Nonlinear buckling and failure analysis of a self-weighted metallic roof with and without skylights by FEM

In this research work, a nonlinear structural analysis by the finite element method (FEM) is carried out to study the structural collapse of a self-weighted metallic roof with and without skylights located in Cabañaquinta’s schoolyard (Principality of Asturias, Northern Spain). The collapse of this cable-arch structure was due to huge snow loads in winters of 2004 and 2006. In order to tackle this structural problem, it is proposed a damage assessment based on the nonlinear post-buckling analysis of the entire self-weighted metallic roof by FEM. Firstly, in order to obtain a diagnosis of the failure causes, several FEM models with six tiles of a 0.83 m wide and 1.25 mm thickness, including methacrylate skylights in one of them, were built and then solved as a three steps procedure: a linear pre-stress analysis, a buckling analysis and a nonlinear analysis. Secondly, a procedure based on the design of experiments (DOEs) applying the FEM technique was used to determine the importance of different parameters on the structural integrity of the roof. Finally, the numerical results of this work are discussed and the structural design recommendations are explained in detail to avoid these structural failures in the future.