It is necessary to do a thorough research on the ultimate strength of cylindrical shells under the condition of crack growth to estimate and predict accurately bearing capacity of naval architecture and offshore structures with fatigue crack. In this paper, the effect of various parameters on the ultimate strength and its parameter sensitivity are analyzed through systematical calculation with existing theoretical analytic solutions based on the elastic-plastic crack and crack growth. The parameters include initial crack length, diameter thickness ratio, critical CTOD, critical CTOA, yield stress and Young's modulus. Besides, dimensionless parameters including loss coefficient of ultimate strength k, redundancy coefficient of strength A and residual length of crack extension f are introduced to assess the variation of carrying capacity of structure caused by crack growth. This paper provides a basic work for the assessment of effect of crack damage on the ultimate strength of the whole structure.%为了正确评价和预测大型海洋平台结构在疲劳裂纹损伤条件下的承载能力,须要全面、系统地研究圆柱壳这类基本构件在考虑裂纹扩展条件下的极限强度.针对含周向壁穿裂纹损伤的圆柱壳,利用已有的关于弹塑性裂纹及裂纹扩展的理论解析解,通过系列计算,探讨了裂纹初始长度、圆柱壳直径板厚比、材料的临界CTOD、临界CTOA、屈服应力及杨氏模量等参数对极限强度的影响,并就其对各参数的敏感度作了相应的分析.提出极限强度损失系数κ、强度冗余系数λ及裂纹剩余扩展长度ζ等无因次参数,并以此定量地评价由裂纹扩展所引起的结构承载能力的变化.这项研究为进一步合理地评估含裂纹损伤的结构系统整体的极限强度完成了一项基础性工作.
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