沿两条内部平行裂纹受压时材料的断裂问题

顺着平面内的平行裂纹受压材料的断裂问题并不能在线性断裂力学的框架内进行描述，Grif-fith－Irvin型或COC型的断裂判据，虽然可以用来处理经典的线性断裂力学，但对本题则完全不适用，这是因为这些压力对应力强度系数没有影响，与裂缝孔隙值也没有关系1，2]，这一类问题只能采用新的方法，本文的第一作者曾建议过一种新方法，在这一方法中仍然使用了线性关系，但这种线性关系是从变形固体力学中的非线性方程导出的3，4，5]．这里必须指出，这种方法曾在变形体稳定性问题中广泛地采用过。作为断裂开始的判据，我们采用了裂缝缺陷附近的局部失稳的判据，在这类情况下，我们认为是从失稳过程引发断裂过程的。

On Problems of Fracture of Materials in Compression along Two Internal Parallel Cracks

The fracture of materials under the action of compressive. forces, directed along cracks which are parallel in plane cannot be described within the framework of the linear fracture mechanics. The criteria of fracture of the Griffith-Irvin or COC type , used in classical linear fracture mechanics, are not applicable in this problem, since these forces have no influence on stress intensity coefficients and on values of or acks opening1,2].The problems of such a class may be described only by using new approaches.One of possible approaches is presented by the first author, which involves using linearized relations, derived from exact non-linear equations of deformable solid body mechanics3,4,5]. It should be remarked here that this approach has been widely used in problems of deformable bodies stability.As a criterion of the initiation of fracture the criterion of local instability near defects of the crack type is used. In these cases the process of loss of stability initiates the fracture process.