Accuracy of material parameter estimation

Abstract: This thesis deals with material parameter estimation for non-linear material models, which is an extremely important part of a finite element analysis. The aim of this work is to both estimate parameters and to quantify the their accuracy. The latter enable a total assessment of how the accuracy at different stages in i.e. the life prediction process affects the final estimated life. Thereby it is also possible to estimate the cost and value of improvements in material data in the different stages of the calculation. The thesis comprises an introductory part and two appended papers. The first paper discusses the influence on parameters and estimated life dependent on the choice of cost-function in the optimisation process. In the second a method for stress integration with regard to transverse recovery is discussed.