钢-混凝土连续组合梁的恢复力模型

Research of restoring force model on steel-concrete composite continuous beams

通过8根钢-混凝土连续组合梁在低周反复荷载作用下的试验,研究其恢复力特性。结果表明,荷载-跨中挠度滞回曲线随着位移的增大由梭形逐步过渡到近似的四边形;增大剪力连接度η和纵向综合力比Rp(中支座负弯矩区)连续组合梁仍然有很好的延性;组合梁的加、卸载刚度退化规律呈指数函数变化。根据研究结果提出能考虑剪力连接度和纵向综合力比影响的钢-混凝土连续组合梁的骨架曲线公式及恢复力滞回规则,建立荷载-跨中挠度(P-Δ)恢复力模型。

Based on the test results of seismic resistant performance of eight steel-concrete composite continuous beams under low-cycle reversed concentrated loads, the shape of hysteresis loop of the load-displacement （P-△） is obtained, which gradually changes from shuttle to quadrangle according as the increasing of displacement. Those beams with bigger degree of shear connection and longitudinal force ratio in the negative moment zone of interior support still have good ductility. The regularity of rigidity degeneration of either loading or unloading condition accords with exponential law. Based on the experimental research, proposed formulas for calculating the skeleton curve and hysteretic rule of load-displacement, restoring force model of steel-concrete composite continuous beams arc established in consideration of the degree of shear connection and lognitudinal force ratio.