Non-contact gauging of surface stresses including residual stresses for large and smallest objects

At the University of Applied Sciences, Esslingen a software was developed by combining a professional FEM package with the ESPI. This software uses the advantages of both powerful methods and merges them into a new process, to determine non-contact, surface based, two-dimensional stresses. Based on the deformation gauging by the speckle interferometer, strains, stresses and residual stresses of any object can be determined. They can be visualised almost in real time by the FEM postprocessor [1]. The software's mode of operation is explained using a punched automotive body sheet iron and an inclination sensor from micro system technology.