根据矩张量理论构建了细观尺度上巴西劈裂试验声发射的细观模拟方法。通过试验和计算结果的对比分析,验证了该方法的合理性。该方法可同时给出声发射事件发生的时间、空间、破裂强度等特征,再现试样破裂空间演化规律。研究发现:在达到峰值抗拉强度之前,声发射事件比率和破裂强度较低;在峰值和残余抗拉强度之间,声发射事件比率和破裂强度均较高。声发射事件比率随破裂强度变化近似呈极值分布;在均值至最大破裂强度之间,声发射事件累积比率随破裂强度的降低近似呈指数函数增加。每次声发射事件所包含的微破裂数,随破裂强度的提高而增加,近似呈指数函数关系;声发射事件比率与微破裂数近似呈负指数函数关系。
Based on the moment tensor theory, a mesoscopic simulation method was proposed for acoustic emissions ( AE) during Brazilian test in mesoscale. Its rationality was proved by comparative analysis between experimental and calculative results. This meth-od can simultaneously provide the occurrence characteristics of AE events such as time, location and magnitude, and reproduce the spatial evolution law of fracture. It is found that before the peak tensile strength, the ratio and magnitude of AE events are lower, but from the peak tensile strength to residual tensile strength, the ratio and magnitude of AE events are higher. The ratio of AE events shows an extreme distribution with the variation of magnitude. Between the mean and peak value of magnitude, the cumulative ratio of AE events increases in an exponential function with the decrease of magnitude. The number of microcracks in each single AE event similarly increases in an exponential function with the increase of magnitude, but the ratio of AE events exhibits a negative exponential function relationship with the number of microcracks.