C06: Surface-based optical measurements of mechanical material stresses

In the first phase of the SFB, the suitability of speckle photography for in-process measurements in highly dynamic manufacturing processes was demonstrated. Specially adapted evaluation algorithms and measuring systems were developed for this purpose, so that the use of speckle photography could also be realized on fast-rotating systems such as single-tooth peripheral milling, grinding under strong flying sparks, deep rolling or laser hardening.

Three-dimensional deformations of the measured surface cannot be measured yet. This problem is to be solved by a novel approach for in-process measurements based on an analysis of the shape-modified speckle correlation functions. In addition to this three-dimensional reconstruction of the deformation fields, a central aim of the project is to determine parameters for establishing process signatures from the time-resolved stress fields measured in highly dynamic manufacturing processes. In this connection a quantification of the measurement uncertainty budget and a reduction of measurement uncertainty contributions are investigated. In addition, data analysis is to be accelerated, for example by parallelization approaches. This reduces long evaluation times and enables in-process control in the future.

Funding authority:DFG - German Research Foundation
Funding ID:SFB TRR 136