共查询到20条相似文献,搜索用时 93 毫秒
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基于Kriging代理模型的结构形状优化方法 总被引:1,自引:0,他引:1
任何机械零件都是由结构尺寸和形状构成.通过常规设计手段,一般确定零件的整体结构尺寸,但大量局部的尺寸决定了零件形状.而零件的失效往往与零件形状是否合理密切相关.形状优化技术一般以有限元技术为基础,通过边界的迭代过程获得形状优化.文中结合试验设计技术和近似代理技术,利用少量样本点建立高精度分析模型,代替原有零件模型,在代理模型上寻找符合约束条件的结构参数,从而获得零件的形状优化.首先阐述了该优化方法的设计思想和理论基础,最后以六角钢盘的结构优化为例说明了该方法的具体应用过程. 相似文献
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研究基于灵敏度的电磁结构形状优化设计方法。针对以往用磁位作为状态变量不方便的情况,文中直接采用磁通密度为状态变量。在用直接法求解矢量磁位灵敏度方程的基础上,给出适合形状优化的磁通密度灵敏度分析的两种方法——半解析法和局部差分法。前者在磁通密度灵敏度计算中对形函数导数采用了差分近似,后者用一阶近似方法得到设计变量扰动后的矢量磁位和磁通密度,然后用差分法计算磁通密度灵敏度。两种方法简单且计算效率高,精度能够满足要求。优化问题求解采用序列线性规划算法。应用本文方法对电磁铁和同步电机磁极进行形状优化,取得了满意的结果。 相似文献
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建立了某款载重汽车平衡悬架系统橡胶弹簧的有限元分析模型,应用非线性分析软件ABAQUS对其垂向和侧向的非线性刚度进行了计算分析,得到的刚度曲线与试验结果具有很好的一致性,证明了分析方法的有效实用性.对极限工况下橡胶弹簧内部应力分布进行分析,根据分析结果对现有橡胶弹簧结构进行了结构优化,对优化后新结构进行了应力与应变分析,优化结果理想.该方法对平衡悬架系统橡胶弹簧的结构优化设计与计算具有很大的指导意义. 相似文献
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基于渐进结构均匀化拓扑优化的方法,以体积为目标函数,建立了梁结构的不同布局的拓扑优化模型.利用ESO方法的思想理论推导出梁结构拓扑优化的数学模型,并借助于ANSYS软件平台,利用APDL语言实现了优化算法.数值算例验证了该方法的可行性和有效性,它可减少设计变量的数目,提高求解效率. 相似文献
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An efficient approach for shape optimization of components 总被引:2,自引:0,他引:2
The optimization problem of finding the optimal shape of a mechanical component is investigated with the aim of presenting a simple and efficient numerical approach for minimizing stress concentration factor. The proposed approach is based on finite element method in conjunction with the widely used fully stressed design criterion (or the axiom of uniform stress), i.e. for structural shape optimization, an essential requirement for optimality is the achievement of constant tangential stresses along a section of the boundary to be optimized. The design boundary is modeled by using cubic splines, which are determined by a number of control points. The optimal shape of the design boundary with constant stress is achieved iteratively by adjusting the design boundary shape based on a simple logic and algorithm. The result quality in terms of accuracy and efficiency are tested and discussed with finite element analysis examples. The approach presented has the attractive properties that it can be very simply implanted into standard finite element codes. 相似文献
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三维弹性接触体形状优化问题的研究 总被引:6,自引:0,他引:6
以边界元法作为应力分析工具,对三维弹性体形状优化问题的研究进行了理论上的探讨,并研制了相应的计算机程序。对几个算例作了分析验证,得到了满意的结果。 相似文献
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一种实用的机械结构优化设计方法 总被引:19,自引:1,他引:18
提出一种实用的机械结构优化设计方法-ANSYS与导重准则结合法,该方法既能利用结构分析商用软件ANSYS有限元建模,分析求解与结果输出方便的优势,又能发挥结构优化理性准则法。导重法优化效果好,收敛快的优越性,一般只需约5~7次优化迭代计算,即可得到十分重要的优化效果。大大提高了设计效率坦与设计质量。其优越性与实用性在某双模轮胎硫化机的优化设计实践中得到充分验证。 相似文献
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采用了多种优化设计方法,以某悬架结构为例进行了结构优化设计方法研究.通过对车辆行驶工况和对车体空间布置的分析,建立了拓扑优化可设计域和非可设计域,完成了悬架结构的拓扑优化设计,并建立了工程结构.基于强度分布与应力干涉理论,将可靠性理论和优化方法相结合,进行了可靠性优化设计.其优化结果与尺寸优化和形状优化结果进行了对比,证明了优化设计方法的有效性和可行性,为工程结构提供了一种新设计思路. 相似文献
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Leaf-spring crossed flexure pivots are used in an increasingly large number of applications, many of which require the fatigue life and/or the rotational capability of the pivots to be maximized. Since these two qualities are determined by the endurance limit or the yield stress of the leaf-springs’ material, maximizing them will necessarily require reducing the stress levels arising in the aforementioned springs during operation. Partly for the sake of simplicity, partly due to manufacturing constraints, constant thickness leaf-springs have traditionally been used in crossed flexure pivots. However, minimizing stress simply by increasing the length or by decreasing the thickness of the leaf-springs is often not viable, either due to spatial constraints or to the attendant degradation in spring performance. This paper investigates the scope for stress reduction through shape optimization of the leaf-springs. To this end, a procedure combining a linear strain energy formulation, a parametric thickness profile definition and a series of optimization algorithms is employed. The resulting optimized thickness profiles are proven to be not only independent of the angular rotation at which the pivot operates, but also linearly scalable to leaf-springs of any length, minimum thickness and width. Validated using non-linear finite element analysis, the results show very significant reductions in relative maximum stress, of up to as much as 24% in the case of some pivot configurations. The optimized profiles and their corresponding constant thickness counterparts are also compared in terms of stiffness, strain energy and parasitic motion characteristics. It is concluded that shape optimization offers great potential for extending the fatigue life and/or rotational range of crossed flexure pivots. 相似文献
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Variants of the maximum separation method have become the de-facto methodologies for the characterisation of nanometre scale clusters in atom probe tomography (APT) data obtained from dilute solid solutions. All variants rely on a number of parameters and it is well known that the precise values for these parameters strongly influence estimates of cluster size and number density. Quantitative analyses require an improved understanding of the inter-relationship between user-defined parameters, experimental parameters such as detection efficiency and the resultant parameterisation of the microstructure.A series of simulations has been performed to generate clusters with a range of compositions (50-100%) and diameters (1.5-2.5 nm) in a dilute solid solution. The data were degraded to simulate the effects of the finite detection efficiencies and positioning uncertainties associated with the ECOPoSAP and LEAP-3000X HR.An extensive analysis of each resultant dataset, using a range of values for the maximum separation parameters was then performed. Optimum values for each material condition were identified and it is shown that it is possible to characterise cluster size, number density and matrix chemistry. However, accurate estimates of cluster compositions are more difficult and absolute measurements must be treated with caution. Furthermore, it is shown that DMAX must increase with decreasing detection efficiency and consequently clusters of a specific size will appear slightly larger in atom probes with a lower detection efficiency. 相似文献
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《Measurement》2016
A joint method based on the relative diameter is introduced for evaluating the minimum circumscribed circle and maximum inscribed circle in this article. The definition and calculation of the relative diameter is given in detail. The proposed method is an approximate method based on the least square circle solution, and just for the minimum circumscribed circle and maximum inscribed circle criteria. Several examples from the literatures have been carried out to validate the effectiveness of the proposed algorithm. 相似文献