论文部分内容阅读
为考察温度和加载速率对花岗岩断裂特性的影响规律,对25~800℃之间5种温度水平高温后的中心直裂纹花岗岩巴西圆盘试样分别进行了5种加载速率下的室内劈裂试验.结果表明:圆盘的荷载-位移曲线呈现典型的脆性特征,但随温度的升高,脆性特征逐渐弱化,与加载速率相比,温度对曲线的发展趋势影响较大;随温度的升高,花岗岩断裂韧度逐渐减小且在400℃时发生突变;不同温度条件下断裂韧度随加载速率的增大逐渐增加,但增加幅度逐渐减小最终趋于平缓,具有明显的加载速率效应,提出了相应的经验公式KIC=A+B/(v+C),其中随温度的升高,参数A逐渐降低,参数B波动较小,而参数C逐渐增大,同时获得了花岗岩材料断裂韧度的下限值KIC0.
In order to investigate the influence of temperature and loading rate on the fracture characteristics of granite, indoor cleavage tests were carried out at five loading rates on central-cracked Brazilian granite samples with different temperatures at 25 ~ 800 ℃. The results show that the load-displacement curve of the disk presents a typical brittle characteristic, but the brittle characteristics gradually weaken with the increase of the temperature, and the temperature has a greater influence on the trend of the curve than the loading rate. With the increase of the temperature , The fracture toughness of granite gradually decreases and it changes abruptly at 400 ℃. The fracture toughness of granite increases with the increase of loading rate under different temperature conditions, but the increasing amplitude decreases gradually and finally tends to be gentle with obvious loading rate effect. The corresponding empirical formula KIC = A + B / (v + C) is proposed. With the increase of temperature, the parameter A gradually decreases, the parameter B fluctuates less and the parameter C increases gradually. At the same time, the fracture toughness The lower limit of KIC0.