Material parameter identification for orthotropic composite structure by the finite element method

Based on the computing platform of the finite element method commercial software ABAQUS，a parameter identification method was developed for orthotropic composite structures. The material parameter identification problem was formulated as the problem of minimizing the objective function defined as a square sum of differences between the measured and calculated data on displacements. Levenberg-Marquardt method，in which the sensitivity analysis was based on the differentiation of the discretized algebraic finite element matrix equations with respect to material parameter，was used to solve the minimization problem. Numerical example shows that the proposed method for parameter identification is feasible and effective. The initial values and upper and lower bounds of parameters identified play an important role in the parameter identification process. Therefore，a priori information of parameters should be used as much as possible. ABAQUS is effective and reliable commercial software for the finite element method，and hence the proposed method based on such a kind of software has strong practicability.