Collapse Simulation Of Space Steel Frame Structure Under Earthquake Action Based On The Finite Particle Method

The collapse of space steel frame structure under earthquake action frequently involves some complex issues,including dynamic behavior,geometric nonlinearity,material nonlinearity,fracture,contact and collide,etc.However,due to the theoretical constraints,it is difficult for traditional finite element method to solve such complex problems.Based on the finite particle method and the existing research results,regarding simulation of collapse as the main line,using the MATLAB program for calculation,this paper simulates and analyzes the collapse process of space steel frame structure under earthquake action,as an addition,the failure mechanism of the collapse process is studied.The main research work is as follows:First of all,this work systematically expounds the fundamentals of the Finite Particle Method and derives the formulations of space beam structure in detail.Then,the influence of particle density on calculation accuracy is discussed and the stability of the algorithm is verified by several numerical examples,indicating that the increase of particle density is helpful to improve the calculation accuracy.Based on the previous study,the basic program framework for the use of space beam elements for dynamic and static analysis is organized through the MATLAB software.Secondly,a space steel frame model based on the Finite Particle Method is established and the method of calculating time step and mass damping is proposed,based on which the static analysis and dynamic response analysis under seismic action are implemented.It can be found that the results are almost identical compared with the finite element analysis results.Therefore,the validity of the analysis model based on the Finite Particle Method and the validity of the seismic response analysis are verified in this work.Finally,according to the characteristics of the Finite Particle Method,the basic framework of the Finite Particle Method for dealing with structural geometric nonlinearity and material nonlinearity is proposed,and the method of calculating the fracture criterion,the failure mode and the calculation of the mass property of the member after the fracture of the member are established.In this process,several numerical examples are presented to demonstrate the accuracy and capability of the nonlinear analysis and the fracture algorithm which are developed in this work.Last and most important,the collapse process of the space steel frame under earthquake is simulated,and the morphological changes together with internal force changes in the process of structural collapse are traced,providing more profound understanding of structural damage mechanism.Theoretical derivation,numerical simulation and programming of the program demonstrate that the Finite Particle Method is feasible and effective for the simulation of structural collapse under earthquake action.Meanwhile,it also provides a new effective analysis tool for the collapse of the structure under earthquake action.