Stability and Dynamic Analysis of Cold-formed Storage Rack Structures With Semirigid Connections

This paper presents the finite element buckling and dynamic analyses of two-dimensional (2D) single frames and three-dimensional (3D) frames of cold-formed sections with semirigid connections used in the conventional pallet racking system. The results of buckling analysis for the single 2D frames are compared with those from the experimental study and effective length approach given by RMI. The finite element model used for the single 2D plane frame is further extended to 3D frames with semirigid connections, for which the buckling analysis results are obtained. The buckling and dynamic analyses are carried out using ANSYS for 18 types of developed column sections. The stiffness of the semirigid connection is determined by both the single and double cantilever test methods, along with the nonlinear finite element analysis. Further, an equivalent single degree-of-freedom model is proposed for simulating the seismic behavior of the storage rack in the down-aisle direction, aimed at developing simplified equations for the fundamental period, base shear, and top displacement of the rack. A parametric study is carried out to compute the fundamental period and mode shape. The transient dynamic analysis is also performed for evaluating the impact of the forklift on columns of the frame.