Mechanical properties of corrugated steel lap joint under combined compression and bending

The lap joint of a prefabricated corrugated steel structure is one of the most critical components to be considered during design. Full-scale mechanical tests under combined compression and bending (N-M) were conducted to investigate the effect of axial forces and bending moments on the mechanical behavior of lap joints. Numerical methods were used to examine the effects of different axial forces on the bending behavior of the joint. Analysis revealed that buckling of the corrugated steel plate lapped on the upper layer, located near the innermost row of bolt holes, was the failure mode of the lap joint. The yield of the bolt holes on the compression (crest) and tension (valley) sides was accelerated and postponed by the axial force, respectively. Additionally, three phases with linear, nonlinear, and linear characteristics were identified from the bending moment-rotational angle (M-theta) curves. The initial rotational stiffness of the joint was the highest and decreased gradually with increasing axial force. The residual rotational stiffness of the joint was minimal and was only minimally affected by the axial force. A greater axial force on the joint lowered the bending capacity. Compared with N = 0, when N = 1200 kN, the corresponding bending moment decreased by approximately 17.1% and 9.6% for theta = 0.02 and 0.1, respectively. An empirical formula for calculating the joint rotational stiffness (K theta) was proposed based on the N-M-K theta relationship. These findings provide a reference for the joint design of prefabricated corrugated steel structures.