The structure of rock is extremely complicated discontinuous and heterogeneous body, its mechanics property has non-linear, anisotropism and rheology characteristic, which changed over time.
岩石的结构是极其复杂的非连续和非均质体，其力学属性具有非线性、各向异性及随时间变化的流变特性。
2
Based on the principle of a varied mass system, the nonlinear mathematical model of the crop mechanics for an axial threshing process was set up.
运用变质量系统的基本原理，建立轴流脱粒过程中谷物运动的非线性动力学模型。
3
The result show that the model in this paper suits the mechanics characteristic of the pavement better, and has high theory value in non-linear pavement analysis.