ABSTRACT
This study is part of an extensive research conducted to assess the structural behaviour of standing seam metal roof under up-lift wind pressure. A three-dimensional finite element model, based on a degenerated shell element, is developed for a full-scale roof that was previously tested under uniform and variable up-lift pressure at Mississippi State University (MSU), USA. In this model, the seams and the clips were simulated using equivalent spring systems. In a previous study, the properties of the spring simulating the clips were evaluated experimentally for an undeformed configuration of the seams. In the current study, this experimental program was extended by testing the clips while the seams are maintained at a certain state of constant deformation. The tests were repeated for various values of seam deformations. A significant reduction in the clip stiffness was observed with the increase in the seam deformation. A relationship between the clip stiffness and the seam deformation was established from the test results. This non-linear relation is to be incorporated into the finite element model in order to capture the failure mechanism of standing seam roof.
