CN117057023A - Unified calculation length determining method for space steel structural members - Google Patents
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Abstract
The invention relates to a method for determining the unified calculation length of a space steel structural member, which comprises the following steps: the first step: establishing a whole structure finite element model of a space steel structure; and a second step of: applying boundary conditions and loads of various working conditions to the integral structure; and a third step of: establishing a local coordinate system at the end part of the component i, and calculating to obtain an elasto-analytical static solution of the component i; fourth step: performing eigenvalue analysis, and outputting eigenvalues and eigenvectors of the previous m-order buckling modes; fifth step: obtaining buckling modes meeting the discrimination requirements, outputting corresponding characteristic values, and solving the converted slenderness ratio of the obtained member; sixth step: repeating the processes from the third step to the fifth step to obtain the conversion slenderness ratio of all the components; seventh step: and obtaining the calculated length by the converted slenderness ratio. The method can obtain buckling critical load which accords with displacement function theory in classical stability theory, can directly solve by using a numerical method, and can conveniently obtain the calculated length of the component based on the buckling critical load.
Description
Technical Field
The invention relates to the technical field of structural design calculation, in particular to a method for determining the unified calculation length of a spatial steel structure member.
Background
In the current design method, the calculated length of the component is taken into account by using an empirical value or a simplified calculation method, the influence of the rigidity of the adjacent component is considered, and the method is more feasible to use in the simple structural design of the high-rise structure and the like, and the result can meet the engineering requirement. However, when the technology is applied to a complex space structure system, the influence of the rigidity of the whole structure on the component cannot be well considered, and the problem of the calculated length of the component is difficult to accurately solve, so that the related simplified calculated length coefficient is provided.
The method suggested in the prior study can only solve the characteristic value of a single component under the action of axial force when no external load and boundary conditions exist in the structure, and basically only considers the elastic buckling critical load of the component when the constraint effect of the adjacent component is considered, but ignores the influence of the external load on the buckling critical load of the component, has a gap with the buckling critical load which should embody the stability theory of the buckling critical load of the component, the displacement function of the component under the current load and the constraint conditions, and has no such requirement in the current design specification and provides a specific guiding method.
Disclosure of Invention
Aiming at the defect of the knowledge of the problems in the prior art, the patent provides a direct solving method for solving the problem of the calculated length of the component so that the expected buckling critical load accords with the displacement function-based theory in the classical stability theory, and the method can directly solve the problem by using a numerical method, and the calculated length of the component can be conveniently obtained based on the method so as to meet engineering application.
The invention is realized in the following way: a unified calculation length determining method for space steel structural members comprises the following steps: the first step: establishing a finite element model of the whole structure of the space steel structure, determining the initial configuration of each component, and simultaneously establishing a component array X [ i ], wherein i is the number of the component, the range of i is 1-n, and n is the total number of the components; and a second step of: according to the structural design scheme, boundary conditions and various working condition loads are applied to the whole structure; and a third step of: establishing a local coordinate system at the end part of the component i, applying unit axial force to the two ends of the component i under the local coordinate system, and calculating to obtain an elastic analysis static solution of the component i; fourth step: performing eigenvalue analysis on the basis of elastic analysis static solution, and outputting eigenvalue and eigenvector of the previous m-order buckling mode; fifth step: traversing the characteristic values and the characteristic vectors of all m-order buckling modes to obtain buckling modes meeting the discrimination requirements, outputting the corresponding characteristic values, and solving to obtain the conversion slenderness ratio of the component; sixth step: repeating the processes from the third step to the fifth step to obtain the conversion slenderness ratio of all the components; seventh step: and obtaining the calculated length by the converted slenderness ratio. According to the method for determining the unified calculation length of the spatial steel structural member, provided by the invention, the load effect and the boundary condition effect are considered, the relation between the buckling critical load of the member and the displacement function of the member under the current load effect is embodied in the fundamental principle, the constraint effect of the member when the integral structure works together is considered, the buckling critical load obtained accords with the displacement function-based theory in the classical stability theory, and the buckling critical load can be directly solved by using a numerical method, so that the requirements of engineering application are met.
In some embodiments, in the first step, the component array X [ i ] includes a component number and a unit number, and a correspondence relationship between the component number and the unit number is established. By establishing a corresponding relation, the components are ordered, the subsequent indexing of a plurality of rod pieces is facilitated, for example, the component number a of the component unit with the largest deformation is obtained, and if a=i, the component with the largest deformation is judged to be the component with the unit axial force.
In some embodiments, in the second step: the application of the boundary conditions comprises the determination of the boundary conditions of the support and the release conditions of the beam end according to the actual supporting form of the structure; the load applied under various working conditions comprises gravity load and various external force loads. By applying boundary conditions and loads under various working conditions, load action and boundary condition influence are considered in solving calculation, compared with the traditional theory that only the elastic buckling critical load of the component when the constraint effect of the adjacent component is considered, but compared with the influence of the external load action on the buckling critical load of the component, the relation between the buckling critical load of the component and the displacement function of the component under the current load action is reflected, meanwhile, the constraint effect of the component when the integral structure works together is considered, the obtained buckling critical load is more practical, and the requirements of engineering application are met.
In some embodiments, in the third step, the calculating the elastometric static solution for component i comprises: (1) Calculating an elastic second-order analysis static solution, setting the solution as a geometric nonlinear solving process, and calculating to obtain geometric nonlinear elastic deformation and internal force of the component i; or (2) calculating an elastic first-order analysis static solution, setting the solution as a geometric linear solving process, and calculating to obtain geometric linear elastic deformation and internal force of the component i. According to the calculation method, according to specific conditions and analysis requirements, two elastic analysis static solutions of the component can be calculated respectively, namely, for nonlinear solution of a space structure with a displacement boundary, an elastic second-order analysis static solution can be calculated, for linear solution of a space structure with a displacement boundary, an elastic first-order analysis static solution can be calculated, and further, geometric nonlinearity or linear elastic deformation and internal force of the component can be calculated, so that the method has better universality and universality.
In some embodiments, in the fifth step, the obtaining the buckling mode meeting the discrimination requirements specifically includes: and starting from the 1 st-order buckling mode, judging whether the buckling modes meet the judging requirements, if so, outputting a characteristic value to solve the conversion slenderness ratio, if not, sequentially checking whether the remaining 2-m-order buckling modes meet the judging requirements, when the buckling modes meeting the judging requirements are not found after all the m-order buckling modes are traversed, increasing the buckling mode output order m, re-carrying out characteristic value solving, continuing to traverse all the buckling modes until the buckling modes meeting the judging requirements are found, and outputting the characteristic value to solve the conversion slenderness ratio. By starting from the 1 st-order (j=1) buckling mode, searching for buckling modes meeting the discrimination requirements, traversing all m-order buckling modes if necessary, so as to quickly find buckling modes meeting the discrimination requirements, and outputting characteristic values to solve the conversion slenderness ratio.
In some embodiments, the discriminating requirement is to determine whether the deformation maximum member is the aforementioned unit axial force applying member. Each stage of buckling mode has a deformation maximum component, and only when the deformation maximum component is the unit axial force applying component, the load of the stage of buckling mode is the buckling critical load of the component, but most of the time, the maximum deformation does not necessarily occur on the unit axial force applying component, so that the condition is used as a condition for searching the buckling mode meeting the judging requirement, all modes are traversed, and the buckling mode meeting the judging requirement can be truly obtained.
In some embodiments, the determining whether the deformation maximum member is the aforementioned unit axial force applying member includes: extracting the unit number of the unit of the maximum member of the j-th order buckling mode deformation in finite element software; and obtaining the component number a of the component unit with the largest deformation according to the corresponding relation between the unit number and the component number in the component array X [ i ], and judging the component with the largest deformation as the component applying the unit axial force when a=i. Through the previously established component array X [ i ], and the corresponding relation between the unit number and the component number is already established, the component number a of a unit of the unit can be obtained by only extracting the unit number of the unit of the maximum deformation component, and whether the unit of the maximum deformation component is the component for applying the unit axial force can be easily obtained by identifying whether a=i is established.
In some embodiments, after finding the buckling mode meeting the discrimination requirements, the method further includes: and judging that the current component i is less than or equal to n, if so, continuing to execute the third step again, calculating the next component i+1, and if not, outputting the conversion slenderness ratio of all the components. Through the link, whether the converted slenderness ratio of the residual components is not obtained at present is judged, namely whether all the components are executed and the converted slenderness ratio is obtained is judged, so that incomplete calculation results caused by omission are avoided, and the slenderness ratio of a part of rod pieces is avoided.
In some embodiments, in the fifth step, the solving the output eigenvalue to obtain a scaled slenderness ratio of the member includes: taking the characteristic value corresponding to the output as the buckling critical load N of the component cr And calculating the converted slenderness ratio of the component by the following method: 1) When boundary conditions at two ends of the component are simply supported, euler load and slenderness ratio of the component i are calculated:
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；
；
；
2) Calculating the converted slenderness ratio lambda of the component 0 ：
；
；
；
Wherein mu is calculated length coefficient, and 1/l is calculated simply at two ends of the component 0 To calculate the length, i is the geometric length of the component between its effective constraint points, i is the radius of gyration, λ, of the component cross-section 0 To convert slenderness ratio, N cr For critical load of buckling, N E Is Euler load, namely buckling critical load of the elastic axial compression component, E is elastic modulus, A is component sectional area and N E hinge For Euler load, lambda, when the two ends of the member are simply supported Hinge Is the slenderness ratio when the two ends of the component are simply supported.
The traditional method obtains the calculated length through introducing the calculated length coefficient conversion, and the calculated length coefficient cannot be accurately determined because the boundary condition is complex in the actual engineering. According to the method, the buckling critical load of the axial compression member is obtained through calculation, and then the conversion slenderness ratio of the thrust member bypasses the calculation length coefficient, so that each load value is easy to obtain, and compared with a calculation method, the method is more direct and easier, and has good operability.
In some embodiments, further comprising: eighth step: outputting all the component conversion slenderness ratios to a file.
Compared with the prior art, the invention has the beneficial effects that: the calculation length is a necessary parameter for calculating the buckling critical load of the component, namely the calculation length is needed to be determined firstly. In particular, at least the following benefits are obtained:
(1) According to the invention, boundary conditions and loads of various working conditions are applied to the structure, and the calculated length of the component in the current displacement state under the action of different loads or load combinations is considered; and obtaining the calculated length considering the first-order effect for linear solution and obtaining the calculated length considering the second-order effect for nonlinear solution.
(2) For linear solution, an accurate finite element implementation method of the linear buckling critical load of each component in the complex structure is determined; for nonlinear solution, an accurate finite element implementation method of nonlinear buckling critical load of each component in the complex structure is determined, and ideas and methods are provided for determining the accurate finite element implementation of the linear buckling critical load of the complex structure from geometric nonlinear solution (calculation length coefficient) to linear solution (buckling critical load).
(3) The recommended slenderness ratio calculation method is adopted, and the conversion slenderness ratio of the buckling critical load thrust member based on the axial compression member bypasses various uncertainties and inaccuracy caused by the adoption of the calculation length coefficient in the traditional method.
It should be understood that the implementation of any of the embodiments of the invention is not intended to simultaneously possess or achieve some or all of the above-described benefits.
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 will be apparent to those skilled in the art from this disclosure that the drawings described below are merely exemplary and that other embodiments may be derived from the drawings provided without undue effort.
The structures, proportions, sizes, etc. shown in the present specification are shown only for the purposes of illustration and description, and are not intended to limit the scope of the invention, which is defined by the claims, but rather by the claims.
Fig. 1 illustrates a method flow diagram of one embodiment of the present invention.
Fig. 2 illustrates a method flow diagram of another embodiment of the present invention.
Like or corresponding reference characters indicate like or corresponding parts throughout the several views.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the present invention will be described in further detail with reference to the embodiments and the accompanying drawings. The exemplary embodiments of the present invention and their descriptions herein are for the purpose of explaining the present invention, but are not to be construed as limiting the invention.
In the description of the present invention, the terms "comprises/comprising," "consists of … …," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a product, apparatus, process, or method that comprises a list of elements does not include only those elements but may, if desired, include other elements not expressly listed or inherent to such product, apparatus, process, or method. Without further limitation, an element defined by the phrases "comprising/including … …," "consisting of … …," and the like, does not exclude the presence of other like elements in a product, apparatus, process, or method that includes the element.
It is to be understood that unless specifically stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
It should be further understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," "center," and the like are used in an orientation or positional relationship based on that shown in the drawings, merely to facilitate describing the present invention and to simplify the description, and do not indicate or imply that the devices, components, or structures referred to must have a particular orientation, be constructed or operated in a particular orientation, and are not to be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance, or as implying a limitation on the number of technical features indicated, or on the order of precedence. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
The invention aims to research a direct calculation method for unifying the calculation length of a member on the basis of considering geometrical nonlinearity or linearity under the action of axial force, bending moment and torque when considering the influence of load action and boundary conditions when researching the stable calculation of a building steel structural member. Compared with the traditional calculation length analysis theory, the characteristic value of a single component under the action of axial force can only be solved when no external load acts in the structure, and the elastic buckling critical load of the component when the restraint effect of the adjacent component is considered basically, but the influence of the external load on the buckling critical load of the component is ignored. From classical stability theory, it is known that in this theory, the buckling critical load is a characteristic value of the buckling displacement function, and one buckling critical load corresponds to one displacement function, and if the displacement function is accurate, the buckling critical load calculated by the displacement function is unique and accurate. The method embodies the relation between the buckling critical load of the component and the displacement function of the component under the action of the current load from the root principle, and simultaneously takes into account the constraint action of the component when the integral structure works together, so that the buckling critical load obtained by the method accords with the displacement function-based theory in the classical stability theory, can be directly solved by using a numerical method, and meets the requirements of engineering application.
The implementation of the present invention will be described in detail with reference to the preferred embodiments.
With reference to flowcharts shown in fig. 1 and fig. 2, an execution process of a method for determining a uniform calculation length of a spatial steel structural member is presented, and each link is specifically described below.
The first step: and establishing a finite element model of the whole structure of the space steel structure, determining the initial configuration of each component, and simultaneously establishing a component array X [ i ], wherein i is the number of the component, the range of i is 1-n, and n is the total number of the components.
In this embodiment, the finite element model does not include a sling for lifting the spatial steel structural member, and the cable is a nonlinear unit, and its specificity may affect the displacement function.
Finite element modeling may employ finite element analysis software commonly used in the industry, such as ABAQUS/ANSYA/ADINA, etc.
In this step, the initial configuration of each component is given by the design drawing.
In the present invention, the so-called "member" may be, for example, a common rod member including various rod members in a spatial steel structure.
In the finite element model, one rod may be divided into a plurality of units, for example, the rod 1 is divided into 4 units, the unit numbers are 11, 12, 13 and 14, and the study object for calculating the length coefficient is a rod rather than a unit, so that while the finite element model is built, a rod array X [ i ] is built, the rod array X [ i ] comprises a rod number and a unit number, and the corresponding relation between the rod number and the unit number is built, wherein i is the rod number, the range of i is 1-n, and n is the total number of rods. The components are ordered through the rod piece array, so that the subsequent indexing of a plurality of rod pieces is facilitated.
And a second step of: according to the structural design scheme, boundary conditions and various working condition loads are applied to the whole structure.
In this step, applying the boundary conditions includes determining the abutment boundary conditions, beam end release conditions, such as rigid connection, articulation, depending on the actual form of support of the structure; the load applied under various working conditions comprises gravity load and various external force loads.
And a third step of: and establishing a local coordinate system at the end part of the component i, applying unit axial force to the two ends of the component i under the local coordinate system, and calculating to obtain an elasto-analytical static solution of the component i.
The local coordinate system is, for example, in the x-axis along the width of the cross-section of the member, in the y-axis along the height of the cross-section of the member, and in the Z-axis along the length of the member.
In the step, according to specific conditions and analysis requirements, the elasto-analytical static solution of the component i is calculated and obtained by the following two conditions:
(1) For nonlinear solution of a space structure with a displacement boundary, calculating an elastic second-order analysis static solution, setting the solution as a geometric nonlinear solution process, and calculating to obtain geometric nonlinear elastic deformation and internal force of the component i;
(2) And (3) for linear solution of the space structure with the displacement boundary, calculating an elastic first-order analysis static solution, setting the solution as a geometric linear solution process, and calculating to obtain geometric linear elastic deformation and internal force of the component i.
Fourth step: and carrying out eigenvalue analysis on the basis of elastic analysis static solution, and outputting eigenvalue and eigenvector of the previous m-order buckling mode.
And re-entering a solver, and setting the solving type as a eigenvalue solving. And calculating the characteristic values of the internal force and deformation of the steel structure based on the calculation result of the last step.
During buckling analysis, the characteristic value and the characteristic vector are both calculation results of characteristic value solution during buckling analysis of finite element software, and the characteristic value is buckling critical load N cr The eigenvector is the buckling mode deformation. In theory, the number of the eigenvalues and the length of the displacement matrix are equal, a plurality of eigenvalue calculation results are output according to the structural characteristics, and only a part of the eigenvalue calculation results, namely the first m steps, are selected to be output in the step, so that the calculation resources are saved.
Fifth step: traversing the eigenvalues and eigenvectors of all m-order buckling modes to obtain buckling modes meeting the discrimination requirements, outputting corresponding eigenvalues, and solving according to the eigenvalues to obtain the conversion slenderness ratio of the component.
In this step, with continued reference to fig. 2, the buckling mode that meets the discrimination requirements is specifically executed as follows:
starting from a 1 st-order (j=1) buckling mode, judging whether the buckling mode meets the judging requirement, if so, outputting a characteristic value to solve a conversion slenderness ratio, if not, sequentially checking whether the remaining 2-m-order buckling modes meet the judging requirement, when the buckling mode meeting the judging requirement is not found after all m-order buckling modes are traversed, increasing the buckling mode output order m, re-carrying out characteristic value solving, continuing traversing all the buckling modes until the buckling mode meeting the judging requirement is found, and outputting the characteristic value to solve the conversion slenderness ratio.
In this embodiment, whether the discrimination requirements are met is defined as: and judging whether the deformation maximum component is the component applying the unit axial force.
Since the maximum deformation does not necessarily occur on the member to which the unit axial force is applied many times, it is necessary to make a judgment that only the buckling mode and load occurring on the member are the buckling critical loads of the member, and it is necessary to traverse all the modes to judge whether the deformation maximum member is the aforementioned member to which the unit axial force is applied.
Specifically, determining whether or not the deformation maximum member is the aforementioned unit axial force applying member includes:
extracting the unit number of the unit of the maximum member of the j-th order buckling mode deformation in finite element software;
and obtaining the component number a of the component unit with the largest deformation according to the corresponding relation between the unit number and the component number in the component array X [ i ], and judging the component with the largest deformation as the component applying the unit axial force when a=i.
In the invention, after the buckling mode meeting the discrimination requirement is found, the method continues to execute:
and judging whether the current component i is less than or equal to n, namely whether the conversion slenderness ratio of the residual components is not obtained currently, if so, continuing to execute the third step again, calculating the next component i+1, and if not, outputting the conversion slenderness ratio of all the components.
In this step, the conversion slenderness ratio of the member obtained by solving the output characteristic value includes:
and calculating the conversion slenderness ratio of the component by taking the output characteristic value as the buckling critical load of the component.
The slenderness ratio is related to the radius of gyration of the cross section, which is an inherent attribute of the cross section and is not changed along with the change of the boundary condition of the component, and the calculated length; calculated length = calculated length coefficient x geometric length, wherein calculated length coefficient is related to boundary conditions at both ends of the component, so the key to determining slenderness ratio is to determine calculated length coefficient. In actual engineering, boundary conditions are often complex, and boundary conditions at two ends of a component cannot be simply determined, so that the calculated length coefficient cannot be accurately determined.
The invention recommends a slenderness ratio calculation method: the buckling critical load of the axial compression member is calculated firstly, and then the conversion slenderness ratio of the thrust reverser member is calculated. The method comprises the following steps:
the output characteristic value is taken as the buckling critical load N of the component cr And calculating the converted slenderness ratio of the component by the following method:
1) Calculating slenderness ratio and Euler load of the component i when boundary conditions at two ends of the component are simply supported:
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2) Calculating the converted slenderness ratio lambda of the component 0 ：
；
；
；
Wherein mu is calculated length coefficient, and 1/l is calculated simply at two ends of the component 0 To calculate the length, i is the geometric length of the component between its effective constraint points, i is the radius of gyration, λ, of the component cross-section 0 To convert slenderness ratio, N cr For critical load of buckling, N E Is Euler load, namely buckling critical load of the elastic axial compression component, E is elastic modulus, A is component sectional area and N E hinge For Euler load, lambda, when the two ends of the member are simply supported Hinge Length of member simply supported at two endsFine ratio.
Sixth step: and repeating the processes from the third step to the fifth step to obtain the conversion slenderness ratio of all the components.
Seventh step: the calculated length is obtained by converting the slenderness ratio. The method comprises the following steps:
；
wherein, I 0 To calculate the length lambda 0 In order to convert the slenderness ratio, i is the radius of gyration of the member cross section.
Eighth step: outputting all the component conversion slenderness ratios to a file.
From the above description, the invention is based on classical stability theory, and the relation between the buckling critical load of the component and the displacement function of the component under the current load is embodied in the fundamental principle, and meanwhile, the constraint effect of the component when the integral structure works together is considered, the buckling critical load is in line with the displacement function-based theory in classical stability theory, and can be directly solved by using a numerical method, thereby meeting the requirements of engineering application.
The foregoing description of embodiments of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the technical improvements in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
While several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the invention. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination.
Claims (10)
1. The unified calculation length determining method for the space steel structural member is characterized by comprising the following steps of:
the first step: establishing a finite element model of the whole structure of the space steel structure, determining the initial configuration of each component, and simultaneously establishing a component array X [ i ], wherein i is the number of the component, the range of i is 1-n, and n is the total number of the components;
and a second step of: according to the structural design scheme, boundary conditions and various working condition loads are applied to the whole structure;
and a third step of: establishing a local coordinate system at the end part of the component i, applying unit axial force to the two ends of the component i under the local coordinate system, and calculating to obtain an elastic analysis static solution of the component i;
fourth step: performing eigenvalue analysis on the basis of elastic analysis static solution, and outputting eigenvalue and eigenvector of the previous m-order buckling mode;
fifth step: traversing the characteristic values and the characteristic vectors of all m-order buckling modes to obtain buckling modes meeting the discrimination requirements, outputting the corresponding characteristic values, and solving to obtain the conversion slenderness ratio of the component;
sixth step: repeating the processes from the third step to the fifth step to obtain the conversion slenderness ratio of all the components;
seventh step: and obtaining the calculated length by the converted slenderness ratio.
2. The method according to claim 1, wherein in the first step, the component array X [ i ] includes a component number and a unit number, and a correspondence relationship between the component number and the unit number is established.
3. The method according to claim 1, wherein in the second step:
the application of the boundary conditions comprises the determination of the boundary conditions of the support and the release conditions of the beam end according to the actual supporting form of the structure;
the load applied under various working conditions comprises gravity load and various external force loads.
4. The method according to claim 1, wherein in the third step, the calculating a elasto-analytical static solution for component i comprises:
(1) Calculating an elastic second-order analysis static solution, setting the solution as a geometric nonlinear solving process, and calculating to obtain geometric nonlinear elastic deformation and internal force of the component i; or (b)
(2) And calculating an elastic first-order analysis static solution, setting the solution as a geometric linear solving process, and calculating to obtain geometric linear elastic deformation and internal force of the component i.
5. The method according to claim 1, wherein in the fifth step, the obtaining a buckling mode meeting the discrimination requirements specifically includes:
and starting from the 1 st-order buckling mode, judging whether the buckling modes meet the judging requirements, if so, outputting a characteristic value to solve the conversion slenderness ratio, if not, sequentially checking whether the remaining 2-m-order buckling modes meet the judging requirements, when the buckling modes meeting the judging requirements are not found after all the m-order buckling modes are traversed, increasing the buckling mode output order m, re-carrying out characteristic value solving, continuing to traverse all the buckling modes until the buckling modes meeting the judging requirements are found, and outputting the characteristic value to solve the conversion slenderness ratio.
6. The method according to claim 5, wherein:
the determination is made as to whether or not the deformation maximum member is the aforementioned unit axial force application member.
7. The method of claim 6, wherein the determining whether the deformation maximum member is the aforementioned unit axial force applying member comprises:
extracting the unit number of the unit of the maximum member of the j-th order buckling mode deformation in finite element software;
and obtaining the component number a of the component unit with the largest deformation according to the corresponding relation between the unit number and the component number in the component array X [ i ], and judging the component with the largest deformation as the component applying the unit axial force when a=i.
8. The method of claim 5, wherein after finding the buckling mode meeting the discrimination requirements, further comprising:
and judging that the current component i is less than or equal to n, if so, continuing to execute the third step again, calculating the next component i+1, and if not, outputting the conversion slenderness ratio of all the components.
9. The method according to claim 1, wherein in the fifth step, the solving the output eigenvalue to obtain a converted slenderness ratio of the member includes:
the output characteristic value is taken as the buckling critical load N of the component cr And calculating the converted slenderness ratio of the component by the following method:
1) Calculating slenderness ratio and Euler load of the component i when boundary conditions at two ends of the component are simply supported:
；
；
；
；
2) Calculating the converted slenderness ratio lambda of the component 0 ：
；
；
；
Wherein mu is calculated length coefficient, and 1/l is calculated simply at two ends of the component 0 To calculate the length, i is the geometric length of the component between its effective constraint points, i is the radius of gyration, λ, of the component cross-section 0 To convert slenderness ratio, N cr For critical load of buckling, N E Is Euler load, namely buckling critical load of the elastic axial compression component, E is elastic modulus, A is component sectional area and N E hinge For Euler load, lambda, when the two ends of the member are simply supported Hinge Is the slenderness ratio when the two ends of the component are simply supported.
10. The method as recited in claim 1, further comprising:
eighth step: outputting all the component conversion slenderness ratios to a file.
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