复合材料帽形加筋壁板剪切屈曲性能

对碳纤维增强树脂基复合材料（CFRP）帽形加筋壁板的剪切屈曲进行了试验、理论分析和数值模拟。根据线弹性理论推导了复合材料帽形加筋壁板蒙皮的应变分布；针对复合材料帽形加筋壁板3种蒙皮板条单元截取宽度和两种边界条件，利用理论公式和半经验公式计算了加筋壁板的剪切屈曲载荷；利用特征值法和几何非线性法进行了剪切屈曲模拟分析；将得到的分析结果与试验结果进行了对比。结果表明：根据线弹性理论得到的蒙皮应变分布与试验结果一致，验证了推导结果的正确性；选择合适的边界条件和蒙皮板条单元截取宽度，利用理论公式和半经验公式可得到加筋壁板较准确的屈曲载荷；利用特征值法得到的屈曲载荷较试验屈曲载荷高，选择合适的几何初始缺陷系数利用几何非线性分析方法可模拟复合材料帽形加筋壁板在剪切载荷作用下的屈曲过程。

Shear buckling performance of composite hat-stiffened panels

The shear buckling of the Carbon Fiber Reinforced Polymer composite (CFRP) hat-stiffened panels is studied through experiment, theoretical analysis, and numerical simulation. Composite hat-stiffened panels are tested via the distributed load technique. The strain distribution of the skin of composite hat-stiffened panels is deduced based on the composite linear elasticity theory under shear load. Theoretical and semi-experiential approaches are proposed to predict the initial buckling load of hat-stiffened panels with two boundary conditions and three strip widths of skin. Finite element analysis is used to simulate shear buckling with the eigenvalue analytical method and the geometrical nonlinearity method. The analytical results and experimental results are compared. The results show that the strain distribution of skin of panels and test data are consistent, which verifies the effectiveness of strain formula of skin. Adopting theoretical and semi-experiential approaches, a relatively accurate shear buckling load can be obtained with proper boundary conditions and strip widths of the skin. The buckling load derived through the eigenvalue analytical method is higher than the experimental load. The buckling process can be simulated with appropriate initial imperfection through the geometrical nonlinearity method.