Study of influences of varying perforated infill-plate configurations on the cyclic performance and energy absorption of LYP-SPSW system

Previous studies were investigated the use of perforated plates or low yield point (LYP) steel individually, but the combined influence of LYP steel infill plates with diverse perforation layouts remains insufficiently investigated. Addressing this gap, the present study was examined varying circular perforation configurations including central, corner, mid-side, and uniformly distributed openings affect the cyclic behaviour and failure mechanisms of LYP-SPSW systems. The innovation of this research lies in its systematic evaluation of both perforation geometry and perforation ratios (10-50%) within LYP160 steel infill plates designed according to AISC 341 provisions. Finite element (FE) models were developed using ANSYS and validated against benchmark experimental studies. The parametric analyses were conducted to quantify the perforation effects on elastic stiffness, yield and ultimate strength, hysteretic behaviour, energy dissipation, stress distribution, and equivalent plastic strain. Results indicated that perforation layout, rather than perforation size alone, dominates seismic performance trends. Uniformly distributed (U) and mid-side (MS) configurations most effectively preserve the diagonal tension-field mechanism, achieving 85-95% of the stiffness and strength of solid infill walls, while maintaining high energy dissipation and stable hysteresis. In contrast, central openings significantly disrupt stress trajectories, induce localised strain concentrations, and lead to pronounced reductions in strength, stiffness, and ductility particularly beyond a 30% opening ratio. Stress and plastic strain analyses confirm the superior damage distribution of U and MS patterns, while CE layouts exhibit premature localised failure.