COEFFICIENT CALCULATION DEVICE, COEFFICIENT CALCULATION METHOD, AND COEFFICIENT CALCULATION PROGRAM OF CONSTRUCTIVE EQUATION OF SUPERELASTIC MATERIAL

摘要

PPROBLEM TO BE SOLVED: To provide a device and method which calculates a coefficient of an equation of a Mooney-Rivlin model, which meets a stable condition required for more stable stress simulation. PSOLUTION: The coefficient calculation device which estimates a value of a coefficient included in the Mooney-Rivlin model being one of strain energy density functions for use in a constitutive equation of a superelastic material, from a measurement value of material test and a coefficient calculation formula, includes: a storage part 3 for storing the measurement value and data of calculation process; and a calculator 2 connected to the storage device 3. The calculator 2 includes: a coefficient calculation means 22 for calculating an approximate solution of the coefficient by a constrained nonlinear least square method; an error evaluating/solution updating means 23 for evaluating errors of the approximate solution to update a candidate optimal solution; a convergence evaluating means 24 for evaluating a convergence state in repeated calculation of the approximate solution; and an initial change means 25 for, in the case of difficulty in convergence, taking the candidate optimal solution as an initial value of the coefficient and initializing a parameter of the constrained nonlinear least square method to restart the constrained nonlinear least square method. PCOPYRIGHT: (C)2009,JPO&INPIT