计算物理 ›› 2003, Vol. 20 ›› Issue (1): 14-20.

• 论文 • 上一篇    下一篇

非均匀材料的应变软化及叠层复合材料破坏过程的数值模拟

陈永强1, 郑小平2, 姚振汉2   

  1. 1. 北京大学力学与工程科学系, 北京 100871;
    2. 清华大学工程力学系, 北京 100084
  • 收稿日期:2001-01-16 修回日期:2001-08-30 出版日期:2003-01-25 发布日期:2003-01-25
  • 作者简介:陈永强(1973-),男,山东,博士,从事固体力学方面的研究.

Explanation of Strain Softening and Numerical Modeling to the Failure Process of Laminated Composite Material

CHEN Yong-giang1, ZHENG Xiao-ping2, YAO Zhen-han2   

  1. 1. Department of Mechanical and Engineering Science, Peking University, Beijing 100871, China;
    2. Department of Engineering Mechanics of Tsinghua University, Beijing 100084, China
  • Received:2001-01-16 Revised:2001-08-30 Online:2003-01-25 Published:2003-01-25

摘要: 用有限元方法模拟了非均匀叠层材料的固体力学行为和破坏过程,各层材料性质的初始非均匀性采用某一给定的统计规则描述.用三维网格对试件进行有限元剖分,每个单元具有各自的均匀各向同性常量以反映总体的非均匀性.加载过程中不同单元破坏次序不同,因而整体等效应力应变关系表现出复杂的非线性性.通过数值计算,在选定的具体条件下,模拟了在逐步加载过程中,叠层材料应力应变场的变化和不同单元依次破坏直至试件整体破坏的过程.算例中叠层材料由14~15层构成,使用的网格数约为几千个.用该方法得到的非线性等效应力应变曲线与文[11,12]中叙述的拉伸作用下应变超过某一值后,材料发生应变软化现象的试验数据符合较好,趋势相当一致,因此可以设想是对应变软化原因的一种解释.

关键词: 非均匀性, 有限元方法, 统计分布, 叠层材料, 破坏过程

Abstract: The solid mechanical behaviors and the fracture process of laminated composite material with non-uniform material properties are simulated by the finite element method.All layers possess non-homogeneity, which is described by proper statistical distributions.In the 3-D discretization,the non-uniformity consists in a variety of elastic constants in each element.When the displacement or loading increases gradually, discretized element fails one by one randomly and the equivalent curve of strain vs. stress reflects complex non-linearity.Under the given conditions, the variation of strain and stress field and the fracture process are obtained through numerical simulations in which different elements fail in a random sequence until the specimen is fractured totally as the displacement or loading increases gradually. In the test runs, the material consists of about 14 to 15 layers. Thousands of elements are used in test examples presented in this paper. The relations between equivalent stresses and strain, got by simulation, is in qualitative agreement with test results in [11,12], especially for the phenomena of strain softening. Our investigations can serve as an explanation of strain softening of heterogeneous material.

Key words: heterogeneity, finite eiment method, statistical distribution, iaminated materiai, failure process

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