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准脆性材料损伤斑图的生长过程研究,对于认识重大工程动力学灾变孕育、发生的机制具有特别重要的基础性意义。尤其是岩石类动力学灾害如地震、岩爆、煤矿开采中的三突,其形成机制都可归结为岩石损伤演化诱致结构灾变的模式。损伤斑图的生长过程可以再现灾变的孕育、发生过程,具有非常深刻的物理力学背景。该文根据微损伤不可逆演化原理,利用格形有限元模型,模拟二维平板在自适应位移加载条件下,从点状微损伤斑图到宏观贯通断裂的不可逆的分形生长过程。其中的微损伤机制全部采用拉应变准则,数值程序是在ANSYS平台上开发。结论表明,形态复杂的斑图可由细观单元简单的动力学规则和单元间的相互耦合演绎形成,斑图边界呈分形向外移动。最后,对斑图生长过程对工程灾变预测的启示作了初步讨论。
The study on the growth process of the quasi-brittle material damage map has a very important and basic significance for understanding the mechanism of the major engineering dynamics catastrophe. In particular, the formation of rock-like dynamic disasters such as earthquakes, rockbursts and coal mines can all be attributed to the model of structural damage induced by rock damage evolution. The growth process of the damaged plaque can reproduce the occurrence and development of catastrophe and has a very profound background in physical mechanics. According to the principle of irreversible evolution of micro-damage, a finite element model of lattice was used to simulate the irreversible fractal growth process of two-dimensional slab from point-like micro-damage spots to macro-through fracture under adaptive displacement loading conditions. One of the micro-damage mechanisms used to pull the strain criterion, the numerical program is developed on the ANSYS platform. The results show that the morphologically complex motifs can be formed by the simple kinetic rules of mesoscopic cells and the interdependent coupling deduction of the cells, and the boundaries of the motifs move outward with fractal. Finally, the enlightenment of speckle growth process on prediction of engineering catastrophe was discussed.