雁型断裂的分形模型和能量耗散

A Fractal Nodel and Energy DissiPation for En Echelon Fractures

现场和实验室观察表明，在断裂区内的雁型裂纹具有一个Ｒｉｅｄｅｌ几何结构。本文应用剪切裂纹位错堆积（Ｐｉｌｅ－ｕｐ）模型，描述了雁型裂纹形成的拉破坏机理，建立了雁型裂纹的分形模型来模拟Ｒｉｅｄｅｌ几何结构。根据这个模型，可以直接量测出现场和实验中出现的雁型裂纹的分形维数。在此基础上，应用分形损伤演化模型，推导出了雁型裂纹的能量耗散，进而解释了雁型裂纹形成过程的分形本质。

Field and laboratory obervations showed that en echelon fractures within fracture zones havea Riedel within Riedel structure. The tensile failure mechanism of formation of en echelon fractures can be described by the pile-upe of shear crack-dislocations . A fractal model can be used to simulate the Riedel Within Riedel geometry , allowing the direct measurement of the fractal dimensions of en echelonfracture systems. The energy dissipation of the en echelon fracture system can be deduced by using afractal damage evolution model which explains the evolution process of en echelon fracture systems.The fractal nature of the fractures can be used to derive an accurate estimation of total energy dissipa-tion.