关键词: 有限元方法, 流变参数, 数值模拟

Abstract:

Rocks show rheological properties under high temperature and high pressure.Rheological parameter is an important parameter for numerical simulation of the dynamic process of the earth.The rheological parameters can be obtained by means of the high temperature and high pressure creep experiments in the laboratory and by the inversion of the field geophysical data.There have been some high temperature and high pressure experiments on single minerals.However, it is difficult to carry out multi-mineral experiments.In this study, we discuss the possibility of using the finite element method to calculate the rheological parameters of multi-mineral rocks under the condition that the rheological parameters of minerals are known.The results show that the calculated results match the parameters obtained in the high temperature and high pressure experiments.The results show that the rock as a whole will show anisotropy if the mineral arrangement has the advantage of direction (such as the existence of the granitic mylonite foliation), even though mineral mechanical properties are approximatly isotropic.When loading force is perpendicular or parallel to mineral foliation, equivalent viscous coefficient of rock is larger; and when the angle is 30 degrees, equivalent viscous coefficient is minimized.

Key words: finite element method, rheological parameter, numerical simulation