed-section thin-wall beam, and deducing the torsion angle and the warping displacement of each cross section through the strain measurement value and the sector area, thereby realizing the real-time monitoring of the torsion deformation.
Further, the cross section torsion angle and the buckling displacement of the closed-section thin-wall beam are calculated in the following mode:
s1: calculating the distribution of the sector area omega(s) of the section of the thin-wall beam:
wherein s is the curve coordinate of the measuring point on the section outline, h(s) is the distance from the rotation center to the tangent of the s point,for the shearing redundancy, the calculation method comprises the following steps:
wherein J is the free torsional moment of inertia, t is the wall thickness, AmIs the closed cross-sectional area;
s2: dividing the beam into a plurality of measuring sections along the axial direction, wherein the length of each measuring section is equal;
s3: at the end point of each measuring section, the measuring point of the strain sensor is arranged on the surface of the beam, and the position of the measuring point is x0，x1，x2，…xnWhere n +1 is the number of measurement points, x0At one end of the beam, xnAt the other end of the beam, with the other measurement point at x0And xnAre arranged in sequence; x is the number of1To xnArranged on a straight line parallel to the beam axis; on the beam section, the coordinate of the outline corresponding to the measuring point is sm；
In the measuring section [ x ]i-1,xi]Above, the strain expression is:
wherein epsiloni-1And εiIs xi-1And xiThe strain measurement at (a), the x-direction being the beam axis direction;
s4: the relationship between the surface strain and the torsion angle is obtained as follows:
wherein,is the torsion angle, ω(s)m) Is the cross-sectional sector area at the measurement point;
s5: obtaining a relation between the section warping displacement and the strain as follows:
u(x)＝∫ε(x)dx(5)
s6: and (3) deducing a warping displacement calculation formula of any section and any position on the section by combining the formulas (1), (2), (3) and (5):
wherein u isiIs xiIs the warp displacement,. DELTA.l is the distance between the measuring points,. epsilonj-1And εjIs xj-1And xjMeasured value of strain of (u)0Is x0Warp displacement of (c) for a clamped beam at one end, u0＝0；
S7: based on equation (4), in the measurement section [ x ]i-1,xi]Above, there are
S8: combining the formulas (1), (2), (3) and (7) to obtain xiThe twist angle of (d) is:
where Δ l is the distance between the measuring points, ω(s) is the sector area of the measuring location, ε0，εiAnd εjIs x0，xiAnd xjThe measured value of the strain at (a),and u0Is x0Torsion angle and warp displacement of the beam, for a clamped beam at one end
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (1)
1. A real-time monitoring method for constrained torsional deformation of a closed-section thin-wall beam is characterized by comprising the following steps: selecting a strain measurement point on the surface of the closed section thin-wall beam along the axial direction, sticking a strain sensor on the strain measurement point, measuring the axial strain in real time, calculating the sectional fan-shaped area of the closed section thin-wall beam, and deducing the torsion angle and the warping displacement of each cross section through the strain measurement value and the fan-shaped area so as to monitor the torsion deformation of the closed section thin-wall beam in real time;
the cross section torsion angle and the buckling displacement of the closed section thin-wall beam are calculated in the following mode:
s1: calculating the distribution of the sector area omega(s) of the section of the thin-wall beam:
where s is the point of measurement atThe curve coordinate on the contour line of the surface shape, h(s) is the distance from the rotation center to the tangent line of the point s,for the shearing redundancy, the calculation method comprises the following steps:
wherein J is the free torsional moment of inertia, t is the wall thickness, AmIs the closed cross-sectional area;
s2: dividing the beam into a plurality of measuring sections along the axial direction, wherein the length of each measuring section is equal;
s3: at the end point of each measuring section, the measuring point of the strain sensor is arranged on the surface of the beam, and the position of the measuring point is x0，x1，x2，…xnWhere n +1 is the number of measurement points, x0At one end of the beam, xnAt the other end of the beam, with the other measurement point at x0And xnAre arranged in sequence; x is the number of1To xnArranged on a straight line parallel to the beam axis; on the beam section, the coordinate of the outline corresponding to the measuring point is sm；
In the measuring section [ x ]i-1,xi]Above, the strain expression is:
wherein epsiloni-1And εiIs xi-1And xiThe strain measurement value is measured, the x direction is the beam axis direction, i represents the serial number of the measurement point, and delta l represents the distance between the measurement points;
s4: the relationship between the surface strain and the torsion angle is obtained as follows:
wherein,is the torsion angle, ω(s)m) Is the cross-sectional sector area at the measurement point;
s5: obtaining a relation between the section warping displacement and the strain as follows:
u(x)＝∫ε(x)dx (5)
s6: and (3) deducing a warping displacement calculation formula of any section and any position on the section by combining the formulas (1), (2), (3) and (5):
wherein u isiIs xiIs the warp displacement,. DELTA.l is the distance between the measuring points,. epsilonj-1And εjIs xj-1And xjMeasured value of strain of (u)0Is x0Warp displacement of (c) for a clamped beam at one end, u0＝0；
S7: based on equation (4), in the measurement section [ x ]i-1,xi]Above, there are
S8: combining the formulas (1), (2), (3) and (7) to obtain xiThe twist angle of (d) is:
where Δ l is the distance between the measuring points, ω(s) is the sector area of the measuring location, ε0，εiAnd εjIs x0，xiAnd xjThe measured value of the strain at (a),and u0Is x0Torsion angle and warp displacement of the beam, for a clamped beam at one end
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810088878.3A CN108413860B (en) | 2018-01-30 | 2018-01-30 | A kind of method of real-time of silent section thin walled beam constrained twisting deformability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810088878.3A CN108413860B (en) | 2018-01-30 | 2018-01-30 | A kind of method of real-time of silent section thin walled beam constrained twisting deformability |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108413860A CN108413860A (en) | 2018-08-17 |
| CN108413860B true CN108413860B (en) | 2019-10-29 |
Family
ID=63127300
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810088878.3A Active CN108413860B (en) | 2018-01-30 | 2018-01-30 | A kind of method of real-time of silent section thin walled beam constrained twisting deformability |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108413860B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110887448B (en) * | 2019-11-28 | 2021-08-20 | 上海航天控制技术研究所 | Beam structure form reconstruction method based on optical fiber strain measurement |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3612587B2 (en) * | 2000-04-18 | 2005-01-19 | 株式会社東京計測 | Link type displacement meter |
| CN102322842A (en) * | 2011-05-25 | 2012-01-18 | 吉林大学 | Simplified analysis method for bending property of box-section thin-wall beam |
| EP2214960B1 (en) * | 2007-12-05 | 2012-02-01 | ONERA (Office National d'Etudes et de Recherches Aérospatiales) | Elongated, torsion-deformable aerodynamic element |
| CN106524894A (en) * | 2016-09-29 | 2017-03-22 | 宇龙计算机通信科技(深圳)有限公司 | Flexible screen bending degree detection method and terminal |
| CN106524989A (en) * | 2016-12-14 | 2017-03-22 | 上海建工建集团有限公司 | Large-scale foundation pit support body deformation automation analysis system and data analysis method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160064639A (en) * | 2014-11-28 | 2016-06-08 | 현대위아 주식회사 | Apparatus for measuring an object to be measured |
-
2018
- 2018-01-30 CN CN201810088878.3A patent/CN108413860B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3612587B2 (en) * | 2000-04-18 | 2005-01-19 | 株式会社東京計測 | Link type displacement meter |
| EP2214960B1 (en) * | 2007-12-05 | 2012-02-01 | ONERA (Office National d'Etudes et de Recherches Aérospatiales) | Elongated, torsion-deformable aerodynamic element |
| CN102322842A (en) * | 2011-05-25 | 2012-01-18 | 吉林大学 | Simplified analysis method for bending property of box-section thin-wall beam |
| CN106524894A (en) * | 2016-09-29 | 2017-03-22 | 宇龙计算机通信科技(深圳)有限公司 | Flexible screen bending degree detection method and terminal |
| CN106524989A (en) * | 2016-12-14 | 2017-03-22 | 上海建工建集团有限公司 | Large-scale foundation pit support body deformation automation analysis system and data analysis method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 新型承插式F型钢架结构非线性有限元分析及试验研究;夏珊;《中国优秀硕士学位论文全文数据库 基础科技辑》;20081115;正文第13-14页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108413860A (en) | 2018-08-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108519175B (en) | Variable-range soil pressure measuring method based on Bragg fiber grating | |
| CN101923024B (en) | Method for determining elastic modulus and flexural rigidity of reinforced concrete beam with crack | |
| US7715994B1 (en) | Process for using surface strain measurements to obtain operational loads for complex structures | |
| CN105136359B (en) | Method based on the beam surface strain values evaluation work load that fibre optical sensor measures | |
| CN105043285B (en) | Optical fiber sensor-based method for measuring deformation of beam with variable cross section | |
| CN110795884B (en) | Novel hybrid test method based on multi-scale model updating | |
| CN110887448B (en) | Beam structure form reconstruction method based on optical fiber strain measurement | |
| CN104111032A (en) | Fiber bragg grating sensor network based large-scale structure body deformation measurement method | |
| CN105403344B (en) | The acquisition methods of the real-time stress of pipeline | |
| JP5602655B2 (en) | Crack size estimation method | |
| CN108548729B (en) | Method and device for measuring maximum bending stress of material | |
| CN112461190B (en) | Bridge deformation reconstruction method | |
| CN114754691A (en) | Distributed optical fiber monitoring and inversion method for helicopter blade bending form | |
| CN108413860B (en) | A kind of method of real-time of silent section thin walled beam constrained twisting deformability | |
| CN108413861B (en) | A kind of method of real-time of opening section thin walled beam constrained twisting deformability | |
| Guru Prasad et al. | Fiber Bragg grating sensor package for submicron level displacement measurements | |
| CN104567655B (en) | Dynamic angular displacement measuring device and method | |
| Heaney et al. | Distributed sensing of a cantilever beam and plate using a fiber optic sensing system | |
| CN114417537B (en) | Open type walking framework structure deformation field real-time measurement method, device and system | |
| Liu et al. | Reconstruction algorithm for obtaining the bending deformation of the base of heavy-duty machine tool using inverse finite element method | |
| JP2008051637A (en) | Method for measuring bending stress of fixed structure, recording medium, and computer | |
| JP7057187B2 (en) | Beam damage evaluation method | |
| KR20180019396A (en) | Similitude Law and Pseudodynamic Test Method of Reinforced Concrete Structure by Modifying Analytic Parameter Considering Measured Strain Data | |
| CN108195532B (en) | Method for measuring equivalent rigidity of beam structure crack | |
| CN112595254A (en) | Method for measuring structure bidirectional strain gradient field, sensor and application |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |