【作者】 杜春江；

【导师】 钱林方；

【作者基本信息】 南京理工大学 ， 机械设计及理论， 2008， 博士

【摘要】 连续体结构拓扑优化是目前结构优化领域研究的热点问题之一,相对于传统的尺寸优化和形状优化,拓扑优化处于结构的概念设计阶段,其结果是一切后续优化设计的基础,因而结构拓扑优化能够取得更大的经济效益,对于工程设计具有更重要的意义。本文分别对基于变密度法、渐进结构优化方法和多岛遗传算法的连续体结构拓扑优化方法及其中的数值计算问题进行了研究,利用大型有限元软件ANSYS强大的前后处理及计算功能,开发了以上三种方法的拓扑优化程序和用户图形化界面;对某自行榴弹炮的炮塔体进行了结构动态响应分析和优化,将拓扑优化方法应用到炮塔托架体的设计中,借助于优化来实现炮塔体轻量化设计。主要的研究内容包括:1、分别推导了结构体积和刚度约束下基于变密度方法和优化准则法的拓扑优化算法;提出了一种新的灵敏度过滤算法,有效消除了优化过程中的棋盘格和网格依赖数值问题;利用ANSYS软件强大的前后处理及计算功能编制了拓扑优化程序,以典型算例对其准确性进行了验证,并将其应用到二维和三维结构拓扑优化中,有利于促进连续体结构拓扑优化方法的工程应用研究;在以上研究基础上探讨优化参数对结果的影响;2、对基于结构应力和应变能的渐进结构优化方法和双向渐进结构优化方法进行了研究;分析了传统渐进结构优化方法中基于单元应变能的灵敏度计算方法产生较大误差的原因,提出了一种改进的灵敏度算法;为了改善优化过程中优化参数选取困难且对优化求解的稳定性存在较大影响的问题,提出了一种基于自适应参数的渐进结构优化方法;3、为了解决前面几种拓扑优化方法所存在的全局寻优问题,将多岛遗传算法应用到连续体结构拓扑优化中,以典型算例对比分析了基于标准遗传算法和多岛遗传算法的连续体结构拓扑优化方法,结果表明在相同参数下基于多岛遗传算法的拓扑优化方法能够获得更好的全局解;4、采用ANSYS二次开发语言APDL分别编制了以上基于变密度法、双向渐进结构优化方法和多岛遗传算法的拓扑优化程序,增强了ANSYS软件的拓扑优化功能,并利用界面二次开发语言UIDL完成了相应程序的界面菜单设计;5、将连续体结构拓扑优化方法应用到某车载炮驾驶室和某边防巡逻车车身结构优化设计,通过有限元方法实现了样机的虚拟设计改进,避免了设计的盲目性,提高了设计的可行性和有效性,从而缩短了设计周期;6、分析了某炮塔体结构在火炮发射过程中的动态响应特性,以轻量化设计为目的,基于多岛遗传算法对炮塔体各部分壁厚进行优化,并对优化后结构的刚强度进行了校核,壁厚优化后炮塔体质量减少了10.01%;对炮塔托架体结构进行拓扑优化,基于优化结果建立了托架体的模型,计算结果表明优化后的托架体在满足结构刚度约束要求下,质量减少了23.9%。更多还原

【Abstract】 Continuum structural topology optimization is one of the major subjects in structural optimization field. Comparing with traditional size and shape optimization, topology optimization is at the phase of structural concept design, and result of it is foundation for succeeding design, therefore, structural topology optimization can obtain more economic profit, and is more important to engineering design. In this thesis, continuum structural topology optimization methods based on density method、evolutionary structural optimization and multi-island genetic algorithm are studied respectively, develop the program of topology optimization and user graphic interface based on software ANSYS; dynamic analysis and optimization of some self-propelled howitzer turret is done, and the bracket body is optimized with topology optimization method, in order to realize the light-weight design of turret body.Main contents of this thesis include:1、Deduce the topology optimization algorithms under structure volume constraint and stiffness constraint based on density method and OC method respectively; put forward a new filter algorithm, eliminate the checkerboard and mesh-dependence problem in continuum topology optimization effectively; develop topology optimization program on the platform of ANSYS software, validate it with typical sample and apply it into continuum structural topology optimization successfully; discuss the effect of parameters to the result;2、Study the ESO and BESO method based on structure stress and strain energy; bring forward an improved sensitivity algorithm after analyzing error caused by the original algorithm in traditional ESO; put forward an evolutionary structural optimization method based on adaptive parmeters to solve the problem caused by parameters choosing;3、Apply multi-island genetic algorithm into continuum structural topology optimization, contrast of result from SGA and MIGA is done with typical sample, result shows that the continuum structural topology optimization based on MIGA can produce better global optimization solution with the same parameters;4、Develop the topology optimization program based on density method、bi-directional evolutionary structural optimization and multi-island genetic algorithm respectively with APDL, enlarge the function of topology optimization in ANSYS, and realized the user graphic interface design with UIDL;5、Apply the topology optimization method into cabin design of some truck-mounted howitzer and body structural optimization design of some patrol vehicle, realize virtual design and improvement of sample vehicle with the finite element method, avoid blindness in traditional design method and enhance the effectiveness;6、Analyze the dynamic response characteristics of some turret body during firing, optimization of body wall thickness is done based on the multi-island genetic algorithm with the purpose of light-weight design, and the weight reduced by 10.01%; topology optimization of turret body bracket is done, and bracket model is built referring to the optimization result, result shows that weight of the bracket body reduced by 23.9% after optimization, under the condition of satisfying the structure stiffness constraint.更多还原