摘要
Norton方程通常用于反映金属类材料的稳态蠕变阶段,为了研究Norton方程在岩石材料蠕变损伤的适用性,通过单轴蠕变压缩试验,对同一批试件施加不同轴向应力,绘制不同应力下的时间-蠕变曲线,随着轴向应力的增加岩石出现衰减、稳态及加速蠕变三个阶段。根据Norton提出的经验公式和七点法计算出岩石的应力指数,结合损伤力学理论与Norton提出稳定蠕变和加速蠕变的指数关系,计算出不同时间点的损伤变量,从而绘制出岩石的时间损伤曲线。采用前人提出的损伤模型绘制理论曲线和实验曲线对比,结果表明该曲线符合岩石随时间流变的损伤演化规律,从而得出岩石加速蠕变阶段的损伤曲线符合Norton方程。
The Norton equation is usually used to describe the secondary creep of metal. In order to verify whether the Norton equation is suitable for the application of rock material creep damage, uniaxial compressive creep tests were performed to obtain creep curves of rock samples under different stress levels. The creep curves exhibited typical three-stage curve including primary creep, secondary creep and tertiary creep. The empirical formula proposed by Hollomon and seven-point methods were adopted to calculate the stress index of rock. Combining damage mechanics theory and the relationship between secondary creep and tertiary creep, the damage curves of rock at different time were derived. According to the damage model proposed by other researchers, the theoretical curves and test curves are compared and the results show that the curve is consistent with the characteristics of rock damage evolution with time. It is concluded that the damage curve of the rock accelerating creep phase follows the Norton equation.
出处
《水利与建筑工程学报》
2017年第2期37-42,共6页
Journal of Water Resources and Architectural Engineering
基金
国家自然科学基金项目(41672301
41172265
51474051)
中央高校基本科研业务费项目(N150102002)
关键词
稳态蠕变
加速蠕变
损伤
应力指数
时间因子
steady state creep
accelerated creep
damage
stress index
time factor
