Bearing Length on Cold-Formed Sections

摘要

The effective bearing length of trapezoidal sheeting on cold formed sections at inner supports is 10 mm according to EN 1999-1-4 (aluminium) and EN 1993-1-3 (steel). In the original design provisions the effective bearing length on Z-sections was the actual width of the loaded flange. In order to find out the appropriate effective bearing length, FEM calculations were made on simply supported beams with C-, Z- and Sigma- cross-section. Contact elements between the trough of the trapezoidal sheeting and the loaded flange of the beam made it possible to evaluate the contact area. This area and the stresses in the trapezoidal sheeting show that the effective bearing length is very small for C-sections. For Z- sections and for Sigma sections with large folds in the web the contact area is the flange width, unless the flange width versus profile height is large and the plate thickness is small.