DDHADTENS: A program for extracting anisotropic damage variables from tensors using harmonic analysis
Description
The present DDHADTENS program is provided to extract variables characterizing anisotropic damage of elastic tensors. The theory is based on harmonic analysis. The program takes as input: (a) an undamaged elastic tensor and (b) a series of damaged elastic tensors. The output is a series of damage variables, defined as the coefficients of the spherical harmonics describing scalar damage orientation functions, which can be interpreted as the damage of elastic coefficients varying with the direction. These tensors can be obtained externally by numerical fracture simulations in a Representative Volume Element. A 2D version of the code is first provided. In this case, the elastic tensor is given by a 3 x 3 matrix and 6 damage variables are obtained. Second, a 3D version of the code is proposed, where the elastic tensor is given by a 6 x 6 matrix and 21 damage variables are obtained. In both case, a set of reduced variables using PCA is also provided. Numerical examples associated with degradation of elastic properties of Representative Volume Elements (RVE) are described.