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