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In conjunction with the homogenization theory and the finite element method, the mathematical models for designing the corss-section
of composite shafts by maximizing the torsion rigidity are developed in this paper. To obtain the extremal torsion rigidity,
both the cross-section of the macro scale shaft and the representative microstructure of the composite material are optimized
using the new models. The micro scale computational model addresses the problem of finding the periodic microstructures with
extreme shear moduli. The optimal microstructure obtained with the new model and the homogenization method can be used to
improve and optimize natural or artificial materials. In order to be more practical for engineering applications, cellular
materials rather than ranked materials are used in the optimal process in the existence of optimal bounds for the elastic
properties. Moreover, the macro scale model is proposed to optimize the cross-section of the torsional shaft based on the
tailared composites. The validating optimal results show that the models are very effective in obtaining composites with extreme
elastic properties, and the cross-section of the composite shaft with the extremal torsion rigidity.
The project supported by the National Natural Science Foundation of China (10172078 and 10102018) 相似文献
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吴长春 《数学的实践与认识》1974,(1)
在土木、建筑工程的施工中,常遇到圆弧曲线的现场放样问题,即已知弦长和拱高,求作圆弧大样.这类问题看起来很简单,但是在实际上,由于各种施工条件的限制,不可能象几何作图那样,圆规一转就出来了.例如,在剧场工程中(图1),观众席位根据建筑设 相似文献
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This paper describes an incompatible finite element model satisfying the consistencycondition of energy to solve the numerical precision problem of finite element solution inperfectly plastic analysis.In this paper the reason and criterion of the application of themodel to plastic limit analysis are discussed,and an algorithm of computing plastic limitload is given. 相似文献
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This paper presents a new quadrilateral nonconforming finite element.We deal with itsconvergence by using generalized patch test.The error on stresses and displacements areobtained and numerical computations for plane elastic problems are given. 相似文献
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电子自旋共振(ESR)结合自旋探针方法研究高聚物体系已有大量报道,而目前应用于高聚物的拉伸过程研究仅限于静态测试,即样品先经拉伸后再被转入到ESR仪中测定。对一些具有快速松弛特性的材料研究,静态测试技术有着很大的误差和局限性。虽然可直接从国外引进ESR仪的拉伸裂置,但费用昂贵,同时由于设备结构复杂,拆装不能灵活,故使测定工作也受影响。 相似文献
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复合材料周期性线弹性微结构的拓扑优化设计 总被引:16,自引:4,他引:16
提出复合材料周期性线弹性微结构拓扑优化设计的模型,模型1设计具有极值弹性特性的复合材料,模型2设计工况最刚微结构单胞。通过该模型和均匀化技术可以获得优化的微结构单胞,进而改善或者得到最优宏观特性的复合材料。为了便于制造和应用,用胞体材料而不是多相材料来得到复合材料的极值弹性特性和最大刚度。优化结果表明,该模型与数值方法相结合可以有效地实现微结构的拓扑优化设计。 相似文献
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采用非协调元的连续体拓扑优化设计 总被引:15,自引:1,他引:15
介绍了满足分片检验条件的一种非协调元,推导了结构拓扑优化设计中数值计算和敏度分析的基本方程,给出了数值算例,并对协调等参元和非协调元的拓扑优化结果进行了对照,最后的优化结果表明:采用非协调元所得的优化解已经能够使用,如果再实施过滤技术,设计区域中的中间密度单元明显减少,优化结果会更加精致;使用两类单元的求解效率和优化迭代次数相近;非协调元比等参元具有更高精度的拓扑优化结果。能进一步克服棋盘格式。 相似文献
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将参变量变分原理引入铁电问题。对一类借用了经典弹塑性理论中的概念和方法的多轴铁电模型建立基于Helmholtz自由能的参变量变分原理,可以有效处理传统变分原理中由非关联流动法则或屈服面不考虑材料系数变化所引起的切线模量非对称困难。相应于参变量变分原理,引入参数二次规划算法,可获得具有可靠数值稳定性的一套铁电算法。将该算法应用于一个具体的铁电模型,数值计算结果表明本文方法的有效性。 相似文献