适用于UH模型的单元破坏修正方法

发布时间：2018-03-23 08:15

  本文选题：UH模型　切入点：UMAT　出处：《北京航空航天大学学报》2017年04期 　论文类型：期刊论文

【摘要】：在采用UH模型的用户材料子程序(UMAT)进行有限元计算过程中时常会出现局部单元破坏的情况,主要包括拉裂和剪坏,这种破坏应力状态的存在不仅会使得计算结果不合理,也会降低有限元计算的稳定性。针对采用UH模型UMAT进行有限元计算时遇到的局部单元破坏问题,根据一定的假设条件,并结合不同坐标系下的应力变换关系,推导得到适用于UH模型的三维问题单元破坏修正公式;采用FORTRAN语言编写出相应的子程序,将其嵌入UH模型UMAT中,以消除采用UH模型进行有限元计算时出现的不合理的破坏应力状态,提高UH模型UMAT有限元计算的稳定性,并通过有限元模拟基坑开挖的例子验证本文所提的单元破坏修正方法的有效性和合理性。
[Abstract]:In the process of finite element calculation using UH model subprogram Umatt, the local element failure often occurs, mainly including tensile crack and shear failure. The existence of such failure stress state will not only make the calculation results unreasonable. The stability of finite element calculation will also be reduced. According to certain assumptions and combined with the stress transformation relations in different coordinate systems, the local element failure problem encountered in finite element calculation with UH model UMAT is discussed. The three dimensional problem element failure correction formula for UH model is derived, and the corresponding subprogram is written in FORTRAN language, which is embedded in UH model UMAT. In order to eliminate the unreasonable failure stress state when UH model is used for finite element calculation, the stability of UH model UMAT finite element calculation is improved. The effectiveness and reasonableness of the element failure correction method proposed in this paper are verified by the finite element simulation of foundation pit excavation.
【作者单位】： 北京航空航天大学交通科学与工程学院;
【基金】：国家“973”计划(2014CB047001) 国家自然科学基金(51579005,11272031)~~
【分类号】：TU43
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本文编号：1652626