脆性基体复合材料层板弯曲破坏的数值模拟

讨论了复合材料层板的弯曲破坏问题,纤维层是正交异性弹性体,而基体为脆性损伤材料。提出了一种脆性损伤模型,虽是各向同性连续损伤模型,但利用等效损伤应变的定义,可以区分拉、压和剪切对损伤的不同响应。用有限元法数值模拟了如下现象,一旦基体出现临界损伤,弯曲载荷则从最大值急速下降,同时基体的临界损伤区很快扩展,并且发生局部纤维断裂,从而使复合材料层板几乎失去了承弯能力,整体呈脆性特性。为便于了解破坏过程,给出了若干状态时板内的应力等值线分布图。

NUMERICAL SIMULATION OF BENDING RUPTURE FOR COMPOSITE LAMINATED PLATE WITH BRITTLE MATRIX

In this paper the bending rupture of a composited laminated plate is investi-gated. The fiber layer is assumed to be orthotropic elasticity and the matrix is brittle damage material. A damage model for brittle materials subjected to arbitrary stress is developed. Al-though this is an isotropic continuum damage model,by using the difinition of the equivalent damage strain, the different damage responses from tensile , compressive and shear loading can be distinguished. Using FEM these phenomena are simulated numerically. Along with the occurrence of a matrix critical damage,the bending load decresed rapidly from maximal one, soon afterwards a critical damage rigion in the matrix expanded and a patch of fiber breaked, then the compostite plate almost lose its bearing capacity and behave a character of fully brit-tle rupture. For discovery of the rupture process some stress distributions of this process are pictured.