Nonlinear Structural Response Assessment of Steel–Concrete Composite Beams Under Repeated Cyclic Loading Conditions

Abstract

Steel–concrete composite beams are extensively used in modern structural engineering applications due to their high load-carrying capacity, improved stiffness, and efficient material utilization. However, repeated cyclic loading caused by seismic activity, traffic movement, wind forces, and industrial vibrations can significantly influence the nonlinear structural behavior and long-term durability of composite beam systems. This research presents a nonlinear structural response assessment of steel–concrete composite beams under repeated cyclic loading conditions to evaluate deformation characteristics, stress redistribution, energy dissipation, and failure mechanisms. The proposed study employs nonlinear finite element analysis and experimental validation techniques to investigate the structural response of composite beams subjected to varying cyclic load amplitudes and loading frequencies. The numerical model incorporates material nonlinearity, interface interaction behavior, stiffness degradation, and crack propagation mechanisms to simulate realistic structural performance under repeated loading conditions. Different beam configurations, reinforcement arrangements, and shear connector designs are analyzed to determine their influence on structural stability and fatigue resistance. Performance evaluation is conducted using parameters such as load-deflection response, hysteretic behavior, residual deformation, stress concentration, energy absorption capacity, and ductility performance. Comparative analysis is further performed to assess the effectiveness of various composite beam designs in improving cyclic load resistance and minimizing structural degradation. Simulation and experimental results demonstrate that repeated cyclic loading significantly affects the nonlinear response and fatigue performance of steel–concrete composite beams.