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传统可靠性设计难以符合现代设计要求,对舱体进行稳健性优化设计,可提高其综合可靠性。基于基体破坏和纤维断裂两种失效模式,采用验算点法求解复合材料单层可靠度。基于最终层失效假设,提出把结构看作由串联子系统组成的并联系统的思想,结合材料刚度比率退化准则和单层可靠度理论,采用概率逐步失效分析方法,计算出主要失效链,从而得出结构的失效概率。复合材料舱体设计变量复杂,提出二级优化方法思想:一级为系统级布局优化,对加强筋截面形状、位置确定等参数进行优化;二级为子系统级尺寸优化,对筋截面尺寸、复合材料各铺层厚度等参数进行优化。采用自适应随机搜索遗传算法,以复合材料舱体质量最小为目标函数,以可靠度要求为约束条件,采用稳健性协调优化方法,对存在初始缺陷的复合材料舱体进行稳健性优化,为复合材料结构优化设计提供参考。
The traditional reliability design is difficult to meet the requirements of modern design, the robust optimization of the cabin design, can improve its overall reliability. Based on two failure modes of matrix failure and fiber fracture, the reliability of single layer of composite material was calculated by check point method. Based on the assumption of failure of the final layer, the idea of considering the structure as a parallel system composed of tandem subsystems is proposed. Based on the material stiffness ratio degradation criterion and the single-layer reliability theory, the main failure chain is calculated by the method of probability failure analysis. The probability of failure of the structure. The design variable of composite material cabin is complex, and the idea of second-level optimization method is put forward: First-class is system-level layout optimization, which optimizes parameters such as cross-section shape and position of stiffener; second- Composite materials, such as the thickness of each layer to optimize the parameters. The adaptive random search genetic algorithm is used to optimize the robustness of composite material pods with the minimum mass of composite material as the objective function and the reliability requirement as the constraint condition. Material structure optimization design for reference.