CN108021775B - Method for calculating bending strength of upright post of dust remover box under action of transverse load - Google Patents
Method for calculating bending strength of upright post of dust remover box under action of transverse load Download PDFInfo
- Publication number
- CN108021775B CN108021775B CN201711459748.8A CN201711459748A CN108021775B CN 108021775 B CN108021775 B CN 108021775B CN 201711459748 A CN201711459748 A CN 201711459748A CN 108021775 B CN108021775 B CN 108021775B
- Authority
- CN
- China
- Prior art keywords
- section
- upright
- column
- upright column
- bending moment
- 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.)
- Expired - Fee Related
Links
- 238000005452 bending Methods 0.000 title claims abstract description 106
- 238000000034 method Methods 0.000 title claims abstract description 43
- 239000000428 dust Substances 0.000 title claims abstract description 41
- 230000009471 action Effects 0.000 title claims abstract description 29
- 238000004364 calculation method Methods 0.000 claims abstract description 72
- 238000012937 correction Methods 0.000 claims abstract description 20
- 230000008569 process Effects 0.000 claims description 15
- 238000006243 chemical reaction Methods 0.000 claims description 10
- 238000009826 distribution Methods 0.000 claims description 10
- 230000014509 gene expression Effects 0.000 claims description 8
- 230000000694 effects Effects 0.000 claims description 7
- 238000004590 computer program Methods 0.000 claims description 4
- 238000004458 analytical method Methods 0.000 abstract description 3
- 238000010276 construction Methods 0.000 description 9
- 229910000831 Steel Inorganic materials 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 7
- 239000010959 steel Substances 0.000 description 7
- 230000008859 change Effects 0.000 description 6
- 238000013461 design Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 238000013519 translation Methods 0.000 description 4
- 238000009795 derivation Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000003351 stiffener Substances 0.000 description 2
- NAWXUBYGYWOOIX-SFHVURJKSA-N (2s)-2-[[4-[2-(2,4-diaminoquinazolin-6-yl)ethyl]benzoyl]amino]-4-methylidenepentanedioic acid Chemical compound C1=CC2=NC(N)=NC(N)=C2C=C1CCC1=CC=C(C(=O)N[C@@H](CC(=C)C(O)=O)C(O)=O)C=C1 NAWXUBYGYWOOIX-SFHVURJKSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 238000010205 computational analysis Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000010297 mechanical methods and process Methods 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012716 precipitator Substances 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- XGVXKJKTISMIOW-ZDUSSCGKSA-N simurosertib Chemical compound N1N=CC(C=2SC=3C(=O)NC(=NC=3C=2)[C@H]2N3CCC(CC3)C2)=C1C XGVXKJKTISMIOW-ZDUSSCGKSA-N 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/17—Mechanical parametric or variational design
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Theoretical Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Evolutionary Computation (AREA)
- Computer Hardware Design (AREA)
- General Engineering & Computer Science (AREA)
- Pure & Applied Mathematics (AREA)
- Mathematical Optimization (AREA)
- Mathematical Analysis (AREA)
- Computational Mathematics (AREA)
- Rod-Shaped Construction Members (AREA)
- Peptides Or Proteins (AREA)
Abstract
The invention discloses a method for calculating the bending strength of a vertical column of a dust remover box under the action of a transverse load, and engineering designers can conveniently and accurately calculate the maximum section bending moment of the internal force of a middle vertical column when a box wallboard is subjected to the action of the transverse load according to a formula and a related calculation coefficient table provided by the invention; considering the cooperative work of the wall plate and the upright column, the wall plates in the effective widths of the two sides of the upright column are used as the extending parts of the flanges of the upright column to form a combined section, and share bending moment with the upright column, so that the modulus of the section of the upright column is multiplied by a correction coefficient gamma, and finite element calculation analysis of a plurality of embodiments shows that the gamma can be deviated from a safe value of 1.06, thereby carrying out the bending strength checking calculation of the section of the upright column.
Description
Technical Field
The invention relates to a method for calculating the bending strength of a dust remover box body stand column under the action of transverse load, and belongs to the technical field of structures.
Background
The dust remover is a main environmental protection device which is widely applied to the industries of thermal power, metallurgy, chemical industry, building materials and the like to eliminate smoke dust, and the box body is the most important process part. When the box body enclosure structure adopts a straight steel plate wallboard-H-shaped (or I-shaped) section upright column structure system with stiffening ribs, one side flange of the H-shaped section upright column is continuously welded and connected with the steel plate wallboard to form a stressed whole. The box body wallboard mainly directly bears transverse loads such as air negative pressure (action from outside to inside) and wind load formed by temperature difference between inside and outside, and the vertical column is a supporting boundary at two sides of the wallboard, so that the load can be transmitted to the vertical column, and the vertical column bears the transverse load. When the structure of the box body of the dust remover is designed, an accurate and reliable method for calculating the bending strength of the box body stand column when transverse load is directly acted on the wall plate of the box body needs to be provided.At present, the commonly used column bending strength simplified calculation method in engineering design is as follows: the wallboard is regarded as a uniform and same-polarity one-way stress board in a simple and conservative way, the transverse load borne by the board is uniformly distributed on the upright columns at two adjacent sides, the cooperative work after the wallboard and the upright columns are connected is not considered, the upright columns are regarded as an independent working uniform-section multi-span continuous beam which is supported in a span way and is loaded by a uniform distribution line, and the maximum bending moment M of the beam issCan be obtained according to a linear elastic structure mechanical method. The simplified calculation method has the advantages that firstly, the force transmission mechanism is not accurate enough, the wall plate of the dust remover box body is not a one-way force transmission plate, and the force transmission effect of stiffening ribs on the wall plate needs to be considered; secondly, the stress carrier is not accurate enough, the cooperative work of the wallboard and the upright column is not considered, and the transverse load borne by the wallboard is completely transmitted to the upright column for bearing, so the engineering simplified calculation method can cause overlarge calculation internal force.
Disclosure of Invention
In view of the fact that the accuracy of the conventional calculation method is not enough, the invention provides a more accurate, reliable and comprehensive calculation method for the bending strength of the upright post of the dust remover box under the action of the transverse load.
The invention aims to provide a bending strength calculation method with more reasonable stress model and higher result accuracy aiming at the defects of the engineering simplified calculation method of the bending strength of the existing dust remover box body stand column under the action of transverse load, and the design of the stand column section can be optimized to a certain extent. In the derivation and formation process, the invention covers the geometric dimensions of small, medium and large dust collectors according to the structure of the dust collector of the actual project.
A method for calculating the bending strength of a dust remover box body upright post under the action of transverse load has the following application range: the wall plate of the dust remover box body is a steel plate with stiffening ribs, the wall plate is acted with a load which is transversely and uniformly distributed, the wall plate is continuously welded and connected with the flange at one side of the upright column, the upright column is rolled H-shaped steel, rolled I-shaped steel or welded with an H-shaped section, the upright column is a middle supporting upright column of the dust remover box body but not an edge upright column, and the interior of the dust remover box body supports the upright columns in the direction of the vertical wall plate which is arranged at equal intervals; the method comprises the first step of solving boundary transverse reaction force by taking a wallboard cell formed by enclosing an upper stiffening rib, a lower stiffening rib, a left upright post and a right upright post as an independent working elastic plate with four sides simply supported and transversely and uniformly loaded without considering the cooperative work of the wallboard and the upright posts; secondly, reversely applying the transverse reaction force of the boundary of each cell wallboard to the upright column, and solving the bending moment of the upright column serving as an independently working uniform-section multi-span continuous beam; and thirdly, determining an effective part of the cooperative stress of the wall plate and the upright column, regarding the effective part as the extension of the flange of the upright column, forming a combined section with the upright column, and calculating the maximum positive stress on the upright column to complete the calculation of the bending strength of the upright column.
The maximum bending moment M of the middle upright post occurs at the cross section of the first span supporting part at the top of the upright post when the wall board of the dust remover box body is transversely loadedtCan be calculated as follows:
Mt＝α[(n×a)2pb] (1)
in the formula, n is the number of the wall plate cells between every two spans of the upright posts;
a is the interval of the stiffening ribs on the wallboard, and the unit is: mm;
b is the width of the wallboard between adjacent upright posts, and the unit is: mm;
p is the horizontal equipartition load value such as negative pressure and wind load, and the unit is: n/mm2；
Alpha is the calculation coefficient of the maximum bending moment of the section of the upright column, and is shown in tables 1 to 5.
TABLE 1 calculation coefficient of maximum bending moment of two-span vertical column section
TABLE 2 three-span column section maximum bending moment calculation coefficient
TABLE 3 maximum bending moment calculation coefficient of four-span column section
TABLE 4 maximum bending moment calculation coefficient of cross section of five-span vertical column
TABLE 5 maximum bending moment calculation coefficient of six-span vertical column section
The invention adopts a moment distribution method to solve the maximum bending moment M of the control section of the upright columntIn the process, the column sections which are fixed at two ends and span n wallboard cells are subjected to non-uniformly distributed loads q directly transmitted from one side wallboard to the stand columncAnd the concentrated force 2F transmitted to the upright column at the connecting point of the stiffening rib and the upright column is used for deducing and obtaining the fixed end bending moment calculation formula of the span upright column under the action of transverse load as follows:
F＝Fs/2-Fc (6)
in order to conveniently compile a computer program to carry out numerical calculation on the fixed end bending moment, the fixed end bending moment expression of the upright post under the condition of fixed two ends is rewritten as follows:
in the formula, l is a span length of the upright column, and the unit is: mm;
k is the number of the wallboard cells from the calculated infinitesimal section to the calculation starting end (end A);
i is the intermediate process coefficient.
The invention adopts a moment distribution method to solve the maximum bending moment M of the control section of the upright columntIn the process, one end of the vertical column is fixed, the other end of the vertical column is hinged, n wall plate cells are arranged between the vertical column and the vertical column, and the load q is directly transmitted from one side wall plate to the vertical column and is unevenly distributedcAnd the concentrated force 2F transmitted to the upright column at the connecting point of the stiffening rib and the upright column is used for deducing and obtaining the fixed end bending moment calculation formula of the span upright column under the action of transverse load as follows:
in order to conveniently compile a computer program to carry out numerical calculation on the fixed end bending moment, the fixed end bending moment expression of the upright post with one fixed end and one hinged end is rewritten as follows:
in the formula, l is a span length of the upright column, and the unit is: mm;
k is the number of the wallboard cells from the calculated infinitesimal section to the calculation starting end (end A);
i is the intermediate process coefficient.
In the invention, the synergistic bending moment resisting effect of the wall plate and the upright is considered, the wall plate in the effective width is used as an extension part of an upright flange and forms a combined section with the upright section, the modulus of the upright section is multiplied by a correction coefficient gamma to obtain the modulus of the section of the combined section, and the maximum bending positive stress of the upright can be obtained by using the following formula;
σmax＝Mt/(γ×WH) (10)
in the formula, gamma is a column section modulus correction coefficient, and the safety value is 1.06;
WHis the column section modulus, with the unit: mm is3。
The method for calculating the bending strength of the upright post of the dust remover box body under the action of the transverse load has the advantages that:
1. the accuracy is high, and the considered factors are comprehensive: the force transmission mechanism is more accurate by considering the force transmission effect of the stiffening ribs on the wallboard; consider the cooperative work of the wall panel and the upright; compared with the current engineering simplified calculation method, the method is more accurate and reliable.
2. The use is convenient: according to the calculation formula and the calculation table provided by the invention, the maximum section normal stress sigma of the internal force of the middle upright post when the wall plate of the box body of the dust remover is subjected to the action of transverse load can be directly obtainedmaxThe cross section bending strength can be calculated conveniently and accurately.
Drawings
FIG. 1 is a structural model and a displacement coordinate system according to the present invention.
FIG. 2 is a diagram of the reaction force distribution and coordinate system of the boundary of the four-side simply-supported plate of the present invention.
Fig. 3 is a schematic diagram of the stress of the upright post under the action of transverse load in the invention.
FIG. 4 is a comparison of the load results when the upper limit m' of the order is different.
FIG. 5 is a schematic diagram of the force applied to a fixed post across two ends of the present invention.
FIG. 6 is a schematic diagram of the forces applied to a fixed end-span and hinged end-span upright post of the present invention.
Detailed Description
The technical solution of the present invention will be described in detail below with reference to the accompanying drawings by way of specific embodiments, so as to further illustrate the technical solution features of the present invention and the forming process thereof. It is to be understood that the embodiments described herein are illustrative only and are not limiting upon the present invention.
The first step is to calculate the maximum bending moment of the upright post caused by the distribution and transmission of the transverse load borne by the wallboard to the upright post.
The wall plate-column structure system of the dust collector box body is shown as attached figure 1. The wall board of the dust collector box body directly bears the action of transversely uniformly distributed loads p, and the transverse loads are distributed and transmitted to the upright posts on the two sides of the wall board to cause the upright posts to bear bending moment. The method comprises the first step of calculating the transmission of the transverse load to the upright posts, and solving the boundary transverse counter force by taking the wall plate cells formed by the upper and lower adjacent stiffening ribs and the upright posts on the left and right sides as an independent working elastic plate with four sides simply supported and transversely uniformly loaded without considering the cooperative work of the wall plate and the upright posts. The width of the four-side simply-supported plate is a span wallboard width b, the height of the four-side simply-supported plate is a wallboard stiffening rib interval a, the thickness of the wallboard is t, and the stress of one wallboard cell is shown in the attached figure 2. Negative pressure, wind load and other transverse uniformly distributed loads p are directly applied to each wallboard cell of the box body, and then the vertical columns on the left side and the right side and the stiffening ribs on the upper end and the lower end are transmitted. The transverse distribution boundary counter force provided by the upright columns at the left side and the right side of the wall panel section is VyActing in reverse on the column as a transverse line load q directly borne by the columnc. The transverse boundary counter force provided by the stiffening ribs at the upper end and the lower end of the wall panel cells is VxThe resultant force is FsThe stiffening ribs are connected with the upright columns at two sides through connecting plates, and the stiffening rib at one side provides resultant force F of boundary counter forcesAnd/2, reversely acting on the connection points of the stiffening ribs and the upright posts to serve as concentrated transverse loads transmitted by the boundaries of the upper end and the lower end of each wallboard cell. In addition, concentrated reaction forces R are also arranged on four corner points of each wallboard cell and are also reversely applied to connecting points of the stiffening ribs and the upright posts to serve as concentrated transverse loads F transmitted to the upright posts by the corner points of the wallboard cellsc. The stand is equipped with equidistant horizontal support along the direction of height, provides the restraint of perpendicular wallboard direction for it, and the stand span is support interval l promptly, and each is striden and has corresponding n wallboard district check. Taking the three-span middle upright post as an example, the stress sketch when the transverse load transmitted by the single-side wall plate is received is shown as attached figure 3.
The boundary transverse counter-force of a wallboard cell adopts a simple supporting moment of opposite sidesA single triangular step array dimensional solution of the shaped plate. The wallboard width b is greater than the stiffener spacing a according to conventional duster design geometry. Transverse boundary counter force V provided by upper and lower end stiffening ribs of wallboard cellxCalculated as follows:
in the formula, m is the order of the series, and is an odd number of 1,3 and 5 …; coefficient alpham、Am' and Bm' are calculated as follows:
the transverse concentration force transmitted to the upright column by the stiffening rib corresponding to one end of one wallboard cell is as follows:
a wall plate area lattice (x is more than or equal to 0 and less than or equal to a) transmits a transversely distributed load q on the upright post at one sidecEqual in value to the transverse counter force V of the left and right side boundaries of the wall panelyCalculated as follows:
concentrated transverse load F transmitted from each wallboard area grid corner point to upright postcThe central reaction force R which is equal to the four corner points of the wall panel in value is calculated according to the following formula:
the answers are infinite series, and in the actual engineering calculation, the value of m always has an upper limit. If the upper limit value of m is too large, the calculation efficiency is low; if the upper limit value of m is too small, the result is not accurate enough. The invention adopts MATLAB language to write a calculation program, obtains the influence of the upper limit value of m by comparing and analyzing the numerical calculation of various calculation results when different upper limit values are taken for m, and then determines the reasonable upper limit value of m.
Taking the lattice a of the wall plate of the calculation example as 1000mm, uniformly distributing the load p as 9000Pa, and calculating the load results when the upper limit value m' of m is changed as shown in (a), (b) and (c) in the attached figure 4 respectively.
The curves of different values of the upper limit m in FIG. 4(a) are almost coincident, which shows that the resultant force F of the summation order of changing the number of stages in the solution to the counterforce of the upper and lower side boundaries of the wallboard gridsThe size has little effect. FIG. 4(b) shows that the maximum lateral reaction force V of the wall panel cell column side boundary is obtained when the upper limit value of m is small in different wall panel cell width-height ratiosy,maxThe difference is large; when the m upper limit value is 21 or more, the numerical calculation results tend to be equal. Fig. 4(c) shows that when the upper value of m is 21 or more, the numerical calculation results of the concentrated reaction force R at the corner points of the wallboard region tend to be equal. Taking the case that the height-width ratio b/a of the wall panel lattice of the conventional dust collector box is 4 as an example, when the upper limit value m 'is 21 and the upper limit value m' is 201, the resultant force F of the reaction forces of the upper and lower side boundaries of the wall panel lattice is increasedsThe yield is changed from 16.413KN to 16.412KN, and the reduction is 0.01 percent; maximum transverse counter force V of side boundary of wall panel section lattice columny,maxThe concentration is changed from 4.515KN/m to 4.51KN/m, and the reduction is 0.11%; the concentrated reaction force R at the corner points of the wallboard area is changed from 0.8543KN to 0.8547KN, and is improved by 0.05%. The numerical calculation efficiency and precision are comprehensively considered, and the m upper limit value is 21 for each solution in subsequent calculation.
When the internal force of each cross section of the upright column is solved, the cross section can be regarded as a uniform cross section multi-span continuous beam. Considering that the geometrical size and the form and the size of the load borne by each span upright post are the same, and the supporting position does not laterally move, the moment distribution method is adopted to solve the maximum bending moment of the control section of the upright post. The fixed end bending moment of the inner upright post of a span under the action of load needs to be solved, and the fixed end bending moment comprises two constraint conditions that the far end is fixed and the far end is hinged.
Get a dust remover box middle standing pillar that span is l, assume that its both ends are fixed, stride and correspond n wallboard district check, receive a distribution load q that a lateral wall board directly transmitted to the standcAnd a concentrated force 2F transmitted to the upright column by the side wall plate cells at the position of the stiffening rib boundary and the upright column connecting point, and the stress diagram is shown as an attached figure 5. According to the balance relation and the displacement coordination condition, the bending moment of the fixed end of the straddle column under the action of transverse load can be deduced
As shown in the following formula:
F＝Fs/2-Fc (6)
wherein k is the calculated number of the wall panel cells from the infinitesimal section to the A end.
For an upright post with one span and one fixed end and the other hinged end, a calculation sketch is shown in figure 6, and the fixed end bending moment can be obtained through derivation
When MATLAB language is adopted to carry out numerical calculation on the fixed end bending moment, because the expressions in the formula (8) and the formula (10) have absolute value terms, direct integral solving can not be carried out, so that the expressions are transformed, and the expressions of the fixed end bending moment of the upright column under the condition that the two ends are fixed are rewritten as follows:
in the formula, i is an intermediate process coefficient.
The fixed end bending moment expression of the condition that one end is fixed and the other end is hinged is rewritten as follows:
the rigidity of each span line of the upright post is equal, the bending moment distribution coefficients of two sides of the cross section of the supporting position between the spans can be determined according to the total span number and the far-end constraint condition, and then the bending moment of the cross section of the supporting position between the spans of the upright post can be obtained. Calculation shows that the maximum bending moment value is arranged at the first span bearing position on the upright post, so that for the upright post with the equal section, the bending strength of the section at the position is only required to be checked during strength design, and subsequent analysis mainly aims at the bending moment of the first span bearing position of the upright post. The bending moment obtained by the calculation only considers the transverse load transmitted by the single-side wall plate of the upright column, in fact, the two sides of the middle upright column of the box body are provided with the wall plates, the loads transmitted by the wall plates at the two sides are considered, and the result is multiplied by 2, so that the maximum bending moment value of the cross section of the middle upright column can be solved.
The following embodiments summarize and formulate the maximum bending moment of the control section of the upright post in consideration of the span number of upright posts of the dust remover box body, the number of corresponding wall plate cells in the range of each span upright post and the width-height ratio of the wall plate cells.
Example 1:
the upright post of the dust remover box body is a two-span upright post; the number n of the wall plate cells between every two spans of the upright posts is 1; the distance a between the stiffening ribs on the wallboard is 600mm, the width b of a span wallboard is 600mm, namely b/a is 1; the column span l is n × a is 600 mm; the value p of the transverse uniformly distributed loads such as negative pressure, wind load and the like is 0.008N/mm2. Maximum bending moment M of section of middle upright post calculated by MATLAB language programmingtM was calculated as shown in Table 1 by the above methodtThe value is independent of the section size of the upright post.
Example 2 to example 54:
example 2EExample 54 relative to example 1, only the number n of wall panels between each span of the column and the width b of a span of wall panels were changed, and the size of b/a, specific construction parameters and the maximum bending moment M of the section of the center column calculated by the MATLAB language programming were changedtAs shown in table 1.
Example 55:
the upright post of the dust remover box body is a two-span upright post; the number n of the wall plate cells between every two spans of the upright posts is 1; the distance a between the stiffening ribs on the wallboard is 1000mm, the width b of a span wallboard is 1000mm, namely b/a is 1; the column span l is n × a is 1000 mm; the value p of the transverse uniformly distributed loads such as negative pressure, wind load and the like is 0.009N/mm2. Maximum bending moment M of section of middle upright post calculated by MATLAB language programmingtAs shown in table 1.
Example 56 to example 108:
examples 56-108 relative to example 55, only the number of wall panels, n, per span of the column and the width, b, of a span of wall panels were varied, and the size of b/a, specific construction parameters and the maximum bending moment, M, of the cross-section of the center column calculated using MATLAB language programming were variedtAs shown in table 1.
TABLE 1
The maximum bending moment M of the section of the middle upright post in the embodiment of the two-span structure is analyzed and comparedtIt was found that the maximum bending moment of the center column section was mainly related to the span, the width of the wall panel, the spacing between the stiffening ribs and the uniform face load applied to the wall panel, and statistical summary of the results showed that M is the maximum bending moment of the center column sectiont/[(n×a)2pb]The value of which is a number related only to n and b/a, and thereforeThe calculation formula (1) can be extracted.
Example 109 to example 216:
in the embodiments 109 to 216, compared with the embodiments 1 to 108, only the upright post is changed into the three-span upright post, and the rest parameters are not changed. Concrete construction parameters and calculation of maximum bending moment M of section of middle upright column by using MATLAB language programmingtAs shown in table 2.
TABLE 2
Example 217 to example 324:
in the embodiments 217 to 324, compared with the embodiments 1 to 108, only the upright post is changed into the four-span upright post, and the rest parameters are not changed. Concrete construction parameters and calculation of maximum bending moment M of section of middle upright column by using MATLAB language programmingtAs shown in table 3.
TABLE 3
Examples 325 to 432:
example 325 to practiceIn example 432, only the vertical column is changed into a five-span vertical column relative to examples 1 to 108, and the rest parameters are not changed. Concrete construction parameters and calculation of maximum bending moment M of section of middle upright column by using MATLAB language programmingtAs shown in table 4.
TABLE 4
Example 433 to example 540:
in examples 433 to 540, only the vertical column was changed to a six-span vertical column, and the remaining parameters were not changed, compared to examples 1 to 108. Concrete construction parameters and calculation of maximum bending moment M of section of middle upright column by using MATLAB language programmingtAs shown in table 5.
TABLE 5
The maximum bending moment M of the section of the middle upright post in the embodiment is calculated in the research and development process of the inventiontThe statistical conclusion of the results shows that the main influence parameters of the maximum bending moment of the section of the upright column obtained by the calculation method of the invention include the span number and the span l ═ n of the upright columnX a, wallboard width b, wallboard stiffener spacing a, and uniform surface load p applied to the wallboard. Because the load bearing action form of the upright post is certain, in order to facilitate the engineering calculation application, the invention introduces the calculation coefficient alpha of the maximum bending moment of the section of the middle upright post when the wall board of the dust remover box body is subjected to the transverse load, and the theoretical calculation value of the maximum bending moment of the section of the middle upright post can be obtained by using the formula (1). And compiling a coefficient alpha table according to the span number of the upright columns of the dust remover box body, the number of the corresponding wall plate cells in each span upright column range and the width-height ratio of the wall plate cells, as shown in tables 6-10.
TABLE 6 maximum bending moment calculation coefficient of two-span vertical column section
TABLE 7 three-span column section maximum bending moment calculation coefficient
TABLE 8 maximum bending moment calculation coefficient of four-span column section
TABLE 9 maximum bending moment calculation coefficient of cross section of five-span vertical column
TABLE 10 maximum bending moment calculation coefficient of six-span vertical column section
And in the second step, the maximum normal stress of the control section of the upright column is calculated by considering the cooperative work of the wallboard and the upright column.
The invention can correct and calculate the maximum bending moment M of the control section of the upright column according to the section stress of the upright column obtained by finite element calculationtAnd (4) calculating the bending strength. 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: and the lateral load has small effect on the structural system, and the deformation and stress level are low, so that the line elasticity calculation is carried out. The dust remover is made of Q235 steel with yield strength fy235MPa, E2.06 × 105MPa, and poisson's ratio ν 0.3.
3. Applying a constraint condition: the top end of the wall plate of the dust collector box body is connected with the stiffening top plate of the box body, so that the translation constraint vertical to the direction (Z direction) of the wall plate is applied to the top boundary of the wall plate. 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 transverse supports (vertical to the direction of the wall plate) which are arranged at equal intervals, and the translation restraint vertical to the direction of the wall plate is exerted at the joints of the vertical columns and the transverse supports. 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 post at the edge of two sides only applies the restraint along the height direction (X 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 (Y direction) of the wallboard.
4. And (3) applying a load condition: the wall plate of the dust collector box body is subjected to wind load and internal and external pressure difference (negative pressure) in the operation process to generate a transverse uniformly distributed load vertical to the wall plate, and the transverse uniformly distributed load is applied to the wall plate to be 0.009 MPa.
Compared with a finite element method, the column bending strength theoretical calculation method provided by not considering the cooperative stress of the wall plate and the column is conservative and is used for carrying outThe strength design of the upright under the action of transverse load can cause the section to be too large and not economic enough, so the theoretical calculation method of the maximum bending moment of the upright, which is provided by the first part of the invention, needs to be corrected. The specific idea is that the theoretical calculation method provided by the invention is adopted to solve the maximum bending moment M on the upright columntThe width of two sides of the upright post is bweThe wall board (defined as an effective width inner wall board) and the upright post form a combined section, and share the action of bending moment, so that the maximum normal stress generated on the combined section is equal to the maximum normal stress of the upright post section calculated by a finite element method, and the section modulus W of the combined section is equal to that of the upright posts' can be obtained from formula (15).
Ws'＝Mt/σFEM (15)
In the formula, σFEMMaximum normal stress of control section (bending moment maximum section) calculated by finite element method, MFEMThe bending moment value N borne by the H-shaped section upright post calculated by a finite element methodFEMAxial force value, W, borne on the H-section upright column calculated by finite element methodHAnd AHRespectively the section modulus and the sectional area of the H-shaped section upright post.
Introducing a column section modulus correction coefficient gamma:
γ＝Ws'/WH (17)
by utilizing the modulus correction coefficient gamma of the section of the upright column, engineering designers can conveniently and accurately calculate the maximum section normal stress sigma of the internal force of the upright column according to the following formulamaxThereby designing a safe and economic upright post section.
σmax＝Mt/(γ×WH) (10)
The following examples show the effect of various structural parameters on the correction coefficient gamma of the section modulus of the pillar.
Example 541:
the thickness t of the wall plate of the dust remover box body is 6mm, the width b of the wall plate is 3850mm, the distance a between the angle steel stiffening ribs is 1126mm,the number n of stiffening rib cells in each span of the upright is 4, the transverse supporting interval of the upright is 4504mm, the upright is a three-span upright, the total height H of the upright is 14972mm, the section of the upright is H250mm mm multiplied by 175mm multiplied by 7mm multiplied by 11mm, and the section area A of the upright is 5523mm2Vertical column section moment of inertia IyIs 6.8 multiplied by 107mm4Modulus of column section WHIs 5.2X 105mm3. The contribution of the wall plate to the load will change due to the change in wall thickness of the wall plate, and the column section modulus correction factor γ is shown in table 11.
Embodiment 542, embodiment 543, embodiment 544, embodiment 545 and embodiment 546:
example 542, example 543, example 544, example 545 and example 546 only changed the precipitator box wall panel thickness t relative to example 541, and the specific construction parameters and the column section modulus correction factor γ are shown in table 11.
TABLE 11
Example 547, example 548, example 549, example 550 and example 551:
example 547, example 548, example 549, example 550 and example 551 changed only the width b of the box wall panel of the dust collector relative to example 541, and the specific construction parameters and the correction coefficient gamma of the section modulus of the upright column are shown in table 12.
TABLE 12
Example 552, example 553, example 554 and example 555:
example 552, example 553, example 554 and example 555 with respect to example 541 onlyChange dust remover box stand cross-section moment of inertia IyThe specific structural parameters and the column section modulus correction coefficient γ are shown in table 13.
Example 556, example 557, example 558 and example 559:
the example 556, the example 557, the example 558 and the example 559 only change the transverse supporting distance l of the upright post of the dust collector box body relative to the example 541, and the specific construction parameters and the cross-section modulus correction coefficient gamma of the upright post are shown in the table 14.
TABLE 14
When the comparative example groups 541, 542, 543, 544, 545 and 546 are examined, the wall thickness of the wall board is increased from 4mm to 9mm, the wall thickness is increased by 125%, and the change range of the section modulus correction coefficient gamma value of the upright post is only reduced from 1.11 to 1.08 and reduced by 2.7%.
When the comparative example groups 541, 547, 548, 549, 550 and 551 are examined, the width of the wallboard is increased from 2750mm to 5500mm, the width is increased by 100%, and the change range of the section modulus correction coefficient gamma value of the upright post is only increased from 1.07 to 1.09, and is increased by 1.87%.
Looking at the comparative example groups 541, 552, 553, 554, 555, the column section moment of inertia is from 4.2 × 107mm4Increased to 1.1 × 108mm4And the change range of the section modulus correction coefficient gamma value of the upright post is increased from 1.06 to 1.12 by 5.66 percent.
When the comparative example groups 541, 556, 557, 558 and 559 are examined, the transverse supporting distance of the upright posts is increased from 2500mm to 6500mm, the transverse supporting distance is increased by 160%, and the section modulus correction coefficient gamma value of the upright posts is only reduced from 1.21 to 1.06 and is reduced by 12.3%.
The comprehensive consideration of the calculation results shows that the variation of the gamma value of the section modulus correction coefficient of the upright post is not very large no matter how the structural parameters are changed, so that the invention is biased to conservatively and uniformly taking the section modulus correction coefficient gamma of the upright post to be 1.06.
The invention discloses a method for calculating the bending strength of a vertical column of a dust remover box under the action of a transverse load, and engineering designers can conveniently and accurately calculate the maximum section bending moment of the internal force of a middle vertical column when a box wallboard is subjected to the action of the transverse load according to a formula and a related calculation coefficient table provided by the invention; considering the cooperative work of the wall plate and the upright column, the wall plates in the effective widths of the two sides of the upright column are used as the extending parts of the flanges of the upright column to form a combined section, and share bending moment with the upright column, so that the modulus of the section of the upright column is multiplied by a correction coefficient gamma, and finite element calculation analysis of a plurality of embodiments shows that the gamma can be deviated from a safe value of 1.06, thereby carrying out the bending strength checking calculation of the section of the upright column.
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 (5)
1. The method for calculating the bending strength of the upright post of the dust remover box under the action of transverse load is characterized by comprising the following steps of: step one, not considering the cooperative work of the wall board and the upright columns, taking a wall board cell formed by the upper and lower adjacent stiffening ribs and the upright columns on the left and right sides as an independent working elastic board with four sides simply supported by transversely uniformly distributed loads, and solving the transverse counter force of the boundary; secondly, reversely applying the transverse reaction force of the boundary of each cell wallboard to the upright column, and solving the bending moment of the upright column serving as an independently working uniform-section multi-span continuous beam; and thirdly, determining an effective part of the cooperative stress of the wall plate and the upright column, regarding the effective part as the extension of the flange of the upright column, forming a combined section with the upright column, and calculating the maximum positive stress on the upright column to complete the calculation of the bending strength of the upright column.
2. The duster box stand of claim 1 under transverse loadThe bending strength calculation method is characterized in that: when the wall board of the dust collector box body is under the action of transverse load, the maximum bending moment of the middle upright post occurs on the cross section of the first span supporting part at the top of the upright post, and the maximum bending moment M of the middle upright posttCan be calculated as follows:
Mt＝α[(n×a)2pb] (1)
in the formula, n is the number of the wall plate cells between every two spans of the upright posts;
a is the interval of the stiffening ribs on the wallboard, and the unit is: mm;
b is the width of the wallboard between adjacent upright posts, and the unit is: mm;
p is the horizontal equipartition load value such as negative pressure and wind load, and the unit is: n/mm2；
Alpha is the calculation coefficient of the maximum bending moment of the section of the upright post.
3. The method for calculating the bending strength of the upright post of the dust collector box body under the action of the transverse load according to claim 1, characterized by comprising the following steps of: method for solving maximum bending moment M of control section of upright column by adopting moment distribution methodtIn the process, the column sections which are fixed at two ends and span n wallboard cells are subjected to non-uniformly distributed loads q directly transmitted from one side wallboard to the stand columncAnd the concentrated force 2F transmitted to the upright column at the connecting point of the stiffening rib and the upright column is used for deducing and obtaining the fixed end bending moment calculation formula of the section of upright column under the action of transverse load as follows:
F＝Fs/2-Fc (6)
in order to conveniently compile a computer program to carry out numerical calculation on the fixed end bending moment, the fixed end bending moment expression of the upright post under the condition of fixed two ends is rewritten as follows:
in the formula, l is a span length of the upright column, and the unit is: mm;
k is the number of the wall plate cells from the calculated infinitesimal section to the calculation starting end;
i is the intermediate process coefficient.
4. The method for calculating the bending strength of the upright post of the dust collector box body under the action of the transverse load according to claim 1, characterized by comprising the following steps of: method for solving maximum bending moment M of control section of upright column by adopting moment distribution methodtIn the process, one end of the column is fixed, the other end of the column is hinged, the column section of the n wall plate cells corresponding to the span is subjected to non-uniformly distributed load q directly transmitted from one side wall plate to the upright columncAnd the concentrated force 2F transmitted to the upright column at the connecting point of the stiffening rib and the upright column is used for deducing and obtaining the fixed end bending moment calculation formula of the section of upright column under the action of transverse load as follows:
in order to conveniently compile a computer program to carry out numerical calculation on the fixed end bending moment, the fixed end bending moment expression of the upright post with one fixed end and one hinged end is rewritten as follows:
in the formula, l is a span length of the upright column, and the unit is: mm;
k is the number of the wall plate cells from the calculated infinitesimal section to the calculation starting end;
i is the intermediate process coefficient.
5. The method for calculating the bending strength of the upright post of the dust collector box body under the action of the transverse load according to claim 1, characterized by comprising the following steps of: considering the cooperative bending moment resisting effect of the wall plate and the upright column, taking the wall plate in the effective width as an extension part of an upright column flange to form a combined section with the upright column section, multiplying the modulus of the upright column section by a correction coefficient gamma to obtain the modulus of the section of the combined section, and obtaining the maximum bending normal stress of the upright column by using the following formula:
σmax＝Mt/(γ×WH)
(10)
in the formula, MtControlling the maximum bending moment of the cross section for the upright column, wherein the unit is Nmm;
gamma is the modulus correction coefficient of the section of the upright column, and the safety value is 1.06;
WHis the column section modulus, with the unit: mm is3。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711459748.8A CN108021775B (en) | 2017-12-28 | 2017-12-28 | Method for calculating bending strength of upright post of dust remover box under action of transverse load |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711459748.8A CN108021775B (en) | 2017-12-28 | 2017-12-28 | Method for calculating bending strength of upright post of dust remover box under action of transverse load |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108021775A CN108021775A (en) | 2018-05-11 |
| CN108021775B true CN108021775B (en) | 2021-12-24 |
Family
ID=62071989
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711459748.8A Expired - Fee Related CN108021775B (en) | 2017-12-28 | 2017-12-28 | Method for calculating bending strength of upright post of dust remover box under action of transverse load |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108021775B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108984961A (en) * | 2018-08-15 | 2018-12-11 | 江南大学 | Shear Strength Calculation method of the dust collector box body column under lateral load effect |
| CN109711074B (en) * | 2018-12-29 | 2020-10-09 | 江南大学 | Design method of middle upright post in dust remover box body wall plate-rectangular tube upright post structure |
| CN110457836B (en) * | 2019-08-15 | 2021-03-30 | 江南大学 | Design method of middle upright post of dust remover box body wallboard-upright post structure system |
| CN110688787B (en) * | 2019-08-28 | 2023-06-27 | 浙江工业大学 | Bolt group stress determination method for strip-shaped base under action of transverse bending moment locally |
| CN116484475B (en) * | 2023-04-26 | 2024-07-05 | 青岛理工大学 | Computing method for determining up-down connection of foundation pit cat ladder stand column based on rigidity target |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439196A (en) * | 2013-08-28 | 2013-12-11 | 苏州上洋机电科技有限公司 | Detection device for bending strength of junction of power supply wire and plug |
| CN104714478A (en) * | 2014-12-31 | 2015-06-17 | 哈尔滨工业大学 | Heavy double-column vertical lathe cross beam gravity deformation prediction method based on finite difference method |
| JP6267905B2 (en) * | 2013-09-21 | 2018-01-24 | 株式会社安藤・間 | Calculation method for bending strength of flat beams |
| US10123856B2 (en) * | 2014-05-08 | 2018-11-13 | Cagenix, Inc. | Dental framework and prosthesis |
-
2017
- 2017-12-28 CN CN201711459748.8A patent/CN108021775B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439196A (en) * | 2013-08-28 | 2013-12-11 | 苏州上洋机电科技有限公司 | Detection device for bending strength of junction of power supply wire and plug |
| JP6267905B2 (en) * | 2013-09-21 | 2018-01-24 | 株式会社安藤・間 | Calculation method for bending strength of flat beams |
| US10123856B2 (en) * | 2014-05-08 | 2018-11-13 | Cagenix, Inc. | Dental framework and prosthesis |
| CN104714478A (en) * | 2014-12-31 | 2015-06-17 | 哈尔滨工业大学 | Heavy double-column vertical lathe cross beam gravity deformation prediction method based on finite difference method |
Non-Patent Citations (2)
| Title |
|---|
| Analysis on Two Principal Axes Shear Strength of Columns with Different Stirrup Quantity;Zaigen Mu 等;《2010 International Conference on Management and Service Science》;20100916;第1-3页 * |
| 考虑保温箱作用的电除尘器壳体顶梁结构优化设计研究;王登峰 等;《科学技术与工程》;20140618;第14卷(第17期);第265-271页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108021775A (en) | 2018-05-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108021775B (en) | Method for calculating bending strength of upright post of dust remover box under action of transverse load | |
| CN109241629B (en) | Method for determining axial pressure stable bearing capacity of upright column of dust remover box body | |
| CN108073773B (en) | Method for determining axial pressure stable bearing capacity of double-limb combined section column of dust remover box body | |
| CN106799094B (en) | A kind of dust collector box body H-shaped section Column stability enhancing construction and method | |
| Shivacharan et al. | Optimum position of outrigger system for tall vertical irregularity structures | |
| CN106940736B (en) | Longitudinal multi-span instability limit load determination method considering side load effect | |
| CN106621621B (en) | A kind of construction and method enhancing H-shaped section Column stability | |
| CN108984961A (en) | Shear Strength Calculation method of the dust collector box body column under lateral load effect | |
| CN110457836B (en) | Design method of middle upright post of dust remover box body wallboard-upright post structure system | |
| CN102787650B (en) | Support with denitration steel structure | |
| CN113090018A (en) | Construction method of super-thick overweight radiation-proof concrete cast-in-place beam slab formwork support system | |
| CN202767579U (en) | Support in denitration steel structure | |
| CN108487539B (en) | Perforated oblique seam type steel plate shear wall and application thereof | |
| CN206000025U (en) | A kind of dust collector box body | |
| KR20150114613A (en) | Evaluation method for reliable seismic performance factor of Diagrid structural system using test data | |
| CN111783206B (en) | Method for judging instability mode of steel plate shear wall based on stiffening rib threshold rigidity | |
| CN110975439B (en) | Method for improving stability of upright post of wall plate-upright post structure system of dust remover box body | |
| CN115688277B (en) | Bridge crane box girder web buckling analysis and calculation method | |
| CN214194634U (en) | Air cooling platform frame bearing structure system | |
| CN117932718A (en) | Determination method for local buckling critical stress of corrugated composite wall outer layer steel plate under compression | |
| Laier | An improved continuous medium technique for structural frame analysis | |
| Li et al. | Analysisof Effective Length Factors of Hinged Pitched-Roof Framed Column with Sway under Arch Effect | |
| Pan et al. | Influence of Stressed Skin Effect on the Bearing Capacity of Electrostatic Precipitator Casing Wall | |
| Hara | Behaviour of R/C Cooling Tower Shell Under Uneven Foundation Settlement | |
| Dat et al. | Parametric study on shear lag effect in super high-rise buildings using framed tube system |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20211224 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |