STRESS WAVE METHOD FOR IDENTIFICATION OF VISCOELASTIC MATERIAL PROPERTY BASED ON FINITE-ELEMENT INVERSE-ANALYSIS

This paper proposes a procedure to identify the viscoelastic material constants using the inverse analysis and the finite element analysis. The procedure requires two measured data: the applied impact-force and the structural elastic response at a point, and further assumes the material viscoelasticity following the Prony series expansion. In this procedure, we infer the viscoelastic material constants in the following steps: we initialize the viscoelastic material constants, and then calculate the stress state at the point, and finally, we check the equilibrium of the constitute equation. The procedure is repeated until the equilibrium of the constitute equation is satisfied. In this repetition, the viscoelastic material constants are updated following the Gauss-Newton method. In addition, we evaluated the method by using data obtained from a simulated impact on a viscoelastic plate, and the results were rather promising. Finally, we studied the convergence of the procedure using various random material constants as the input data.