SENSITIVITY ANALYSIS AND PARAMETER ESTIMATION OF HEAT

SEBASTIÁN PEREYRA; GUILLERMO LOMBERA; GLORIA FRONTINI; SANTIAGO URQUIZA

João Pessoa, Brazil

Simposio; Inverse Problems, Design and Optimization Symposium; 2010

Federal University of Paraiba, UFPB

Although numerical models of heat transfer and material flow has contributed to understand the friction stir welding (FSW), there are certain input model parameters that can not be easily determined either from fundamental principles or from the welding conditions. Thus, the model predictions do not always agree with experimental results. In this work, sensitivity analysis and parameter estimation approach were performed to test heat transfer and material flow models. A forward-difference approximation to compute the sensitivity of the solution with respect to the unknown parameters and the Levenberg- Marquardt (LM) method for nonlinear estimation of parameters were used. The numerical models were developed by the finite element method (FEM). The unknown parameters were: the friction coefficient and the amount of material stuck to the tool surface, the heat transfer coefficient at the bottom surface and the internal heat generation. It was determined the way in witch the parameters independently affect the results and the importance of the location of reference points that take part in the objective function.