楔形环连接结构可靠性优化设计研究

发布时间：2018-04-09 19:13

本文选题：楔形环连接结构　切入点：弹塑性分析　出处：《西南交通大学》2011年硕士论文

【摘要】：楔形环连接结构主要应用于鱼雷、导弹、航天飞行器以及水下航行器的壳体连接,其光顺的壳体表面可以提高此类产品在高速下的气动性能或液动性能,同时其在外载下的可靠性也与系统的功能实现直接相关。本文根据工程应用需求背景开展了楔形环连接结构的弹塑性有限元应力分析,确定了结构的失效模式,引入了分析设计的思想并采用应力分类法提出了结构的失效条件,在此基础上通过有限元正交试验构造了结构的二次响应面函数,继而建立并求解可靠度为约束的可靠性优化模型,得到了满足不同可靠性要求的更小型结构,为类似结构的设计研究提供了一条新思路。本文所取得的主要研究结果有以下几点： 1)壳体楔形环槽根部所在的截面是楔形环连接结构的薄弱环节,该处有较强应力集中和较大的由变形引起的弯曲应力。 2)楔形环腔根部是首先进入屈服的部位,该处的小范围塑性屈服不会引起整体结构的失效,只有当屈服区域扩展到整个截面时结构才会发生塑性垮塌失效。 3)引起楔形环连接结构失效的主要原因为危险截面处一次总体薄膜应力与一次弯曲应力,提出了由塑性材料所组成的楔形环连接结构的失效准则。 4)构造了结构应力响应与参数关系的二阶响应面函数,通过分析表明壳体口部止口长度是结构应力响应的主导因素。 5)结构的可靠性优化结果及检验结果说明优化后的结构优于原设计方案,满足了可靠度要求和小型化要求。
[Abstract]:Wedge-ring connections are mainly used in shell connections for torpedoes, missiles, aerospace vehicles and underwater vehicles, whose smooth shell surfaces can improve the aerodynamic or hydraulic performance of such products at high speeds.At the same time, the reliability of the system under external load is directly related to the realization of the system function.In this paper, the elastic-plastic finite element stress analysis of wedge-ring connection structure is carried out according to the requirement of engineering application, the failure mode of the structure is determined, the idea of analysis and design is introduced, and the failure conditions of the structure are proposed by using the stress classification method.On this basis, the quadratic response surface function of the structure is constructed by means of the finite element orthogonal test, and then the reliability optimization model with the constraint of reliability is established and solved, and a smaller structure satisfying different reliability requirements is obtained.It provides a new idea for the design of similar structures.The main results obtained in this paper are as follows:1) the section at the root of the wedge ring groove of the shell is the weak link of the wedge ring connection structure, where there is a strong stress concentration and a large bending stress caused by deformation.2) the root of the wedge-shaped ring cavity is the first to enter the yield position. The failure of the whole structure will not be caused by the small area of plastic yield, and only when the yield region is extended to the whole section will the failure of plastic collapse occur.3) the failure of wedge-ring connection structure is mainly caused by one total film stress and one bending stress at the dangerous section. The failure criterion of wedge-ring connection structure composed of plastic material is proposed.4) the second-order response surface function of the relation between the stress response and the parameters of the structure is constructed. The analysis shows that the length of the shell orifice is the dominant factor in the stress response of the structure.5) the results of reliability optimization and test show that the optimized structure is superior to the original design scheme and meets the requirements of reliability and miniaturization.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH131.5

【相似文献】