Influence of sheet/purlin fasteners spacing on shear flexibility of the diaphragm

The paper presents the influence of sheet/purlin fasteners location (in reference to trapezoidal profile cross section) on shear flexibility of the cladding acting as a diaphragm. Analytical procedures were presented and their limitations were discussed. Next, selected schemes of fasteners location, known from engineering practice, but not included in European codes and recommendations, were analysed numerically in order to observe the differences in shear stiffness of the panel. The cantilevered diaphragm as a part of the roof of a single storey building was chosen for the analysis. The analysis was carried out for the valley-fixed trapezoidal sheeting with wide pans. Corrugated sheets were built by two types of models: full 3D shell model and equivalent orthotropic 2D shell model. Flexibility of fasteners and connections was included in the calculations using equivalent beam finite elements. The results were discussed from the stressed-skin design point of view