组合初始缺陷对含裂纹加筋板极限强度的影响研究

Research on the Influence of Combined Initial Imperfectionson the Ultimate Strength of Cracked Stiffened Panel

通过非线性有限元分析,研究初始变形、焊接残余应力等初始缺陷的组合作用对含不同位置裂纹的加筋板极限强度的影响,并分析了计算结果.研究结果表明:相同裂纹长度条件下,初始变形和残余应力的水平越高,含裂纹加筋板极限强度越低;仅考虑初始变形时,含双筋处板上裂纹的加筋板极限强度最高;随着残余应力水平的提高,含单边裂纹的加筋板极限强度下降幅度最小,含双筋处板上裂纹的加筋板极限强度降低幅度最大;随着裂纹长度的增加,残余应力会减小含单边裂纹加筋板的极限强度下降幅度,加剧含双筋处板上裂纹加筋板极限强度的下降.

Through nonlinear finite element analysis,the combined effects of initial imperfections such as initial deformation and welding residual stress on the ultimate strength of cracked stiffened plate at different positions were studied,and the calculation results were analyzed.The results show that under the same crack length,the higher the initial deformation and residual stress level,the lower the ultimate strength of cracked stiffened plate.When only the initial deformation is considered,the ultimate strength of cracked stiffened plate on the plate with double stiffeners is the highest.With the increase of residual stress level,the ultimate strength of stiffened plate with one-edge crack decreases the least,and that of stiffened plate with cracks on plate located at two stiffeners decreases the most.With the increase of crack length,residual stress will reduce the decrease of ultimate strength of stiffened plate with one-edge crack,and aggravate the decrease of ultimate strength of stiffened plate with cracks on plate located at two stiffeners.