This paper presents a study on the behavior of screw connections in sheathed cold-formed steel (CFS) walls. A finite element (FE) model with solid elements was developed to investigate different failure modes. Suitable solution techniques, element types, mesh sizes, screw modeling, and geometric and material non-linearity were considered in model development. Since the behavior of the sheathing boards is similar to that of other quasi-brittle materials, the Concrete Damage Plasticity (CDP) model was used to model the material behavior using both classical plasticity and continuum damage mechanics. Uniaxial experimental tests were performed on fiber-cement board samples to define material parameters used in the CDP model. The load displacement behavior, ultimate strength, and failure modes obtained from the developed FE model were validated against available experimental results on walls sheathed with cement or gypsum boards. The validated FE model was then used to perform parametric study to investigate the effect of different design parameters on the connection behavior. These parameters are: board type and thickness, CFS profile thickness, screw diameter, screw length, and edge distance. The results of the parametric study were used to develop a design equation for the screw connection strength using nonlinear regression analysis.

本文对带护套的冷弯型钢 (CFS) 墙中的螺钉连接行为进行了研究。开发了具有实体元素的有限元 (FE) 模型来研究不同的故障模式。在模型开发中考虑了合适的求解技术、单元类型、网格尺寸、螺杆建模以及几何和材料非线性。由于护板的行为类似于其他准脆性材料的行为，因此使用混凝土损伤塑性 (CDP) 模型来模拟使用经典塑性和连续介质损伤力学的材料行为。对纤维水泥板样品进行了单轴实验测试，以定义 CDP 模型中使用的材料参数。载荷位移行为、极限强度、从开发的 FE 模型中获得的失效模式和可用的实验结果在用水泥或石膏板覆盖的墙壁上进行了验证。然后使用经过验证的有限元模型进行参数研究，以研究不同设计参数对连接行为的影响。这些参数是：板类型和厚度、CFS 型材厚度、螺钉直径、螺钉长度和边距。参数化研究的结果用于通过非线性回归分析开发螺纹连接强度的设计方程。CFS 型材厚度、螺钉直径、螺钉长度和边距。参数化研究的结果用于通过非线性回归分析开发螺纹连接强度的设计方程。CFS 型材厚度、螺钉直径、螺钉长度和边距。参数化研究的结果用于通过非线性回归分析开发螺纹连接强度的设计方程。