【作者】 谢小龙；

【导师】 杨德庆；

【作者基本信息】 上海交通大学 ， 船舶与海洋结构物设计制造， 2011， 硕士

【摘要】 本文研究了深海无人遥控潜水器(ROV)耐压电子舱结构设计中涉及的力学分析技术。利用有限元数值分析方法校核了耐压电子舱在深水条件下的强度、刚度与稳定性。根据深海耐压电子舱受力特点,优化其结构形式和尺寸,获得最优结构拓扑构型。对于耐压电子舱上下壳体接合面间接触问题,将非线性接触分析和简化分析法的计算结果进行比较。文中还探讨了加工误差与初始缺陷对耐压电子舱力学性能的影响。计算结果表明,本文耐压电子舱结构优选设计方案满足力学性能和重量要求,并且对加工误差与初始缺陷的影响不十分敏感。本文同样利用有限元数值分析方法校核了ROV载体框架在出水回收及甲板系固工况下的强度和刚度,结果表明本文设计方案下ROV载体框架满足使用要求。以金属-复合材料组合结构动力学设计问题为研究对象,建立了以材料类型(钢材、碳纤维层合复合材料)和结构尺寸为设计变量,振级落差、结构强度及位移约束条件下,结构重量最小化为目标函数的金属-复合材料组合浮筏结构材料选型优化设计数学模型。对提出的三种材料选型结构动力学优化模型进行了比较,采用遗传算法求解。研究表明,金属-复合材料组合结构确实能够得到比全金属结构或全复合材料结构更优异的减振降噪性能。鉴于材料选型优化模型求解的困难性,本文采用磨光函数法对该优化模型进行连续化,对构造出的六种不同形式磨光函数下优化模型计算结果与离散变量优化模型计算结果进行比较研究。结果表明,Sigmoid磨光函数、反正切函数和分段磨光函数应用于材料选型优化模型连续化的效果最佳。更多还原

【Abstract】 The mechanical analysis technologies involved in the design of pressured electric cabin for deepwater ROV are investigated. Finite element method is employed to verify the strength, stiffness and stability of pressured electric cabin. According to the surrounding load conditions, the topology and the sizes of the cabin are optimized and the optimal topology configuration is obtained. To investigate the contact mechanism of the joint surface between the upper and lower part of pressured electric cabin, the computation results are compared between nonlinear contact analysis and simplified analysis. In addition, the impact of mismachining tolerance and initial imperfection on the mechanical performance are discussed too. Computation results showed that the final design scheme satisfied the requirements on the mechanical properties and weight, and the mechanical properties are insensitive to the mismachining tolerance and the initial imperfection. Similarly, finite element method is employed to verify the strength, stiffness of ROV framework under retrieve and fixed condition. Caculation results showed that the design scheme satisfied the operating requirements.Materials selection optimization design for the steel-compostie hybrid structures under dynamics constraints is investigated. The material types (steel and composite material), elastic modules of the materials and structural sizes (thickness of the plate) in the steel-composite hybrid structures are defined as design variables respectively. Different mathematical optimization models with mixed continuous and discrete design variables are established under vibration level difference, stress and displacement constraints. The genetic algorithm is employed to solve the presented optimization problems. Computational results show high effectiveness of materials allocation than that of the common dynamics optimization with size design variables and single material. Because of the non-diiferential difficulties in the materials selection optimization problems, the polish function transformation method is applied for the continuity of the mathematical formulations. The optimization results of the proposed six polish function transformation models are compared with that of the discrete variable optimization model, it showed that Sigmoid polish function, arctan polish function and piecewise polish function are more suitable for the continuity of the mathematical formulations of materials selection optimization model.更多还原