填充石膏基轻质材料的冷弯型钢复合墙体受剪承载力分析

为研究填充石膏基轻质材料的冷弯型钢复合墙体受剪承载力的计算方法，对2片空腔墙体和9片填充式墙体足尺试件进行低周往复加载试验，研究墙体在水平荷载作用下的破坏模式，结果表明:空腔墙体的破坏模式为墙面板与龙骨之间的螺钉连接破坏，进而导致墙面板蒙皮作用的失效；填充式墙体的失效模式分为两种:填充材料角部的受压破坏和冷弯型钢立柱的弯曲破坏。基于上述破坏模式，考虑墙面板蒙皮作用和填充材料支撑作用的影响，根据极限平衡理论，提出基于叠加法的受剪承载力计算模型，建立受剪承载力计算公式，该模型能反映自攻螺钉连接强度、填充材料强度和冷弯型钢龙骨强度对墙体受剪承载力的影响；理论计算值与试验值的比值在0.947~1.112，结果吻合较好。

STUDY ON SHEAR BEARING CAPACITY OF COLD-FORMED STEEL COMPOSITE WALLS WITH LIGHTWEIGHT GYPSUM FILLINGS

In order to calculate the shear bearing capacity of cold-formed steel (CFS) composite walls with lightweight gypsum infillings, the full scale specimens including two unfilled walls and nine infilled walls were tested under reversed cyclic loading. The failure modes of the walls under horizontal loads were studied. The test results show that the failure modes of unfilled CFS walls are characterized by the screw connections between sheathings and CFS frames, thus causing the loss of stressed skin provided by sheathings. There are two possible failure modes of CFS walls with fillings. One is the compressive failure at the corner of gypsum fillings, and the other is the flexural failure of CFS studs. According to above-mentioned failure modes and limit equilibrium theory, a shear bearing capacity calculation model based on superposition method is proposed considering the contributions of sheathings and infill materials. Then the calculation equations of shear bearing capacity are also derived. The model can reflect the impact of screw connections strength, infill material strength and CFS frames strength on shear bearing capacity of the walls. The ratios of the theoretical calculation values to the test values are between 0.947 and 1.112, which demonstrates that the theoretical calculation values have a good agreement with tests values.