三维过渡等参单元在岩土工程有限元分析中的应用

发布时间：2018-04-24 06:49

本文选题：岩土工程 + 有限元　；参考：《岩土力学》2015年05期

【摘要】：土石坝等复杂土工结构物有限元三维建模中多采用精度较高的六面体单元辅以部分过渡用的退化单元,而退化单元由于形态不好,会导致有限元计算精度较差。解决该问题的途径之一是采用过渡性的等参元。总结了几种常遇到的过渡等参单元(楔形体、四面体、金字塔)的插值函数和高斯积分局部坐标和权重,并编入了有限元程序。通过比较六面体单元和金字塔单元剖分理想土石坝的有限元计算结果,说明所引入的金字塔单元是满足精度要求的。将各种过渡单元应用于实际土石坝工程的有限元计算,结果表明,使用过渡等参单元是可以在一定程度上提高计算精度的。最后讨论了二次单元在弹塑性有限元动力计算中的应用。二次单元的使用,可以改善动力计算中的超静孔压分布,提高计算精度。
[Abstract]:In the finite element modeling of complex geotechnical structures such as earth-rock dams, the hexahedron element with high precision is usually used, which is supplemented by some transitional degenerate elements, and the degenerate element is poor in shape, which will lead to the poor accuracy of finite element calculation. One way to solve this problem is to adopt transitional isoparametric elements. The interpolation functions of several transition isoparametric elements (wedge, tetrahedron, pyramid) and the local coordinates and weights of Gao Si integral are summarized, and the finite element program is programmed. By comparing the finite element results of hexahedron element and pyramidal element in dividing ideal earth-rock dam, it is shown that the introduced pyramid element can meet the requirement of precision. All kinds of transition elements are applied to the finite element calculation of actual earth-rock dam engineering. The results show that the accuracy of calculation can be improved to some extent by using the transition isoparametric element. Finally, the application of quadratic element in elastoplastic finite element dynamic calculation is discussed. The application of secondary unit can improve the distribution of excess static pore pressure in dynamic calculation and improve the accuracy of calculation.
【作者单位】：清华大学水沙科学与水利水电工程国家重点实验室;
【基金】：国家自然科学基金资助项目(No.51379103,No.51179092) 国家重点实验室项目(No.2013-KY-4)
【分类号】：TU43

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