岩石塑性应变梯度与Ⅱ类岩石变形行为研究

The study of plastic strain gradient and class Ⅱ behavior of rock

提出了岩石塑性变形的应变梯度理论,并采用该理论解释了岩石力学界长期争论的关于Ⅱ类岩石变形行为是否存在的问题。文中证明Ⅱ类岩石变形行为是有条件存在的,只要岩石试件的长度L,弹性模量E,峰值后降模量λ及岩石内部长度l 满 足1 - 2 π(1 + Eλ) lE > 0 ,就会出现Ⅱ类变形行为。

In this paper the theory of plastic strain gradient has been put forward and thereby the problem is discussed on whether the deformational behaviour of the rock of class Ⅱ is exist. It has been proved that the existence of the deformational behaviour for the rock of class Ⅱ is conditional, that is , when 1-2 π EλlL>0 the behaviour manifests itself. The influence of the height of rock specimen, the descending modulus λ of rock and the internal length l on the class Ⅱ behavior has been discussed.