共查询到17条相似文献，搜索用时 187 毫秒
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采用水平集方法描述结构的拓扑及其变化,使用紧支径向基函数对计算区域的水平集进行插值以得到参数化的水平集方法。针对给定体积约束下结构最小柔度的拓扑优化问题,推导了目标函数对插值系数的灵敏度及拓扑优化的迭代格式,数值计算表明,使用该方法进行结构拓扑优化得到的结果边界形状光滑连续且计算稳定性较好。 相似文献
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通过修正材料插值模型和引入应力均方差作为性能收敛指标,改进了基于von Mises应力的双向渐进结构拓扑优化(Bi-directional Evolutionary Structural Optimization, BESO)方法,并结合Abaqus有限元软件及MATLAB语言编程实现了该算法;在此基础上,优化设计了集材绞盘机摩擦卷筒,得到不同材料体积分数、不同旋转周期数时,摩擦卷筒的最优拓扑结构,在减轻质量的同时,降低了应力集中水平。优化结果对实现集材绞盘机摩擦卷筒轻量化设计具有工程指导意义。 相似文献
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徐振洋 《赤峰学院学报(自然科学版)》2015,(5)
本文介绍了一种利用材料双光子吸收效应进行三维微结构加工的新型三维微结构加工技术,并对其原理进行了阐释。并在总结实验经验的基础上,对于一个简单的FFT模型(Four-Foot Table Model)进行了双光子三维微结构材料的光刻制作,并用三维电磁场仿真软件CST对结果进行了模拟。 相似文献
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以某高强化柴油机活塞为研究对象，采用拓扑优化方法和适度隔热技术来达到活塞的轻量化及隔热要求。将气隙隔热、陶瓷垫片隔热、组合活塞等隔热结构应用于经拓扑优化的铝合金活塞中。选取活塞顶部材料、顶部材料厚度、气隙半径和隔热片当量导热系数这4种主要影响因素进行正交实验设计和极差分析，确定影响活塞温度的显著性因素。采用满意度评价函数对各组合隔热方案进行满意度评估，从中筛选出最优方案，并对其进行热流分配分析和热应力计算。经过多学科协同教学和数值仿真训练，不仅促进了学生对专业知识的消化吸收，而且提升了学生的实践创新能力。 相似文献
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针对构件结构静动态特性研究中如何有效确定优化设计对象、衡量优化设计结果的问题,引入了比刚度结构效能概念,提出了构件比刚度结构效能提升设计方法和步骤。从三个方面探讨了构件比刚度结构效能提升设计方法:一是量化构件结构静动态特性,通过比刚度结构效能概念把构件的质量、最大变形量和固有频率及构件材料的弹性模量这4个重要特性指标进行整合,得到比刚度结构效能数值,从而量化构件结构静动态特性;二是综合运用拓扑优化和多目标优化,找出优化设计对象,优化构件结构;三是计算构件动态比刚度结构效能数值和静态比刚度结构效能数值验证构件比刚度结构效能的提升。通过把比刚度结构效能提升设计方法应用到龙门机床动横梁构件优化设计中,优化后的动横梁构件静态比刚度结构效能数值平均提升了41.2%,动态比刚度结构效能数值提升了5.5%,验证了构件比刚度结构效能提升设计的有效性。 相似文献
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张晓东 《天津职业院校联合学报》2013,15(4):100-103,121
桁架结构优化根据其设计变量类型和优化层次的不同,可大致分为尺寸优化、形状优化和拓扑优化。在优化设计过程中,一旦建立了优化模型,那么根据模型中变量、目标函数以及约束条件的特点选择合适的优化算法就成为可能,这是较快速、较准确地得到结果的关键问题。目前一些基于进化、模糊和人工神经网络等智能优化算法被逐渐应用到桁架结构拓扑优化中。 相似文献
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该文对稳态随机激励下结构阻尼系统的拓扑优化问题进行了研究，提出了一种基于虚拟激励法的拓扑优化方法 .该方法中，自适应地确定用于模态叠加的低阶模态的数量.未知高阶模态的贡献由迭代算法近似得到.由于该方法可以提供结构响应解的近似显示表达式，不仅可以增强灵活性，还可提高计算效率.文中给出了数值算例，从计算精度和效率两个方面证实了该方案的有效性. 相似文献
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《浙江大学学报(A卷英文版)》2016,(12)
目的:振动在机械结构的工作中难以避免,且会显著降低机械结构的工作性能。因此,结构动力响应优化设计就显得尤为重要。本文旨在提出一种有效的简谐力激励下的结构拓扑优化方法,通过合理设计结构内加强筋的布局,减小结构特定位置处的位移响应幅值,提高结构的固有频率。概要:植物叶脉可以有效地支撑叶片以抵抗自然界中的风载。本文将植物叶脉分叉构型的最优性用于简谐力激励下结构的加强筋布局设计。首先对简谐力激励下结构的位移响应进行分析。在此基础上,构建以最小化结构特定位置处位移响应幅值为目标的生长式拓扑优化模型。然后,从数学优化的角度,分析加强筋的生长应遵循的规律,提出生长式拓扑优化的数值实现算法。最后通过数值算例证明了本文所提方法的有效性。 相似文献
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以商用车空气悬架C型梁为研究对象,采用材料替换并结合拓扑和尺寸优化的方法进行轻量化设计。基于变密度法,以结构刚度最大化为目标进行拓扑优化,获得结构初始构型。在拓扑优化结果的基础上,综合考虑3种工况,以板件厚度为设计变量,各工况下的应力和变形为约束条件,质量最小化为目标,进一步进行尺寸优化。优化结果表明,设计方案满足结构刚强度要求,降低了结构的质量,达到了轻量化的效果。 相似文献
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A multi-objective optimization of non-uniform beams is presented for minimum radiated sound power and weight. The transfer matrix method is used to compute the structural and acoustic responses of a non-uniform beam accurately and efficiently. The multi-objective particle swarm optimization technique is applied to search the Pareto optimal solutions that represent various compromises between weight and sound radiation. Several constraints are imposed, which substantially reduce the volume fraction of feasible solutions in the design space. Two non-uniform beams with different boundary conditions are studied to demonstrate the multi-objective optimal designs of the structure. 相似文献
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The aim of this study is to explore the potential of various plant ramifications as concept generators for creating a brand topology optimization solution for stiffness design of continuum structures under harmonic force excitations. Firstly, a mathematical model is built to identify analytical laws that underlie the optimality of the effective but individual design rules of existing leaf venation morphogenesis. Then, a new evolutionary algorithm is developed to find the optimal topology of stiffened structures under harmonic force excitations. Candidate stiffeners are treated as being alive, growing at locations with a maximum displacement response gradient along the structural surface. Since the scale of the candidate stiffeners can be adaptively expanded or reduced during the simulation, computational resources could be saved, thereby enhancing the flexibility of topology optimization. Finally, the suggested approach is applied to a case study in which the displacement amplitude at specified locations is defined as the objective and the volume of added stiffeners as the constraint. The simulation process shows how the stiffness design of continuum structures can be conducted automatically using this bionic approach. 相似文献
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To reduce the environmental impact of mechanical parts, an approach integrating structural design and material selection was studied. Adding the discrete variable of material, a hybrid optimization model was built with the aim of minimizing environmental impact and based on an ordinary structure optimization model. An optional material set was built by combining measures of qualitative and quantitative screening, while the lifecycle environmental impact of the materials was quantified using the method of Eco-indicator 99. Two groups of structurally optimal solutions were calculated with ideal and negative-ideal materials selected respectively, and then the hybrid model was simplified by comparing the solutions. A material environmental performance index was calculated using an analytic method. By comparing this index for every material in the optional material set, the optimal material can be found and the structural solutions calculated. This method was applied to a dowel bar design process as a case study. The results show that the environmental impact of each material has a significant effect on the optimal structural solution, and it is necessary to study the integration of structural design and material selection. 相似文献
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Numerical Derivation of Strain Rate Effects on Material Properties of Masonry with Solid Clay Bricks
In this paper, numerical method is used to study the strain rate effect on masonry materials. A typical unit of masonry is selected to serve as a representative volume element (RVE). Numerical model of RVE is established with detailed distinctive modeling of brick and mortar with their respective dynamic material properties obtained from laboratory tests. The behavior of brick and mortar are characterized by a dynamic damage model that accounts for rate-sensitive and pressuredependent properties of masonry materials. Dynamic loads of different loading rates are applied to RVE. The equivalent homogenized uniaxial compressive strength, threshold strain and elastic modulus in three directions of the masonry are derived from the simulated responses of the RVE. The strain rate effect on the masonry material with clay brick and mortar, such as the dynamic increase factor (DIF) of the ultimate strength and elastic modulus as a function of strain rate are derived from the numerical results. 相似文献
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在分析传统混凝土两相复合材料弹性模量计算模型的基础上,考虑再生骨料中老旧砂浆含量的影响,分析水泥砂浆的体积与新天然骨料体积分数、再生骨料体积分数和再生骨料替代率之间的关系,建立预测再生混凝土弹性模量的三相复合材料模型。开展了不同龄期下不同骨料替代率再生混凝土弹性模量测试的试验研究,并采用所建立的各个复合材料模型与试验结果进行对比分析,建议了最适合再生混凝土弹性模量计算的复合材料模型,给出了随龄期变化时再生混凝土弹性模量的变化规律。 相似文献
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This paper presents the topology optimization design of structures composed of plane stress elements. The authors' proposed
method of topology optimization by virtual laminated element is based on the Evolutionary Structural Optimization (ESO) method
of linear elasticity, but dose not require formation of as many elements as the conventional ESO method. The presented method
has the important feature of reforming the stiffness matrix in generating optimum topology. Calculation results showed that
this algorithm is simple and effective and can be applied for topology optimization of structures. 相似文献