舰载机壁板剪切后屈曲承载能力预测与试验验证

Post-buckling study and test verification of carrier-based aircraft wing stiffened panels under shear load

舰载机着舰撞击对机翼盒段产生巨大的扭矩,蒙皮以剪切形式承受扭矩,这是机翼壁板的重要设计工况。为准确预测加筋壁板剪切后屈曲承载能力,采用MSC.NASTRAN软件MRIKS弧长法,将线性屈曲分析的一致模态缺陷位移作为扰动引入后屈曲分析。考虑材料和几何双重非线性,对整体加筋壁板剪切试验件的后屈曲破坏过程进行模拟、对承载能力进行预测。根据剪切试验结果,进行对比分析。结果表明:有限元模拟的加筋板初始屈曲发生在蒙皮上,长桁足够大的相对刚度使得长桁与蒙皮连接线上出现屈曲节点,随着载荷增大,加筋壁板整体"坍塌",与试验现象一致。有限元分析(FEA)得到的初始屈曲载荷与试验结果的误差为1.25%,预测的极限承载载荷与试验破坏载荷的误差为2.4%。表明引入缺陷后的MSC.NASTRAN弧长法非线性后屈曲计算能够准确预测加筋壁板剪切后屈曲承载能力,为加筋壁板剪切试验和强度设计提供了分析方法。

The huge torque,beard by the stiffened panel and caused by the landing impact on the wing box section,is an important condition for the design of wing panels.To accurately predict the shear post-buckling capacity of the stiffened panel,the uniform mode defect displacement of liner bucking analysis is introduced as a disturbance to the post-buckling analysis by using the MSC.NASTRAN MRIKS arc-length method.Considering the geometric and material non-linearity,the post-buckling failure process of the shear specimen of the integrally stiffened panel is simulated and the carrying capability is predicted.Based on the test results,a comparative analysis is carried out,and the results indicate that the initial buckling of the stiffened panel occurs on the skin,and sufficient relative stiffness of the stringer produces the buckling node in the connecting line of the stringer and skin.As the load increases,the stiffened panel collapses,showing consistency with the test phenomenon.Compared with the results of the test,the error of the initial buckling load simulated with Finite Element Analysis(FEA)is about 1.25%,and the error of the failure load predicted with FEA is about 2.4%.So,the nonlinear post-bucking calculation based on the MSC.NASTRAN arc-length method with introduced defect can be used to accurately predict the load bearing capacity of the stiffened panel.The research provides an analytical method for the shear test and strength design of the stiffened panel.