利用惯量椭圆进行岩石有限应变分析

提出了利用惯量椭圆对任意形状矿物颗粒进行描述的方法，并利用惯量椭圆理论，计算了岩石薄片中任意形状矿物颗粒的惯量椭圆，通过颗粒面积对椭圆参数进行标准化，得到每一矿物颗粒的等效应变椭圆。等效应变椭圆能够有效地反映对应矿物颗粒的优选方位以及变形特征，进而利用椭圆的矩阵参数形式对等效应变椭圆进行统计分析，获得岩石的有限应变椭圆；同时给出了相应的数值计算方法，编制了软件Straindesk，并得到了成功的应用。该方法克服了先前应变测量中的局限性，方便实现计算机的自动分析，具有较强的有效性和广泛的适用性。

Finite Strain Measurement of Rocks by Using of Inertia Moment Ellipses

Finite strain analysis is an important technique of the modern structural geology. This paper presented one new method to describe the arbitrary grains by using the inertia moment ellipses. Based on the theory of inertia moment ellipsoid, the inertia moment ellipses of the arbitrary mineral grains in the rock slice were calculated. Because of the invariable area of the grains, the parameters of these ellipses were normalized. Then the equivalent ellipses corresponding to the moment ellipses were obtained. The equivalent ellipses reflect the preferred orientations and the deformation features. While the finite strain of the deformed rock was gained by the statistical analysis on the equivalent ellipses present in the parameters form of matrix. This new method is very effective and applicabile, especially when the amount of the grains is not sufficient or the distribution is not well proportioned. The analysis process is very convenient by using the computers programs.