甲板板格屈曲破坏下船体梁的可靠性计算

用结构可靠性理论来分析船体结构破坏是造船理论的又一发展,有着重要的意义。本文论述了由于甲板板格屈曲破坏而导致船体梁最终溃折的破坏方式,对用扶强材加强的板格在平面内压力作用下的三种失效模式以及相应的船体梁极限弯矩作了均值和变异的分析。本文还对构件尺寸、材料特性以及焊接残余应力等因素对板格和船体梁的影响,作了敏感性分析。本文分别以屈服和屈曲作为失效模式计算了两艘实船的失效概率。研究结果表明,在船体梁破坏中板格屈曲比屈服更易发生,这对我们令后进行船体结构系统分析有一定的参考价值。

Failure Probability of Ship Hull under Panel Collapse Modes

This paper studies the statistical characteristics of ship ultimate moment defined by strength deck panel collapse of symmetric or asymmetric stiffeners in either the column collapse mode,the tripping collapse mode or the coupled column-tripping collapse mode.Formulas have been derived for the determination of statistical characteristics in either explicit or implicit functions.Plate thickness,section area of stiffener,material yield stress,Young's modulus and welding residual stress are treated as independent random variables.The sensitivity of ship ultimate bending moment to the changes of these random variables are also discussed.And the failure probability of panel collapse mode has been compared with that of the tension yield mode for two ships.