含冰甲烷水合物的应力与应变关系

对含冰甲烷水合物试样进行了三轴压缩试验，分析了与其应力、应变行为相关的起始屈服应变、起始屈服强度和起始屈服模量随围压和温度变化的关系；并利用Duncan-Chang双曲线模型获得含冰水合物的初始变形模量、极限偏主应力和破坏比，分析了它们与围压和温度的关系。结果表明，起始屈服应变、起始屈服强度、初始变形模量和极限偏主应力均随围压的增加和温度的降低而增加；起始屈服模量仅受温度影响；破坏比随围压的升高有降低的趋势，而随温度降低有增加的趋势；实验数据拟合结果表明，起始屈服应变、起始屈服强度和极限偏主应力分别与温度和围压呈线性关系，初始变形模量与温度和围压呈幂函数关系。

A study on stress-strain relations of methane hydrates

Based on the result of triaxial compressive tests on methane hydrate samples,we investigated relationships of related stress-strain behaviors including the initial yield strain,initial yield strength and initial yield modulus with the change of confining pressures and temperatures.The initial deformation modulus,ultimate deviator stress and damage ratio of methane hydrates were calculated using the Duncan-Chang hyperbolic model,and the relationship of them with confining pressures and temperatures was analyzed as well.The results showed that all the initial yield strain,initial yield strength,initial deformation modulus and ultimate deviator stress increased with the increase of confining pressures or the decrease of temperatures.The initial yield modulus was only affected by temperatures.The damage ratio showed a trend to decrease with the increase of confining pressures,but increase somewhat with the decrease of temperatures.By fitting the experimental data,it was found that the initial yield strain,initial yield strength and ultimate deviator stress had a linear relationship with confining pressures and temperatures,respectively,while the initial deformation modulus showed a power function curvilinear relationship with confining pressures and temperatures.