Finite element based simulation of diaphragm action on light weight composite plywood to sheet metal roof element

Abstract Two Finite Element (FE) models are built to simulate diaphragm action on light weight roof elements made of plywood, metal sheeting and solid wood rows. One model is simple and one is complex. The scope of this study is to verify the FE-models by full scale tests previously done. To compare the model and the tests both global and local deformations on the elements will be considered. The models will form a foundation for further development of FE- analysis based calculations for practical and scientific proposes on Lett-Tak AS. The FE-models built has not fully been verified by the tests, but the model simulates and quantifies important effects observed in the test. Among these effects are increasing of shear capacity of the plywood diaphragm because large forces are transmitted to the edge-beams. And uplift forces because of eccentricity between the plywood panels and the support joint on the edge beam. It has been shown that the configuration used to model the fasteners in the gable support overestimates the stiffness and ultimate load of the fastener. The FE-model developed in this study, a foundation for further research on the stress and strain interactions between the material components and joints