New reduction factor for cracked multi-planar square hollow section TT-, YT- and KT-joints

Many existing multi-planar structures such as bridges, buildings and others are fabricated using square hollow section (SHS) members. There are no guidance's available in the design codes to assess the safety and integrity of these cracked multi-planar SHS joints till date. This paper proposes a new set of equations for determining the reduction factor (FAR) of cracked multi-planar SHS TT-, YT- and KT-joints. A completely new and robust finite element (FE) mesh generator is developed and it is validated using the experimental test results. Parametric study is carried out for multi-planar SHS joints subjected to axial loading at the brace end. The results reveal that the crack area and the brace to chord width ratio (β) have an important effect on the plastic collapse load of the cracked SHS joints. For a particular β value, the FAR varies up to 4.37% for different values of crack area.