高温下岩石损伤本构模型研究

发布时间：2018-03-17 22:10

  本文选题：岩石　切入点：温度　出处：《广西大学学报(自然科学版)》2017年01期 　论文类型：期刊论文

【摘要】：利用连续损伤理论和统计强度理论,根据岩石微元强度服从Weibull随机分布的特点,定义了弹性模量为岩石热损伤变量,推导了岩石的热损伤演化方程,引入岩石应力—应变曲线特征参量,同时考虑了岩石全过程应力—应变曲线的峰值条件和几何条件,建立了温度效应下岩石的损伤统计本构方程,并通过试验进行验证。试验结果表明:随着轴向应变的增加,岩石损伤经历演化、稳定扩展、损伤加速,直至破坏四个阶段;随着温度的增加,岩石的初始热损伤不断加剧,600℃是花岗岩热损伤的阀值点;损伤本构理论曲线与试验曲线较吻合,所建立的本构模型在岩石峰值前后的拟合明显高于传统方法,但也存在一定的偏差,可能由于在方程建立及参数的确定过程中,进行的假设和忽略对方程的精度产生了影响,本文的研究对建立高温三轴状态下的岩石损伤本构模型具有一定的参考价值。
[Abstract]:Based on the continuous damage theory and statistical strength theory, according to the characteristics of Weibull random distribution of rock microelement strength, the elastic modulus is defined as the rock thermal damage variable, and the thermal damage evolution equation of rock is derived. The characteristic parameters of stress-strain curve of rock are introduced, and the peak and geometric conditions of stress-strain curve of rock are considered, and the statistical constitutive equation of rock damage under temperature effect is established. The experimental results show that with the increase of axial strain, the rock damage evolves, expands steadily, accelerates the damage, and increases with the increase of temperature. The initial thermal damage of rock is increasing at 600 鈩，

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