Collapse Mechanism And Design Criterion Of Steel Staggered Truss System Under Cyclic Load

Staggered truss structure system developed in last 60's in American has been widely studied and used in abroad because it can yield great economy and maximum architectural and planning flexibility.The researches of this structural system have been lasting since it was introduced to China in last 80's.There still did not have a design code for the structure system because of lack of research,meanwhile,the application of the structure system still in exploring.Cognition on the failure mechanism of this system was rather inadequate because studies on staggered truss system were very limited.To accelerate the use of this system in China,The analysis of failure mechanism and design criterion of staggered truss system under seismic load is significant for theory and practice.In order to study the hysteretic behavior of staggered truss system and verify the validity of theoretical method,a composite staggered truss structural system model and a vierendeel structural system model staggered truss were tested under cyclic load.Result of the experiment revealed that the system had excellent hysteretic behaviors,and the determination factor,which has crucial influence on the behavior,is the type of truss.On the fundamental research aspect of the structure system,the study on the behaviors under monotonic load was focused before in China and in abroad.This paper firstly carried out nonlinear finite element methods analysis on the seismic behaviors of the steel staggered truss structure system under cyclic loading,and more than 30 species of 7 series are analyzed after verification of FEM.The major factors include dimensions of truss span,dimensions of camber of truss,dimensions of the middle panel of truss,number of the truss panel,and so on. Suggestions for seismic design based on test and FEM analysis are presented at last.The analysis of steel staggered truss structure system seismic behaviors is of great importance in structural filed,and the foreground of study and application is very wide.The conclusion of this paper can be useful for establishing design code,guiding design of engineering,and provide good basis for further study on seismic-resistant behavior of steel staggered truss system.