Design Assisted by Finite Element of Z‐Purlins with Overlapping under Gravity Loading

Abstract

Cold‐formed steel Z‐purlins are generally designed to span continuously over rafters. The bending moment continuity or semi‐continuity is obtained by overlapping the profiles or using a sleeved connection. Lapped connections are regarded as superior in terms of stiffness and resistance compared to their sleeved counterpart. A finite element model was developed and validated against experimental results to be used in a parametric study. The study investigated the influence of parameters such as: cross‐section dimensions, span length, symmetrical and unsymmetrical overlap lengths, connection detailing, trapezoidal sheeting thickness and connection. The numerical results show that the mechanical behavior of overlapped purlins loaded by gravity is mainly influenced by the span and the length of overlapping. The connection detailing is particularly important for short overlaps.