Hot Spot Stress Concentration Factors of Diamond Bird-Beak SHS T-Joints

Diamond bird-beak joint is a new type of welded joint in truss structures made of square hollow section(SHS) members.In need of fatigue behaviour,the hot spot stress concentration factors(SCF) of the type of T-joint under axial force and in-plane bending on the brace respectively were analyzed using finite element method,and the effects of nondimensional geometric parameters β,2γ and τ on the SCFs were investigated.The feature of SCFs of the bird-beak SHS joints was compared with that of the normal SHS joints.It is concluded that for the bird-beak SHS joints the hot spot stresses both in the brace and in the chord are located at the saddle for the brace subjected to axial force,whereas they are located at the crown for the brace subjected to in-plane bending.The bird-beak SHS joints have much lower SCFs than the normal SHS joints,which indicates that the former joints have better fatigue behaviour than the latter joints.