Estimation of Mechanical Properties in Non-homogeneous Body Using Surface Displacement Measurements

The purpose of this present research is to estimate simultaneously the mechanical properties i.e. Young s modulus and Poisson s ratios of the components of two connected domains using a discrete number of displacement measurements obtained by a simple tension test. A unique combination of a global optimization method i.e. the Imperialist Competitive Algorithm (ICA) along with the inverse application of the Boundary Elements Method (BEM) is employed in an inverse software package. A fitness function, which is the summation of squared differences between calculated displacements and measured displacements at identical locations on the outer boundary, is minimized. Due to the complexity and the ill-posed nature of this identification problem, ICA is used to find the best guesses of the unknown mechanical properties of the components of an inhomogeneous body. Several examples are selected and the accuracy of the obtained results is discussed. The effect of experimental measurement errors and the influence of material properties of the sub regions on the identification process are also investigated.