Investigation the effect of mechanical properties of materials in solving the inverse identification problem by means of optimization algorithms

Determining the internal structure of objects such as identification of impurities, estimation of mechanical properties and identification of internal boundaries and cavities is one of the important issues in industries. Objective of the present article is to investigate the effect of the mechanical properties and the effect of the location of the interfacial boundary in solving the inverse problem of identifying the internal boundaries of a Non- homogeneous body, consisting of two homogeneous bodies, along with the estimation of the modulus of elasticity and Poisson's ratio of its components. The solution has been done using the combination of the numerical method of boundary elements method along with the optimization method of the Imperialist Competitive Algorithm (ICA) and the simplex method. The obtained results, show the effectiveness of the ICA optimization and the simplex method in estimating the mechanical properties and identifying the interfacial boundary configurations. But, as the boundary approaches the lower part of the material and the mechanical properties approach, the boundary estimation error increases to 8.65% for the solved examples, which again indicate the strength of this method to estimate the boundary. Also, in the investigation of the effect of unavoidable errors in the measurement of displacements, with the increase in the error percentage, the convergence to the real boundary is reduced, so that for error greater than 5%, the geometry of the internal boundaries converges to unrealistic boundaries and the calculations are no longer valid.