Engineering reports

Recommendations Executive Summary This report evaluates the assumption that joints which display semirigid behaviour can be modelled as frictionless pinned joints in building design calculations. The idealisation is evaluated by comparing computer simulations incorporating this assumption with experimental test data for the actual structure. The results show that the idealisation is safe and is usually conservative in estimating the structural strength; however these conclusions are limited to cases where the joints display large deformations before rupture of the bolts or welds. Only in few, probably unrealistic cases will this assumption lead to unsafe results which overestimate strength. It is recommended that three conditions are necessary for the safety of semi-rigid joints: joints must show enough ductility, welds must be well designed in order to avoid premature fracture and the design of the joint must be such that the rotation is practically possible.