Experimental Estimation of Thermomechanical Properties and Thermal Boundary Conditions

This paper considers a study of thermomechanical coupling. Through a study in a 1D configuration, a thermomechanical transfer function using analytical technique was performed. This function links the mechanical deformation and the temperature. The goal of this research is to propose an inverse thermoelastic approach for determining this excitation temperature and the thermomechanical properties of materiel from experimental measurements. In the first phase, we made a computational study to evaluate the efficiency of our technique by investigating the sensitivity to thermoelastic parameters as well as the influence of measurement noise on all experimental measurements. The use of the Tikhonov regularization technique and truncated singular value decomposition (TSVD) is demonstrated to effectively apply the inversion using noised measurements. Temperature and deformation measurements are used to estimate the coefficient of thermal expansion (CTE) and thermal diffusivity by minimizing an objective function using a least squares criterion. Experimentally, a strain gauge is used to measure this deformation and then apply a deconvolution product to those measurements to determine the temperature of the heated surface. As a result, it is no longer necessary to know the temperature distribution to solve the thermomechanical problem. To identify the two-thermoelastic properties, both temperature measurement mechanical deformation are used in the same experimental bench.