装配式可退化支撑受力性能分析及试验研究

Mechanical behavior and experimental study on prefabricated brace with degenerated bearing capacity

装配式可退化支撑主要由外筒、内筒、核心板及约束部件组成,通过对其承载力退化及受力性能进行分析,提出描述可退化支撑恢复力特性的力学模型。通过3组装配式可退化支撑的低周往复加载试验对其构造的可行性进行验证,研究不同核心板厚度对滞回特性、承载力退化及耗能能力的影响,并与提出的力学模型的分析结果进行对比。结果表明:无论在压力或拉力作用下,可退化支撑均可通过核心板的局部受压屈曲实现支撑整体承载力的退化;支撑受拉、受压承载力具有较好的对称性,刚度与耗能能力呈现不对称的特点;相同初始挠度下,可退化支撑的相对承载力随核心板厚度增加而提高;可退化支撑通过核心板屈曲耗能,耗能能力随核心板厚度的增加而提高;三折线恢复力模型能够有效地反映支撑构件的实际受力情况。

A prefabricated brace with degenerated bearing capacity is composed of outer tube,inner tube,core plate and restrained component. The degradations of the bearing capacity and mechanical behaviors of the brace were analyzed,and a mechanical model describing the restoring force characteristics of the brace was proposed. By conducting quasi-static reversed cyclic tests on three prefabricated brace specimens with degenerated bearing capacity,the effects of the thickness of core plate on the hysteretic behavior,degradation of bearing capacity and energy dissipation capacity were studied,and the test results were compared with the mechanical model. The test results show that the brace can achieve the degradation of overall bearing capacity through local compression buckling of the core plate under either the compression or tension load. The tensile and compressive bearing capacities of the braces are symmetric,whereas the stiffness and energy dissipation are not symmetric. With the same initial deflection,the relative carrying capacity of the braces increases as the thickness of the core plate increases. The energy dissipation of the braces is caused by the buckling of the core plate,and the energy dissipation capacity increases with the thickness of the core plate. The trilinear restoring force model can effectively reflect the loading carrying mechanism of the brace.