Studies of Ship Structural Design Based on Reliability Engineering

并与现有的仅基于安全系数的优化设计方法进行了比较。数值模拟表明，在保证结构可靠度指标不变的情况下，该方法可使结构重量减轻。建立了疲劳强度设计程序，并将可靠性工程引入到该程序中。在此基础上，对船体结构的疲劳损伤进行了分析，并提出了损伤因子和安全指标的准则。编制了大变形弹塑性有限元程序，讨论了所采用的本构方程对数值解的影响，并进行了L形肋加固矩形薄板弯曲试验，研究了大变形行为。并与有限元解进行了比较，根据波浪载荷的估算，对纵边架的疲劳强度进行了评估，伊雷古 ...更多信息 并通过对实际船舶在海上发生的舷侧损伤的分析比较，验证了该评估方法的有效性。提出了一种基于极限强度的船舶结构可靠性分析方法，该方法采用矩阵法和塑性节点法自动生成相应的失效模式及其方程，并采用概率倒塌分析和失效模式分析相结合的方法进行结构可靠性评估。通过参数研究，讨论了某些设计参数的变化对结构可靠性的影响，并考虑了船舶结构壁板压缩破坏强度的可靠性分析。计算了桥面板和底板的失效概率。对于既承受面内压缩荷载又承受侧向水压力的底板，其破坏屈曲模式发生了明显的变化，建立了有限元分析可靠性的数值计算方法。将该方法应用于船舶结构分析。编制了一个辅助结构优化设计的专家系统。为了考虑可靠性，在知识库中增加了几种技术。少

The Present method is compared with the existing optimal design method based only on safety factors. Numerical simulation reveals that the present method leads to lighter structure with the same reliability index. The fatigue strength design procedure has been formulated, and reliability engineering is introduced to the procedure. Then, fatigue damages of ship structures are analyzed by these, and criteria for a damage factor and safety index are proposed for these procedures. The finite element program is developed for largely deformed elastoplasticity, and the effects of the utilized constitutive equation on numerical solutions are discussed.Also, the experiments of thin rectangular plate reinforced by L-shaped ribs under the action of bending are carried out to investigate large deformation behaviors, and compared with the finite element solutions.The fatigue strength of the longitudinal side frames has been assessed under the estimation of wave loads applied to ship sides in irregu … More lar waves, and the effectiveness of this assessment is verified in comparison of analyses of actual ship side damage occurring at sea. The method has been developed for performing reliability analysis of ship structures based on ultimate strength, which automatically generates relevant failure modes and their equations by using a matrix method and a plastic node method.Structural reliability assessments are carried out by using the method in which probabilistic collapse analysis and failure mode analysis are combined. Effects of some design parameter alteration on structural reliability are also discussed through parametric studies.Reliability analysis of compressive collapse strength for ship structural panels are taken into consideration here. Probability of failure for deck plates and bottom plates are calculated. As for bottom plates which are subjected to not only compressive in-plane load but also lateral water pressure, it becomes clear that collapse buckling modes change.Numerical method for evaluating a reliability of finite element analysis has been established. The method was applied in ship structure analysis. An expert system aiding optimal structure design was coded. Several techniques have been added to a knowledge base in order to consider reliability. Less