材料动态断裂碎片特性的理论描述

考虑裂纹间相互卸载作用，引入最小尺寸碎片概念。同时，假设断裂成核点随机分布于样品中，依据统计原理导出了一组完备的方程组，由此从理论上给出了碎片的数目及其大小分布关系式。与金属圆柱形壳体和圆环的膨胀破坏实验结果比较表明，该方程组对实验结果具有很好的预测能力。

THEORETICAL DESCRIPTION FOR THE CHARACTERISTICS OF FRAGMENTATION OF MATERIALS IN DYNAMIC FRACTURE

In this paper,a theory for predicting fragment number and size distribtution is proposed.Considering the unloading effects among fracture nucleation,we introduce a concept of minimal fragment size.With the assumption that the sites of fracture nucleation are randomly distributed in the sample,we deduce out a set of enclosed equations for predicting the fragment number and size distribution.Comparison with the expanding cylindrical shell and ring experiments is made,results show that the theory is helpful for prediction of fragments.