排序方式: 共有81条查询结果,搜索用时 324 毫秒
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建立了研究层状介质波动问题的时域边界元计算模型。为考察其精度和稳定性 ,对受冲击载荷作用的简单分层平板同时进行了动态光弹性和动态焦散线实验。由动态光弹性实验获取的系列双折射条纹相片反映出波动在层状介质中的传播、反射和透射特性 ,而动态焦散线实验为相应的时域边界元计算提供了精确的冲击载荷曲线。通过比较分别由实验和计算得到的在多个测点处双折射条纹级数的变化历程 ,对上述计算模型的适用性和可靠性进行了验证 相似文献
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介绍了盲孔-光弹贴片法的基本原理和测试方法,以及应用此法于某装置外壳,测定其进行VSR处理(即用激振方法来释放应力)前后构件内的余应力的变化情况。研究结果表明:进行VSR处理可以大幅度降低构件内的残余应力的总体水平,并使残余应力分布趋于均匀。 相似文献
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金玉澄 《海南大学学报(自然科学版)》1992,10(1):12-15
本文是参考文献[1]和[2]的补充和推广. 文[1]、[2]讨论了用有限元法修正平面问题不同泊松比μ值对光弹性实验结果的影响,提出了对网格划分细度是否是足够的一种有效的检验方法,但仅局限于静定支承的情况(实质上相当于应力边界条件),本文在此基础上进一步讨论了任意边界条件下的处理方法。 相似文献
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拓展了传统的光弹性应力冻结法,确立了三维有限变形光弹性的物理和实验基础,其结果可用在三维有限变形下橡胶类零件的应力分析,被分析对象的拉格朗日应变可达10%。 相似文献
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介绍了动光弹的基本原理,并从理论上回答了动光弹应用中的一些问题,如应力光学定律的适用范围,惯性力可否忽略等。同时,在总结回顾动光弹等差条纹级次判读方法的基础上,提出了把应力波理论与等差条纹分析判读相结合的方法,不仅使条纹判读的概念更清晰,而且可提高条纹分析和级次判读的准确性。 相似文献
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研究了精确光弹性模型的制作过程.用三维光弹性应力冻结切片法,分析了烟气轮机轮盘中心部位孔边的应力分布及沿孔轴线的变化规律.比较了原设计与改进设计两种方案中的最大工作应力,为改进结构设计提供了科学依据. 相似文献
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Wave propagation problems in orthotropic media are studied jointly by analytical and experimental methods in this paper. Dynamic orthotropic photoelasticity, which studies experimentally the dynamic behavior of orthotropic materials on a macroscopic scale by employing orthotropic birefringent materials, is established. A dynamic stress-optic law for orthotropic birefringent materials is postulated and practical methods of calibrating dynamic mechanical constants and dynamic stress-fringe values are proposed. Meanwhile, time domain boundary element method (BEM) for wave propagation in orthotropic media, is also presented based on the theory of elastodynamics. A scheme of stress calculations that is necessary for strength analysis is established. The paper stresses on the applications in wave propagation problems in orthotropic media by demonstrating three examples. The semi-infinite orthotropic plates with and without a circular hole modeled by a unidirectional fiber-reinforced composite under impact loading are analyzed. Time histories of birefringent fringe orders or stresses for specific points of the plates are obtained respectively from the two methods and compared with each other. Based on the above comparative study, the dynamic response of an underground workshop under seismic waves is studied by time domain BEM. The responses of displacements and stresses are solved. The effects of angle and frequency of incident waves and the degree of media anisotropy on dynamic response of the underground workshop are investigated. 相似文献
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