铝锂合金加筋壁板剪切屈曲性能

为研究剪切载荷下2A97铝锂合金加筋壁板的屈曲与后屈曲行为，设计了加筋壁板和夹具，完成了壁板的剪切试验；得到了加筋壁板的失稳载荷、破坏载荷以及破坏模式；采用受剪板屈曲与张力场理论计算了加筋壁板的剪切屈曲失稳载荷；建立有限元数值计算模型对加筋壁板屈曲行为进行计算分析，并将数值结果与试验结果对比。结果表明：加筋壁板的屈曲模式为筋条间蒙皮的局部屈曲；加筋壁板的破坏模式为沿加载对角线方向蒙皮的凸起，破坏原因为蒙皮的塑性变形、撕裂以及筋条的扭转变形；利用张力场理论可以得到较准确的屈曲失稳载荷，与试验误差为6.56%；数值模拟得到的屈曲与破坏模式与试验吻合，失稳载荷和极限载荷与试验结果误差分别为1.22%和11.52%。

Shear buckling performance of AI-Li alloy stiffened panels

To study the buckling and post-buckling behaviors of 2A97 Al-Li alloy stiffened panels under shear loads, 2A97 Al-Li alloy stiffened panels are designed and shear static tests are performed, obtaining the buckling load, failure load and failure mode of the panels. Buckling and tension field theories are adopted to calculate the buckling behavior of the stiffened panels under shear loading and the finite element method used to model and analyze buckling behavior of the stiffened panels, the numerical results of which are compared with the experimental results. It is shown that the buckling mode of the stiffened panels is the local buckling of the skin between the ribs; the failure mode is the bulge of the skin along the loading diagonal direction, which is caused by the plastic deformation and the tear of the skin and the torsion of ribs. A relatively accurate buckling load can be obtained by the tension field theory, with an error of 6.56% compared with the experimental results. While the buckling and the failure modes are consistent with those in the experiments, the buckling load and the ultimate load have errors of 1.22% and 11.52%, respectively.