复合材料薄壁加筋结构局部稳定性分析的谱单元法

The Spectral Element Method of the Local Stability for the Stiffened Thin-walled Structure of Composite

工程结构的有限元数值分析往往采用粗网格模型,这导致压、剪或其联合载荷作用下的薄壁加筋结构初始屈曲临界载荷计算误差过大,而采用四边简支板的工程校核方法强化了实际约束效应,进一步加大了误差。为此,采用p-收敛的升阶谱元法,计算复合材料四边简支及弹性支承层合板的屈曲特征值;同时提取粗网格单元的实际应力状态,对复合材料薄壁加筋结构局域初始屈曲临界载荷进行了分析计算。结果表明:谱单元方法可很好的收敛于四边简支板的理论解,计算效率较高;局域薄壁加筋结构的谱单元方法可高效收敛于整体薄壁加筋结构的局部稳定性解,且能计及加强筋对复合材料层合板的弹性支承作用,更准确的模拟了加筋板的实际约束效应。

Finite element analysis of engineering structures usually applies coarse grid models,which results in large error when calculating the initial critical buckling loads of stiffened thin-walled structures under in-plane pressure and shear loads. And by using the shell with four edges simply supported to check it strengthens the actual boundary conditions,which makes the error larger. With the help of the spectral element method,the buckling eigenvalue of the simply supported and elastically supported composite laminates is calculated respectively. Then by extracting the real stresses of the coarse grid model,the local initial critical buckling loads of stiffened composite thin-walled structure is analyzed. The results show that the spectral element method（ SEM） converges to the theoretical solution of the plate with four edges simply supported,which has high computational efficiency; SEM for local stiffened thin-walled structures can efficiently converge to the local stability solution of the overall reinforced thin-walled structures,and it can involve the elastically supporting effect of the composite plates,which better simulates the actual constraints of the stiffened plate.