无粘结内藏钢板支撑剪力墙滞回性能分析

结合单斜无粘结内藏钢板支撑剪力墙的试验研究,对其滞回性能进行了有限元分析.考察了钢板支撑不同初始缺陷和墙板端部有无加强构造等因素对支撑墙板受力性能的影响.试验和分析结果均表明,墙板端部有角钢加强的试件,钢板支撑受压屈服后,在水平侧移角达1/50时墙板没有破坏,支撑墙板滞回曲线饱满稳定;端部没有加强的试件,在支撑受压屈服后,墙板端部局部开裂严重.分析还表明,内藏的钢板支撑在受压后只发生多波微幅弯曲失稳.随着沿墙板厚度方向墙板孔壁与支撑间间隙的增大,支撑的失稳波幅也增大,从而降低支撑墙板的初始刚度和受压承载力,增大支撑对墙板的局部冲剪力和墙板平面外的弯曲变形.当墙板的侧向约束足够时,墙板支撑受压和受拉时的性能较一致且无承载力和刚度退化,可以在结构分析中应用杆元对其进行模拟.

Numerical analysis on hysteretic behavior of unbonded steel plate brace encased in reinforced concrete panel

In comparison with the test results,the finite element analysis on the hysteretic behaviors of the single-diagonal unbonded steel plate brace encased in reinforced concrete panel,which is referred to as panel buckling restrained brace(panel BRB) hereafter,has been carried out.The effects of some constructional factors,including initial geometric imperfection of the steel brace and the reinforcements at the ends of panel,on the working behaviors of panel BRB were examined in this analysis.The results of analysis and test indicate that the panel BRB with angle reinforcement doesn’t fail before 1/50 lateral drift and has stable hysteretic behaviors and plump hysteretic loops.In contrast,cracks in the panel BRB without this reinforcement occur severely at the ends of panel after yielding of the steel brace.Analysis results also reveal that the core brace under compression only appears very small flexural buckle with multiple waves.With the increase of clearance between core brace and hole of the panel across thickness of panel,amplitude of the buckling wave of the brace and punching force of the brace to the panel,as well as out-of-plane flexural deformation of the panel,will increase,resulting in the decrease of the elastic stiffness and the ultimate capacity of panel BRB.When the lateral restraint of the panel is sufficient,working behaviors of the panel BRB in compression can be compared with those in tension,and the deterioration of strength and stiffness can be avoided,which makes it convenient to simulate panel BRB by a truss element in structural analysis.