Tensile performance and multi-objective optimization of novel kinked connected components (KCCs)

Abstract

This paper proposes a novel kinked connected component (KCC) with a uniquely wave part that offers substantial deformation capacity and reserve. The KCC significantly strengthens connection joints, thereby improving resistance to progressive collapse. To validate the superior ductility in KCC, tensile performance tests and finite element simulations are conducted, comparing its resistance mechanisms and failure modes with those of straight connected plate (SP). Additionally, the influence of two key parameters is analyzed, i.e., wave height (h_KCC) and wave length (l_KCC), under different thicknesses of KCC (t_KCC), followed by a comprehensive multi-objective optimization. The findings reveal that the KCC progresses through four stages under loading: an elastic stage, a straightening stage, a strengthening stage, and a necking stage. Compared to SP, the KCC demonstrates lower initial stiffness yet exhibits similar failure modes and ultimate strengths. Remarkably, the KCC improves the deformation capacity (displacement at ultimate load) by 30–100 % relative to SP. However, excessive h_KCC coupled with insufficient l_KCC may lead to premature failure at the wave part, significantly reducing both strength and deformation performance. The multi-objective optimization analysis identifies optimal combinations of h_KCC and l_KCC, achieving enhanced performance metrics, including maximum force (F_max) and its corresponding displacement (u_Fmax). The KCC-implemented prefabricated beam-column joints demonstrate dual mechanical enhancement due to the special waveform design, achieving amplified catenary action that enhance progressive collapse resistance. These innovative aspects have made significant contributions to the design of corrugated connections, opening new possibilities for enhancing the progressive collapse performance of structures.