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为研究岩石等脆性材料的损伤对裂纹动态扩展的影响,采用动态透射焦散线方法,模拟脆性材料裂纹与损伤相互作用的动态过程,进行多种损伤情况下有机玻璃试样裂纹动态扩展过程试验研究,讨论不同类型损伤对脆性材料裂纹动态扩展规律的影响和裂纹与损伤相互作用的机制。试验结果表明:不同类型的损伤对裂纹扩展影响不同,除裂纹型损伤外,其他几种类型损伤的存在均会引起裂纹扩展出现短暂停滞,停滞时间与损伤的尺寸及距离扩展裂纹路径的距离有关系;裂纹扩展路径上存在单个圆孔时会影响裂纹扩展速度,裂纹消耗能量增大;而多个圆孔情况下,材料局部弱化,裂纹扩展速度增大,而裂纹扩展消耗能量降低;表面损伤和局部贯通裂纹的尺寸、相对裂纹扩展路径距离等影响裂纹扩展速度,但能量消耗并未增大;对称裂纹相互竞争,同步扩展,裂纹尖端位置或裂纹长度的微小差别(例如裂纹长度相差3.68%)就会对裂纹起裂产生明显影响,导致2个裂纹起裂时间不同,裂纹扩展以后,先起裂的裂纹尖端应力强度因子大说明能量集中到相应裂纹尖端,从而越有利于该裂纹的扩展,扩展速度也就越大(相差约38.9%),相同条件下裂纹扩展所消耗的能量也越大。
In order to study the influence of rock and other brittle materials on the dynamic propagation of cracks, a dynamic transmission caustic method was used to simulate the dynamic process of the interaction between cracks and damage of brittle materials. The dynamic crack propagation process of plexiglass specimens under various damage conditions The effects of different types of damage on the dynamic propagation of cracks in brittle materials and the mechanism of the interaction between cracks and damage are studied and discussed. The experimental results show that different types of damage have different effects on crack propagation. Except crack-type damage, the existence of several other types of damage can cause a brief stagnation of crack growth. The size of the dead time and damage and the distance from the crack propagation path are . The existence of a single circular hole in the crack propagation path will affect the crack propagation rate and increase the energy consumption of the crack. In the case of multiple circular holes, the material locally weakens, the crack propagation rate increases, and the energy consumption of crack propagation decreases. The surface damage And the crack size of the local crack, the relative crack propagation path distance affect the crack propagation speed, but the energy consumption does not increase; symmetric crack compete with each other, synchronous expansion, crack tip position or crack length slightly different (for example, the crack length difference of 3.68% ) Will have a significant effect on the initiation of cracks, resulting in different initiation times of the two cracks. After the cracks are cracked, the large stress intensity factor at the crack tip indicates that the energy is concentrated at the corresponding crack tip, which is more advantageous to the crack growth , The greater the speed of expansion (a difference of about 38.9%), the same conditions, the greater the energy consumption of crack expansion