轻质组装墙板内置钢板支撑滞回性能试验研究

为改善墙板内置钢板支撑的延性，避免钢筋混凝土墙板局部冲切破坏，便于检修内置支撑和减小墙板自重，提出了轻质组装墙板。通过对6个组装墙板内置钢板支撑的试验研究，考察了支撑和墙板的厚度、支撑与墙板间的间隙等构造对支撑滞回性能的影响。试验表明，轻质组装墙板内置Q235钢板支撑具有良好的延性和耗能能力。总体上，墙板内置支撑破坏前骨架曲线呈双折线，支撑屈服后因钢材应变硬化以及支撑和墙板间摩擦等因素，支撑的承载力随侧移的增加而增大。达最大侧移角约1/25时，受拉承载力调整系数范围为1.36～1.61。侧移角在1/25以内时，受压承载力调整系数均小于13，支撑的轴向累积非弹性变形能力远大于200，均满足美国ANSI/AISC 341 16的要求。试件最终因内置支撑受拉断裂而破坏，破坏前滞回曲线饱满稳定。组装墙板保持完好，可重复利用。支撑与墙板间留置适宜间隙后，受压支撑在墙板孔壁内仅发生微幅多波弯曲变形，避免了墙板局部破坏。当仅考虑支撑附件的主钢管和开孔钢板简化计算墙板绕钢板支撑弱轴的欧拉临界力，墙板的欧拉临界力与内置支撑的最大轴向受压承载力之比(约束比)达1.15~2.42，墙板内置支撑不发生受压整体失稳。

Tests on hysteretic behavior of steel plate brace encased in light weight assembled panel

Light weight assembled steel panel was proposed to improve the ductility of steel plate brace encased in panel, to avoid local punching failure of reinforced concrete panel, to inspect encased brace and to reduce the weight of the panel. Six tests on steel plate brace encased in assembled panel, which is referred to as panel buckling restrained brace (panel BRB), have been carried out to investigate the effects of constructional details, including thickness of both encased brace and panel, gaps between panel and brace, on the hysteretic behavior of the panel BRBs. The tests revealed that the light weight panel BRBs, with Q235 steel plate brace, have good ductility and energy dissipation capacity. In general, the panel BRBs before final failure show bilinear skeleton curves, and the load carrying capacities of the panel BRBs increase with increasing lateral displacement due to the effects of strain hardening and the friction between the panel and brace after yielding. The compression strength adjustment factor at the maximum drift of 1/25 is from 1.36 to 1.61. The compression strength adjustment factors within the drift of 1/25 are all less than 1.3 and the cumulative inelastic axial deformation capacity of each panel BRB is significantly larger than 200, satisfying the requirements of ANSI/AISC 341 16. The hysteretic curves of each panel BRB are stable prior to tension fracture. The assembled panels remained intact and therefore can be reused. The encased brace only developed small multiple wave flexural deformations due to appropriate gaps kept between the panel and the encased brace and hence local failure of panel was avoided. The main tubes and steel plates with bolt holes around encased brace were considered only to simplify the calculation of the Euler buckling strength of panel. The overall buckling of the panel BRBs was prevented when the restraining ratios between the Euler buckling strength of panel about the weak-axis of the plate brace, and the maximum axial strength of encased brace are within 1.15 to 2.42.