Recent Developments in Inverse Problems - Abstract

Lahmer, Tom

Identification of residual stresses by coupled thermal -- mechanical analysis

T. Lahmer, J. Hildebrand, S. Bock, K. Gürlebeck ĭentification of Residual Stresses in Steel under Uncertain Model Components We discuss the inverse and ill-posed problem of identifying residual stresses in steel structures. Therefore, steel specimen are subjected to thermal loadings. Due to these loadings deformations occure which are recorded by high resolution laser scanners. The latter serve as input for the inverse problem, where residual stresses are to be recovered.
As the inverse problem is ill-posed, it requires regularization, where iteratively regularizing methods are applied together with a posteriori stopping criteria.
The quality of the identified stress fields depends on a list of parameters, e.g., the choice of the regularization parameters, the assumed noise in the measurements, and further uncertainties in other model parameters, like the thermal expansion coefficient and so on. Sources of uncertainties in the identified parameters will be assessed. Results of this assessment may motivate for possible adaptions of the experimental setup.