Determination of Constitutive Parameters in Inverse Problem Using Thermoelastic Data

摘要

A new inverse problem formulation for identification of constitutive parameters in orthotropic materials from load-induced thermal information is developed using Levenberg-Marquardt Algorithm and Airy stress function. Inverse methods were used to determine the constitutive properties as well as the thermoelastic calibration factors of a loaded perforated graphite/epoxy laminated composite by processing noisy simulated thermoelastic data with an Airy stress function in complex variables. Equilibrium, compatibility, and traction-free condition on the boundary of the circular hole are satisfied using complex-variable formulation, conformal mapping and analytic continuation. The primary advantage of this new formulation is the direct use of load-induced thermal data to determine the constitutive parameters, separate the stresses, i.e., evaluate the individual stress components, including on the edge of the hole, and smooth the measured data, all from a single test. The inverse method algorithm determined the constitutive properties with errors less than 10%.