含初始几何缺陷薄壁圆柱壳屈曲载荷的数值模拟方法研究

Research on Buckling Load Numerical Method of Cylindrical Shells with Initial Imperfection

对3个薄壁圆柱壳试件进行了轴压屈曲试验,得到了屈曲临界载荷值和屈曲变形。基于试验结果,比较了弧长法、非线性稳定算法和显式动力算法3种有限元数值模拟方法的差异,其中非线性稳定算法的模拟结果与试验结果吻合最好,该方法可以比较准确地计算轴压屈曲临界载荷,误差在6.0%以内,且屈曲变形与试验吻合得较好。试验表明,初始几何缺陷的存在大幅降低了薄壁圆柱壳的屈曲临界载荷,试验值仅为理论值的42%左右。

A buckling experimental investigation on the behavior of 3 cylindrical shells subjected to axial pressure was carried out. Through experimental investigation, the buckling critical loads and deformation were obtained. Based on the experimental results, three different nonlinear numerical calculation methods, including Riks method, nonlinear static method and explicit dynamic method, were compared. The numeri- cal calculation results show that the nonlinear static method and experimental results are in good agree- ment when taking the initial imperfection into account. This method can relatively accurately calculate the axial buckling critical load with lower than 6.0% error and shows consistent deformation with experimen- tal results. Experimental results indicate that due to the initial imperfection the axial critical buckling load was reduced largely and the experimental value of buckling loads is only about 42% of the theoretical value.