It has been find that there is no the second stage of creep when material under the condition of higher stress. Then judgment criterion has been proposed to deal with that phenomenon.

针对金属材料在较高应力下没有蠕变稳定阶段的现象，提出了金属材料高低应力值的判定准则并根据高低应力的不同特点推导了不同的耦合损伤本构模型。

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The experimental result shows that the lateral stress threshold of the second creep stage is less than that of axial stress threshold.

试验结果表明，横向稳定蠕变阶段的应力阈值低于轴向稳定蠕变阶段的应力阈值；

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The new equation correctly reflects such a fact as that the creep damage starts or appears at the end of the second stage and results in the accelerating creep and failure.

造成软岩蠕变加速阶段出现的原因是损伤起始于或明显显现于蠕变第二阶段之末。

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