A New Yield Line Theory Based Design Approach for Ultimate Capacity of Welded RHS X-joints

摘要

The load capacity equations for structural hollow section joints given in design guidance documents are frequently based on the yield line theory. These predictions are then confirmed or adjusted based on experimental findings. The calculated capacities are valid only for a certain failure pattern. For welded rectangular hollow sections (RHS) X- and T-joints, the failure can take place in the brace member, in the chord member or partly in both members. In this study the last mechanism is taken as general failure mode which covers other mechanisms. Theoretical load carrying capacity for this new mechanism is presented and it is compared with some experimental test results. The derived mechanism is applied to define optimal joint geometries for X- and T-joints.