波折钢板剪力墙内嵌墙板与框架的相互作用分析

Analysis of Interaction Between Infill Plate and Frame in Steel Corrugated Shear Walls

随着高层建筑的不断发展,水平荷载愈发成为结构设计中不可忽略的因素,钢板剪力墙因其优越的抗侧力性能,在实际工程中得到广泛的应用,研究人员对其受力性能开展了深入的研究。普通平钢板剪力墙具有较高的极限承载力,但在往复荷载作用下滞回曲线出现"捏拢",尤其是薄钢板会发出巨大噪声,影响结构舒适性。波折钢板由于波折的存在,具有更高的面外刚度,呈现出面内剪切屈曲的受力特征,延性较好。与普通平钢板剪力墙相比,其抗侧性能及墙板抗侧机制仍有待研究,且在水平荷载和竖向荷载共同作用下的受力性能研究也比较缺乏。通过有限元方法分析了内嵌波折钢板的抗侧力机制,提出相对应的框架柱门槛抗弯刚度要求,研究了竖向荷载对墙板性能的影响,给出工程实用设计建议。首先,利用有限元软件ABAQUS模拟循环加载试验,将试验与有限元拟合结果进行对比,验证利用ABAQUS软件分析波折钢板墙的有效性与准确性;通过对两个典型算例的荷载-位移曲线分析,指出波折钢板墙的两种不同的抗侧力机制,分析这两个算例的框架弯矩分布,表明波折钢板通过"四边受剪"或"拉力带"两种机制抵抗侧向力,且抗侧力机制由内嵌钢板的几何参数决定。如果波折板主要通过"拉力带"抵抗侧向荷载,由于波折的存在,"拉力带"不能充分发展,就会出现残余承载力较低的情况;其次,以非加劲平钢板剪力墙边缘柱的截面抗弯刚度要求为基础,分析框架在弹性和弹塑性两种情况下,边缘柱截面抗弯刚度对墙板性能的影响,指出正则化高厚比越大,柱截面抗弯刚度对墙板性能的影响越大,当正则化高厚比λ_n≤0.45时可以认为波折钢板主要通过"四边受剪"机制抵抗侧向力,这时对框架柱的抗弯刚度要求较小,可以采用截面抗弯刚度EI≥0.5EI~*的框架柱,在实际工程中推荐使用λ_n≤0.45的波折钢板以保证足够的残余承载力;最后,针对正则化高厚比小于0.45的波折钢板墙,研究竖向荷载对墙板性能的影响,改变作用在柱子上的轴向压力,观察墙板承载力的变化情况,指出竖向荷载对墙板极限承载力影响很小,但由于边缘柱在残余状态下产生较大的竖向压缩,导致墙板剪力不能有效传递,进而引起柱子残余承载力下降,正则化高厚比越大的墙板,残余承载力下降越严重,实际工程中可以通过增大柱截面面积避免这种情况的出现。

With the development of high-rise buildings,horizontal load has become a key factor in structural design. Steel plate shear walls( SPSWs) are widely utilized in practical engineering due to its superior lateral resistant performance. Researchers have carried out indepth research on the mechanical performance. SPSWs have advantages of high ultimate lateral resistance,but their disadvantages still exist: the hysteretic curve appears"pinching"under cyclic load,especially the huge noise produced by thin steel plate,which affect the human comfort of buildings. Corrugated steel plate has advantages of large out-plane stiffness and high ductility due to the existence of corrugation,"in-pate shear yielding"mechanism can be achieved. Compared with ordinary SPSWs,steel corrugated shear walls( SCSWs) still need further investigations. Analysis of lateral resistance of SCSWs under the combined action of lateral load and vertical load is lacking.The finite element analysis( FEA) was used to analyze the lateral resistant mechanism of SCSWs,and the corresponding threshold flexural rigidity of columns was proposed,influence of vertical load on the performance of infill plates was studied,and design suggestions were given. Firstly,the finite element software ABAQUS was used to simulate the cyclic load test,and the results of test and simulation fitted well,which verified the validity and accuracy of FEA. Through the load-displacement curves of two typical cases,two different lateral resistant mechanisms were revealed. The fact that corrugated plate could resist lateral load through"in-plate shear yielding"or"diagonal tension-field"mechanism was revealed by comparing the bending moment distribution of two typical cases,and the lateral resistant mechanism was determined by the parameter of infill plates only. When SCSWs resist lateral load in "diagonal tension-field"mechanism,low residual resistance may occur due to the "diagonal tension-field"can not be fully developed with the existence of corrugation. Secondly,based on the requirements of the flexural rigidity of columns of unstiffened flat steel shear walls,the influence of the flexural rigidity of boundary columns on the performance of infill corrugated plates was analyzed. It was revealed that with the increase of normalized aspect ratio,the effect of flexural rigidity of boundary columns was more significant. The corrugated infill plate could be considered to resist lateral load with"in-plate shear yielding"mechanism when the normalized aspect ratio λn≤0. 45. In this case,the requirements of the flexural rigidity of columns were small,the boundary columns with flexural rigidity EI≥0. 5 EI* were recommended. Infill plates with normalized aspect ratio λn≤0. 45 were recommended to ensure sufficient residual resistance. Finally,the influence of vertical load on the performance of infill plate in the range of λn≤0. 45 was analyzed. Observing the change of lateral resistance of infill plates when changing the axial pressure on columns,the fact that vertical load had little effect on the maximum resistance was revealed. But the residual resistance would drop due to the shear force of infill plates could not be fully developed when boundary columns had large vertical compression in residual state. With the increase of λn,the drop of residual resistance was more significant. This situation could be avoided by increasing the cross-sectional area of boundary columns.