Computer aided generation of anisotropic constitutive expressions (Q1088432)

A procedure for determining the form of polynomial constitutive expressions which describe the response of anisotropic materials is discussed. The procedure employed is such that the essential algebraic computations required may be automatically carried out by a computer program which requires only the order and symmetry of the tensors t, \(e_ 1\), \(e_ 2,..\). appearing in the polynomial constitutive expression \(t=f(e_ 1,e_ 2,...)\), the degrees to which \(e_ 1,e_ 2..\). appear in this expression and the group \(\Gamma\) under which the expression is to be invariant. A Fortran program has been developed which covers all of the 32 crystal classes. The program currently considers only cases where the tensors \(e_ 1,e_ 2,..\). are first or second- order tensors but could be readily augmented to consider cases where some of the \(e_ i\) are higher-order tensors.