Identification Problems for Isotropic Viscoelastic Materials with Long Nonlinear Memory

Abstract

This paper is concerned with the identification problems of unknown parameters in viscoelastic materials with long nonlinear memory. The unknown parameters are diffusion constants and kernels in nonlinear memory terms, and the identification of such parameters is studied by means of quadratic optimal control theory due to Lions [10]. The existence of optimal parameters is proved, and the necessary condition is established for distributive and terminal values observation by using the transposition method.