Dynamic stability analysis method of connected latticed shell structure under earthquake action

Abstract

The invention relates to the technical field of building structures, and provides a method for analyzing the dynamic stability of a connected latticed shell structure under the action of an earthquake, comprising the following steps: establishing an analysis model of the connected latticed shell structure, at least one end of the analysis model being a loading end; a displacement effect is applied to the loading end in the target direction, single nonlinear static analysis and double nonlinear static analysis are carried out on the analysis model, and whether the connected latticed shell structure has an overall instability failure mode in the target direction or not is judged; selecting seismic waves to carry out elastic time-history analysis or elastic-plastic time-history analysis on the overall structure according to the target intensity, and obtaining displacement time-history data of a loading end; and performing double-nonlinear displacement loading power time-history analysis on the loading end by using the displacement time-history data until the connected latticed shell structure is subjected to instability failure, and obtaining latticed shell power instability critical internal force or latticed shell power instability critical displacement of the connected latticed shell structure. The method can solve the problem that a method for analyzing the dynamic stability of the connected latticed shell structure under the earthquake action is lacked.

Description

Technical Field

[0001] The invention relates to the technical field of building structures, in particular to a method for analyzing the dynamic stability of a connected lattice shell structure under earthquake action. Background Art

[0002] The stability problem is a controlling factor in the design of single-layer lattice shell structures. Conventional single-layer lattice shell structures either form a single structural unit independently or are attached to a single lower structure. The loads during stability analysis are mainly static conditions such as vertical loads, wind loads, and temperature loads. The internal forces generated in horizontal earthquakes generally do not cause the overall stability of single-layer lattice shells to be destroyed, and generally single-layer lattice shell structures do not need to be analyzed for overall stability under horizontal earthquakes.

[0003] The most significant difference between the connected single-layer lattice shell and the conventional single-layer lattice shell is that the supports of the connected single-layer lattice shell are distributed on two independent structural monomers. As a result, on the one hand, the single-layer lattice shell as a connector will coordinate the lateral deformation of the structural units at both ends, thereby affecting the dynamic characteristics of the structural units at both ends. On the other hand, the structural units with different dynamic characteristics at both ends are not completely synchronized during an earthquake, which will cause horizontal compression, stretching, dislocation and other effects on the connected single-layer lattice shell. These effects caused by earthquakes are all dynamic loads. For connected lattice shells, these effects cannot be ignored and require special analysis. However, the existing technology lacks an analysis method for the dynamic stability of connected lattice shell structures, so it is impossible to judge the dynamic stability of connected lattice shell structures. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that the prior art lacks a method for analyzing the dynamic stability of a connected lattice shell structure under earthquake action, thereby being unable to judge the dynamic stability of the connected lattice shell structure, and to provide a method for analyzing the dynamic stability of a connected lattice shell structure under earthquake action.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for dynamic stability analysis of a connected lattice shell structure under earthquake action comprises the following steps:

[0007] An analysis model of a conjoined lattice shell structure is established, with at least one end of the analysis model being a loading end; a displacement action is applied in a target direction of the loading end, and single nonlinear static analysis and double nonlinear static analysis are performed on the analysis model, and it is determined whether the conjoined lattice shell structure has an overall instability failure mode in the target direction according to the analysis results;

[0008] When the connected lattice shell structure has an overall instability failure mode in the target direction, the target intensity seismic wave is selected to perform elastic time history analysis or elastoplastic time history analysis on the overall structure to obtain the displacement time history data of the loading end and the maximum total internal force of the connected lattice shell structure or the maximum relative displacement of the supports at both ends of the connected lattice shell structure under the target intensity earthquake; the displacement time history data is used to perform a double nonlinear displacement loading dynamic time history analysis on the loading end until the connected lattice shell structure is unstable and destroyed, and the critical internal force of dynamic instability of the lattice shell structure or the critical displacement of dynamic instability of the lattice shell structure is obtained; the dynamic stability of the connected lattice shell structure in the target direction is judged based on the critical internal force of dynamic instability of the lattice shell or the critical displacement of dynamic instability of the lattice shell.

[0009] The structure of the analysis model, such as the distribution of supports and rods, should match the actual structure of the connected lattice shell structure and be able to meet the requirements of static analysis; the setting of the loading end depends on the actual situation. Taking the connected lattice shell structure with two ends as an example, one end can be set as the fixed end and the other end as the loading end; or both ends can be set as loading ends.

[0010] The target direction should cover as much as possible all possible deformation modes of the connected lattice shell structure, such as compression, stretching and displacement along the horizontal direction.

[0011] The overall instability failure mode can be determined by the single nonlinear and double nonlinear displacement-load curves of the connected lattice shell structure.

[0012] When selecting seismic waves, the seismic waves that meet the wave selection requirements of the structural units at both loading ends should be selected according to the seismic codes, such as the requirements in Article 5.1.2 of the Code for Seismic Design of Buildings (2016 Edition) (GB50011-2010).

[0013] In dual nonlinear static analysis and dual nonlinear displacement loading dynamic time history analysis, dual nonlinear refers to the simultaneous consideration of material nonlinearity and geometric nonlinearity; in single nonlinear static analysis, single nonlinear refers to the consideration of only material nonlinearity.

[0014] This scheme simultaneously performs single nonlinear static analysis and double nonlinear static analysis on the analysis model in the target direction. When it is judged that the connected grid shell structure has an overall instability failure mode in the target direction according to the analysis results, the overall structure is subjected to elastic time history analysis or elastoplastic time history analysis using seismic waves, thereby obtaining the displacement time history data of the loading end and the maximum total internal force of the connected grid shell structure under the target earthquake intensity and the maximum relative displacement of the supports at both ends. The displacement time history data is then used to perform double nonlinear displacement loading dynamic time history analysis on the loading end until the connected grid shell structure is unstable and destroyed. The critical internal force of dynamic instability of the grid shell or the critical displacement of dynamic instability of the grid shell can be obtained during the analysis process. By comparing the critical internal force of dynamic instability of the grid shell with the maximum total internal force that the connected grid structure has to bear during an earthquake, or by comparing the critical displacement of dynamic instability of the grid shell with the maximum relative displacement that the connected grid structure can produce during an earthquake, the dynamic stability and safety margin of the connected grid shell structure in the target direction during an earthquake can be determined.

[0015] As a preferred embodiment of the present invention, the method further comprises the following steps:

[0016] Perform elastic time history analysis or elastoplastic time history analysis on the analysis model under the target level earthquake to obtain the maximum total internal force or maximum relative displacement of the connected lattice shell structure; judge the dynamic stability of the connected lattice shell structure in the target direction according to the ratio of the critical internal force of dynamic instability of the lattice shell to the maximum total internal force, or judge the dynamic stability and safety margin of the connected lattice shell structure in the target direction according to the ratio of the critical displacement of dynamic instability of the lattice shell to the maximum relative displacement.

[0017] The specific parameters of the target level earthquake are determined according to the seismic requirements of the connected lattice shell structure.

[0018] This scheme recommends judging the dynamic stability and safety margin of the connected lattice shell structure in the target direction by the ratio of the critical internal force of the lattice shell dynamic instability to the maximum total internal force, or the ratio of the critical displacement of the lattice shell dynamic instability to the maximum relative displacement. This can quantitatively analyze the stability of the connected lattice shell structure. The larger the ratio, the higher the safety factor of the connected lattice shell structure.

[0019] As a preferred embodiment of the present invention, when there are extreme points in the load-displacement curve of the dual nonlinear static analysis and the load-displacement curve of the dual nonlinear static analysis is lower than the load-displacement curve of the single nonlinear static analysis as a whole, it is judged that the connected lattice shell structure has an overall unstable failure mode in the target direction.

[0020] This scheme recommends specific judgment criteria for determining whether a connected lattice shell structure has an overall instability failure mode in the target direction. The results can be obtained simply and quickly by observing the load-displacement curve, thereby improving the analysis efficiency.

[0021] As a preferred solution of the present invention, when performing dual nonlinear displacement loading dynamic time history analysis, the maximum displacement loaded at the loading end is gradually increased from a value lower than the static critical instability displacement of the lattice shell.

[0022] Increase step by step, such as linear increase or proportional increase.

[0023] This scheme recommends that the maximum displacement loaded at the loading end be increased step by step until the connected lattice shell structure becomes unstable and fails. It is suitable for situations where it is necessary to accurately obtain the critical displacement and critical internal force of the lattice shell dynamic instability.

[0024] As a preferred solution of the present invention, the kth level maximum displacement is a times the static critical instability displacement of the lattice shell, k=1, 2, 3..., a=k / 10.

[0025] This scheme recommends a specific way to increase the maximum displacement loaded at the loading end, that is, the first-level displacement is 10% of the static critical instability displacement of the lattice shell, the second-level displacement is 20% of the static critical instability displacement of the lattice shell, and the third-level displacement is 30% of the static critical instability displacement of the lattice shell... The value increased at each level is equal to 10% of the static critical instability displacement of the lattice shell until the connected lattice shell structure becomes unstable and fails.

[0026] As a preferred solution of the present invention, the maximum total internal force of the connected lattice shell structure under the first level maximum displacement is F 1 , the maximum total internal force of the connected lattice shell structure under the kth maximum displacement is F k , the maximum total internal force of the connected lattice shell structure under the k+1th maximum displacement is F k+1 , when F k+1 -F k <F 1 *5%, the kth maximum displacement is taken as the critical displacement of dynamic instability of lattice shell, and the kth maximum total internal force is taken as the critical internal force of dynamic instability of lattice shell.

[0027] This proposal recommends the basis for judging whether a conjoined lattice shell structure has suffered instability failure.

[0028] As a preferred solution of the present invention, when performing dual nonlinear displacement loading dynamic time history analysis, the maximum displacement loaded at the loading end is greater than or equal to 1.5 times the static critical instability displacement of the lattice shell.

[0029] The static critical instability displacement of lattice shells can be obtained through the load-displacement curves of single nonlinear static analysis and double nonlinear static analysis.

[0030] This scheme recommends a specific range of maximum displacements loaded at the loading end, which can ensure that the connected lattice shell structure will not be unstable and damaged under the action of dynamic loads. It is suitable for situations where the critical internal force of dynamic instability of the lattice shell needs to be quickly obtained.

[0031] As a preferred embodiment of the present invention, the number of selected seismic waves is greater than one, and multiple displacement time-history data, multiple maximum total internal forces of connected lattice shell structures and multiple maximum relative displacements of supports at both ends of the connected lattice shell structures are obtained, thereby obtaining multiple critical internal forces for dynamic instability of the lattice shells or multiple critical displacements for dynamic instability of the lattice shells; the ratio of the average value of the critical internal forces for dynamic instability of the lattice shells to the average value of the maximum total internal forces is used as the basis for judgment, or the ratio of the average value of the critical displacements for dynamic instability of the lattice shells to the average value of the maximum total internal forces is used as the basis for judgment.

[0032] This scheme recommends using multiple seismic waves to obtain multiple critical internal forces or multiple critical displacements of dynamic instability of lattice shells, and then calculating the average value, which is then compared with the average value of the maximum total internal force and the average value of the maximum relative displacement as the basis for subsequent judgment. On the one hand, the results of this scheme can cover a variety of situations where different seismic waves act, and on the other hand, it can also reduce the errors and deviations of the critical internal force results or the critical displacement results of dynamic instability of lattice shells.

[0033] As a preferred embodiment of the present invention, when static analysis applies displacement, the ground displacement is zero, the displacement of the support with the highest elevation at the loading end is one, and the displacements of the supports at the loading end are distributed in a linear difference along the height direction.

[0034] In this scheme, the displacement of the support with the highest elevation is one, and the displacement of the remaining supports decreases linearly from top to bottom until it is lowered to zero when the ground is lowered. The overall displacement distribution is an inverted triangle, which conforms to the actual situation, thus making the analysis results more accurate.

[0035] As a preferred embodiment of the present invention, when there is no overall instability failure mode of the connected lattice shell structure in the target direction, it is judged that the dynamic stability of the connected lattice shell structure in the target direction meets the requirements.

[0036] When there is no overall instability failure mode of the connected lattice shell structure in the target direction, the subsequent elastic time history analysis or elastoplastic time history analysis and dual nonlinear displacement loading dynamic time history analysis may not be performed.

[0037] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0038] 1. A method for analyzing the dynamic stability of a connected lattice shell structure under earthquake action of the present invention can obtain the critical internal force of dynamic instability of the lattice shell or the critical displacement of dynamic instability of the lattice shell, so as to judge the dynamic stability of the connected lattice shell structure in a target direction during an earthquake based on the critical internal force of dynamic instability of the lattice shell or the critical displacement of dynamic instability of the lattice shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1It is a schematic flow chart of a method for analyzing the dynamic stability of a connected lattice shell structure under earthquake action in Example 1;

[0040] Figure 2 is a schematic flow chart of a method for analyzing the dynamic stability of a connected lattice shell structure under earthquake action in Example 2;

[0041] Figure 3 It is a schematic diagram of the analytical model of the conjoined lattice shell structure;

[0042] Figure 4 It is a schematic diagram of the load-displacement curve obtained through double nonlinear static analysis and single nonlinear static analysis;

[0043] Figure 5 It is a schematic diagram of the total internal force distribution curve of the connected lattice shell structure under the action of different seismic waves; DETAILED DESCRIPTION

[0044] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0045] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0046] In the description of the following specific embodiments, the terms indicating the orientation or position relationship such as "upper", "lower", "left", "right", "center", "inside", "outside", etc. are all based on the expression of the orientation or position relationship shown in the drawings, or the orientation or position relationship when the device / apparatus is usually used. These terms of orientation or position relationship are only for the convenience of description or simplification of the description in the specific embodiments, so that technicians can quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation of the present invention.

[0047] The terms "horizontal", "vertical" and the like do not mean that the corresponding devices / components / elements are absolutely horizontal or vertical or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. Alternatively, it can be simply understood that the corresponding devices / components / elements are set in specific directions such as "horizontal" and "vertical", and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding devices / components / elements are within the error / deviation range, they can still achieve their functions in the scheme of the present invention. The terms "set", "install", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a connection means commonly used in the field such as welding, riveting, bolting, threaded connection, etc., it can be directly connected, it can also be indirectly connected through an intermediate medium, and it can be the internal connection of two elements.

[0048] Example 1

[0049] like Figure 1 As shown, a method for dynamic stability analysis of a connected lattice shell structure under earthquake action adopted in this embodiment comprises the following steps:

[0050] S1: Establish an analysis model of a conjoined lattice shell structure, where at least one end of the analysis model is a loading end;

[0051] S2: Apply displacement in the target direction of the loading end, and perform single nonlinear static analysis and double nonlinear static analysis on the analysis model. According to the analysis results, determine whether there is an overall instability failure mode of the connected lattice shell structure in the target direction;

[0052] S3: When the connected lattice shell structure has an overall instability failure mode in the target direction, select the target intensity seismic wave to perform elastic time history analysis or elastoplastic time history analysis on the overall structure to obtain the displacement time history data of the loading end, the maximum total internal force of the connected lattice shell structure under the target intensity, and the maximum relative displacement of the supports at both ends of the connected lattice shell structure;

[0053] S4: Use the displacement time history data to perform double nonlinear displacement loading dynamic time history analysis on the loading end until the connected lattice shell structure is unstable and damaged, and obtain the critical internal force or critical displacement of the lattice shell dynamic instability of the connected lattice shell structure;

[0054] S5: The dynamic stability of the connected lattice shell structure in the target direction is determined based on the critical internal force of the lattice shell dynamic instability or the critical displacement of the lattice shell dynamic instability.

[0055] Specifically, in step S1, this embodiment establishes the following according to the actual situation of the conjoined lattice shell structure and the requirements of static analysis: Figure 3 The finite element analysis model shown includes two left and right ends, wherein the left end is set as a fixed end and the right end is set as a loading end; by applying displacements in different directions to the loading end, different target directions can be analyzed. For example, for this embodiment, by applying a displacement from right to left to the loading end, the extrusion direction can be analyzed.

[0056] Furthermore, in step S2, when the displacement is applied, the ground displacement is zero, the displacement of the support with the highest elevation at the loading end is one, and the displacements of the supports at the loading end are distributed in a linear difference along the height direction.

[0057] Further, in step S2, when the load-displacement curve of the dual nonlinear static analysis has an extreme point, and the load-displacement curve of the dual nonlinear static analysis is lower than the load-displacement curve of the single nonlinear static analysis as a whole, it is determined that the conjoined lattice shell structure has an overall instability failure mode in the target direction. Specifically, Figure 4 As shown in the figure, curve CⅡ is the load-displacement curve of the double nonlinear static analysis, and curve CⅠ is the load-displacement curve of the single nonlinear static analysis. It can be seen that curve CⅡ has an extreme point, and the whole is located below curve CⅠ. Therefore, it is judged that the connected lattice shell structure of this embodiment has an overall unstable failure mode, and the displacement corresponding to the extreme value of curve CⅡ can be used as the static critical instability displacement Dcr-sta=0.74 of the lattice shell.

[0058] Further, in step S2, if the connected lattice shell structure does not have an overall instability failure mode in the target direction, it is determined that the dynamic stability of the connected lattice shell structure in the target direction meets the requirements. Figure 1 As shown in the figure, if the dynamic stability of the conjoined lattice shell structure in one of the target directions meets the requirements, the subsequent analysis steps in this target direction can be skipped.

[0059] Furthermore, in step S3, the maximum total internal force of the connected lattice shell structure can be represented by the total reaction force of the support at one end, which can be determined by the sum of all support reactions at one end of the connected lattice shell structure or the sum of all rod internal forces on a cross section of the connected lattice shell structure.

[0060] Further, in step S3, the number of selected seismic waves is greater than one, a plurality of displacement time history data are obtained, and the maximum total internal forces of a plurality of connected lattice shell structures and the maximum relative displacements of the supports at both ends of the connected lattice shell structures are simultaneously obtained, thereby obtaining a plurality of critical internal forces for dynamic instability of the lattice shells or a plurality of critical displacements for dynamic instability of the lattice shells; the ratio of the average value of the critical internal forces for dynamic instability of the lattice shells to the average value of the maximum total internal force is used as the basis for judgment, or the ratio of the average value of the critical displacements for dynamic instability of the lattice shells to the average value of the maximum relative displacements of the supports at both ends of the connected lattice shell structures is used as the basis for judgment. Specifically, in step S3, this embodiment selects 7 seismic waves, namely wave 1 to wave 7, according to the requirements of the seismic code, and performs elastic-plastic time-history analysis on the overall structure; the connected lattice shell structure of this embodiment has a total of 15 supports at the loading end, which are recorded as support 1 to support 15, and the seismic displacement responses of the corresponding positions of each support of the loading end structure monomer under the 7 seismic waves are extracted respectively, and are recorded as response 1-1, response 1-2...response 1-7, response 2-1, response 2-2...response 2-7...response 15-1, response 15-2...response 15-7, that is, the first digit of the seismic displacement response represents the number of the support, and the second digit represents the number of the seismic wave; the seismic displacement response is the displacement time-history data required to be used in the subsequent step S4, and the maximum total internal forces F1, F2...under the 7 seismic waves and the maximum relative displacements D1, D2...of the supports at both ends of the connected lattice shell structure can also be obtained simultaneously.

[0061] Corresponding to the above implementation, step S5 further includes the following steps:

[0062] S51: Take the average value of F1, F2, ..., F7 as the maximum total internal force F under the target level earthquake, and take the average value of D1, D2, ..., D7 as the maximum relative displacement D under the target level earthquake;

[0063] S52: Determine the dynamic stability of the connected lattice shell structure in the target direction and the safety margin under the target level earthquake based on the ratio of the critical internal force of dynamic instability of the lattice shell to the maximum total internal force, or determine the dynamic stability of the connected lattice shell structure in the target direction and the safety margin under the target level earthquake based on the ratio of the critical displacement of dynamic instability of the lattice shell to the maximum relative displacement.

[0064] Furthermore, in step S4, when performing dual nonlinear displacement loading dynamic time history analysis, the maximum displacement loaded at the loading end is gradually increased from a value lower than the static critical instability displacement of the lattice shell.

[0065] Furthermore, the kth level maximum displacement is a times the static critical instability displacement of the lattice shell, k=1, 2, 3..., a=k / 10.

[0066] Furthermore, the maximum total internal force of the connected lattice shell structure under the first level maximum displacement is F 1, the maximum total internal force of the connected lattice shell structure under the kth maximum displacement is F k , the maximum total internal force of the connected lattice shell structure under the k+1th maximum displacement is F k+1 , when F k+1 -F k <F 1 *5%, the kth maximum displacement is taken as the critical displacement of dynamic instability of the lattice shell, and the kth maximum total internal force is taken as the critical internal force of dynamic instability of the lattice shell.

[0067] Specifically, when the double nonlinear displacement time history loading is performed on the support displacement time history data under each seismic wave at the corresponding support position, the loading amplitude starts from 0.1Dcr-sta = 0.074m, and increases step by step with each 0.1Dcr-sta = 0.074m as an increment, that is, response 1-1 to response 15-1 are loaded to support 1 to support 15 respectively, and the displacement loading amplitudes are 0.074m, 0.148m, 0.222m, etc., respectively, so that the following can be obtained: Figure 5 The total internal force distribution curve of the connected lattice shell structure under different seismic waves is shown; if the deformation of the connected lattice shell structure is too large and the calculation cannot converge or the increment compared with the maximum total internal force under the previous displacement is less than 5% of the maximum total internal force under the first displacement, the loading can be stopped. At this time, the displacement amplitude of the previous loading can be defined as the critical displacement Dcr1 of the lattice shell dynamic instability of wave 1, and the total internal force of the previous level can be defined as the critical internal force Fcr1 of the lattice shell dynamic instability of wave 1. Waves 2 to 7 are also calculated in the same way, which are recorded as Dcr2 to Dcr7 and Fcr1 to Fcr7 respectively; the average value of Dcr1 to Dcr7 is taken as the final critical displacement Dcr of the lattice shell dynamic instability, and the average value of Fcr1 to Fcr7 is taken as the final critical internal force Fcr of the lattice shell dynamic instability. The calculation process of Dcr is shown in the following table:

[0068] seismic waves Critical displacement of dynamic instability of lattice shell (unit: m) Wave 1 0.59 Wave 2 0.59 Wave 3 1.04 Wave 4 0.67 Wave 5 0.67 Wave 6 0.81 Wave 7 0.52 DcR 0.70

[0069] The calculation process of Fcr is shown in the following table:

[0070] seismic waves Critical internal force of lattice shell instability (unit: kN) Wave 1 47708.0 Wave 2 47062.3 Wave 3 45915.7 Wave 4 47145.5 Wave 5 45464.7 Wave 6 54102.8 Wave 7 54417.5 F 48830.9

[0071] Furthermore, in step S51, a rare earthquake elastoplastic time-history analysis is performed on the overall structural model including the structural monomers on both sides and the connected lattice shell structure, and the maximum relative displacement at both ends of the connected lattice shell structure is obtained to be D=0.104m, and the maximum total internal force is F=4854kN; then K=Dcr / D or K=Fcr / F can characterize the safety factor of the connected lattice shell structure, and the larger the K value, the higher the safety margin; specifically, in this embodiment, the safety factor K=2.0 is set as the lower limit of the safety factor. By substituting the data into calculation, it can be seen that this embodiment satisfies Dcr / D≥2.0, Fcr / F≥2.0, so the dynamic stability of the connected lattice shell structure of this embodiment in the target direction meets the requirements; other target directions are analyzed in the same way.

[0072] Example 2

[0073] like Figure 2 As shown, based on Example 1, when performing dual nonlinear displacement loading dynamic time history analysis in step S4, the following method can be used to reduce the amount of calculation:

[0074] The maximum displacement loaded at the loading end is at least 1.5 times the static critical instability displacement of the lattice shell. Specifically, the bearing displacement time history data under each seismic wave is subjected to double nonlinear displacement time history loading at the corresponding bearing position. For example, response 1-1 to response 15-1 are loaded to bearings 1 to 15 respectively, and the same calculation is performed on waves 2 to 7, and the loading amplitude is 1.5Dcr-sta=1.11m; after obtaining the calculation results, the maximum total internal forces F1 to F7 of the entire process of the 7 seismic waves are extracted, and the average value of the maximum total internal forces F1 to F7 is taken as the critical internal force Fcr of the dynamic instability of the lattice shell. The calculation process is shown in the following table:

[0075] seismic waves Maximum total internal force (in kN) Wave 1 47708.0 Wave 2 47062.3 Wave 3 45915.7 Wave 4 47145.5 Wave 5 45464.7 Wave 6 54102.8 Wave 7 54417.5 F 48830.9

[0076] In step S51, this embodiment performs a rare earthquake elastoplastic time-history analysis on the overall structural model including the two-side structural monomer and the conjoined lattice shell structure, and extracts the maximum total internal force F=4854kN of the conjoined lattice shell structure, then K=Fcr / F can characterize the safety factor of the conjoined lattice shell structure, and the larger the K value, the higher the safety margin; specifically, this embodiment sets the safety factor K=2.0 as the lower limit of the safety factor, and it can be seen from the data calculation that this embodiment satisfies Fcr / F≥2.0, so the dynamic stability of the conjoined lattice shell structure in the target direction of this embodiment meets the requirements; if Fcr / F<2.0, it is necessary to adjust the layout of the conjoined lattice shell structure or the cross-sectional shape of the rods. Other target directions are analyzed in the same way.

[0077] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for dynamic stability analysis of a conjoined lattice shell structure under earthquake action, characterized in that: The following steps are included: An analysis model of a conjoined lattice shell structure is established, with at least one end of the analysis model being a loading end; a displacement action is applied in a target direction of the loading end, and single nonlinear static analysis and double nonlinear static analysis are performed on the analysis model, and it is determined whether the conjoined lattice shell structure has an overall instability failure mode in the target direction according to the analysis results; When the connected lattice shell structure has an overall instability failure mode in the target direction, the target intensity seismic wave is selected to perform elastic time history analysis or elastoplastic time history analysis on the overall structure to obtain the displacement time history data of the loading end and the maximum total internal force of the connected lattice shell structure or the maximum relative displacement of the two end supports under the target intensity earthquake; the displacement time history data is used to perform a double nonlinear displacement loading dynamic time history analysis on the loading end until the connected lattice shell structure is unstable and destroyed, and the critical internal force of dynamic instability of the lattice shell structure or the critical displacement of dynamic instability of the lattice shell structure is obtained; the dynamic stability of the connected lattice shell structure in the target direction is judged based on the critical internal force of dynamic instability of the lattice shell or the critical displacement of dynamic instability of the lattice shell.

2. The method for dynamic stability analysis of a conjoined lattice shell structure under earthquake action according to claim 1, characterized in that: It also includes the following steps: Conduct elastic time history analysis or elastoplastic time history analysis on the analysis model under target level earthquake to obtain the maximum total internal force or maximum relative displacement of the connected lattice shell structure; The dynamic stability of the connected lattice shell structure in the target direction and the safety margin under the target level earthquake are determined based on the ratio of the critical internal force of the lattice shell dynamic instability to the maximum total internal force, or the dynamic stability of the connected lattice shell structure in the target direction and the safety margin under the target level earthquake are determined based on the ratio of the critical displacement of the lattice shell dynamic instability to the maximum relative displacement.

3. The method for dynamic stability analysis of a conjoined lattice shell structure under earthquake action according to claim 1 is characterized in that: When the load-displacement curve of the dual nonlinear static analysis has an extreme point and the load-displacement curve of the dual nonlinear static analysis is lower than the load-displacement curve of the single nonlinear static analysis as a whole, it is judged that the connected lattice shell structure has an overall unstable failure mode in the target direction.

4. A method for analyzing the dynamic stability of a conjoined lattice shell structure under earthquake action according to any one of claims 1 to 3, characterized in that: When performing dual nonlinear displacement loading dynamic time history analysis, the maximum displacement loaded at the loading end increases step by step from a value lower than the static critical instability displacement of the lattice shell.

5. The method for dynamic stability analysis of a conjoined lattice shell structure under earthquake action according to claim 5 is characterized in that: The kth level maximum displacement is a times the static critical instability displacement of the lattice shell, k = 1, 2, 3..., a = k / 10.

6. The method for dynamic stability analysis of a conjoined lattice shell structure under earthquake action according to claim 6 is characterized in that: The maximum total internal force of the connected lattice shell structure under the first level of maximum displacement is F1, and the maximum total internal force of the connected lattice shell structure under the kth level of maximum displacement is F k , the maximum total internal force of the connected lattice shell structure under the k+1th maximum displacement is F k+1 , when F k+1 -F k <F1*5%, the kth maximum displacement is taken as the critical displacement of dynamic instability of the lattice shell, and the kth maximum total internal force is taken as the critical internal force of dynamic instability of the lattice shell.

7. A method for analyzing the dynamic stability of a conjoined lattice shell structure under earthquake action according to any one of claims 1 to 3, characterized in that: When performing dual nonlinear displacement loading dynamic time history analysis, the maximum displacement loaded at the loading end is greater than or equal to 1.5 times the static critical instability displacement of the lattice shell.

8. A method for analyzing the dynamic stability of a conjoined lattice shell structure under earthquake action according to any one of claims 1 to 3, characterized in that: The number of selected seismic waves is greater than one, and a plurality of displacement time history data, a plurality of maximum total internal forces of connected lattice shell structures and a plurality of maximum relative displacements of supports at both ends of the connected lattice shell structures are obtained, thereby obtaining a plurality of critical internal forces for dynamic instability of the lattice shells or a plurality of critical displacements for dynamic instability of the lattice shells; the ratio of an average value of the critical internal forces for dynamic instability of the lattice shells to an average value of the maximum total internal forces is used as a basis for judgment, or the ratio of an average value of the critical displacements for dynamic instability of the lattice shells to an average value of the maximum relative displacements of supports at both ends of the connected lattice shell structures is used as a basis for judgment.

9. A method for analyzing the dynamic stability of a conjoined lattice shell structure under earthquake action according to any one of claims 1 to 3, characterized in that: When static analysis applies displacement, the ground displacement is zero, the displacement of the support with the highest elevation at the loading end is one, and the displacements of each support at the loading end are distributed in a linear difference along the height direction.

10. A method for analyzing the dynamic stability of a conjoined lattice shell structure under earthquake action according to any one of claims 1 to 3, characterized in that: When there is no overall instability failure mode of the connected lattice shell structure in the target direction, it is judged that the dynamic stability of the connected lattice shell structure in the target direction meets the requirements.

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