液化场地堤坝地震响应的自适应步长法数值模拟

发布时间：2018-01-20 08:59

本文关键词： 自适应步长法后验误差评估堤坝地震液化　出处：《水利学报》2014年09期 　论文类型：期刊论文

【摘要】：土体在地震液化过程中表现为较强的材料非线性,此时动力数值分析中时间步长过大必然导致较大的误差。本文在水土耦合弹塑性有限元法和Newmark时域离散法的显式动力液化数值分析平台上,引入时域离散后验误差评估方法,并基于误差评估结果进行了时间步长的自适应调整,建立了基于自适应时间步长的液化动力数值分析方法,并将此方法应用于液化场地堤坝的地震响应数值模拟。通过分析堤坝算例,对比了自适应时间步长法和固定时间步长法计算的堤坝变形、超孔隙水压力比和平均相对误差等的变化规律。结果表明自适应时间步长法在土体动力液化显式数值分析中可以获得较高的计算精度,同时也可以提高计算效率、节省计算时间。
[Abstract]:In the process of earthquake liquefaction, soil mass exhibits strong material nonlinearity. In this case, the excessive time step in the dynamic numerical analysis is bound to lead to large errors. This paper is based on the explicit dynamic liquefaction numerical analysis platform of the soil and water coupling elastoplastic finite element method and Newmark time domain discrete method. The time domain discrete posteriori error evaluation method is introduced, and the adaptive time step is adjusted based on the result of error evaluation, and the numerical analysis method of liquefaction dynamics based on adaptive time step is established. The method is applied to the numerical simulation of the seismic response of the levees in liquefaction sites. By analyzing the examples of the levees, the deformation of the dams calculated by the adaptive time step method and the fixed time step method is compared. The results show that the adaptive time step method can obtain high accuracy in explicit numerical analysis of soil dynamic liquefaction. At the same time, it can also improve the calculation efficiency and save calculation time.
【作者单位】：大连理工大学海岸与近海工程国家重点实验室;大连理工大学岩土工程研究所;德岛大学岩土工程研究所;
【基金】：国家高技术研究发展计划863资助项目(NO.2012AA112510)
【分类号】：TU435
【正文快照】： 1研究背景在土木工程领域,有限单元法是重要的数值计算方法。在有限元计算中,提高计算的精度要从误差来源入手,如物理模型的误差、数值离散误差和舍入的误差等。其中物理模型误差可以通过改进材料本构模型来降低;舍入误差则不好克服。有限元离散误差可通过改进有限元算法来实

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