Computerized distortion minimization of laser beam welded complex components

• Applicant: Professor Dr.-Ing. Michael Friedrich Zäh
• Subject Area: Production Automation and Assembly Technology
• Term: from 2016 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 319905670

Laser beam welding is a fast and flexible joining process. Despite the low energy deposition, laser beam welding leads to component distortions and, thus, to non-compliance with dimensional tolerances. Therefore, additional processing steps like thermal or mechanical straightening are required. Simulation based investigations within numerous research works have contributed to a better understanding of distortions and to an enhanced prediction of component distortions of simple geometries. For complex geometries, however, the numerical detection of appropriate process parameters for minimal component distortion leads to rising costs due to increasing computational expenses. Moreover, the task to build the numerical model contains many non-automated processing steps and requires a lot of user expertise. The size of these complex geometry models therefore requires a new approach for the distortion computation and minimization within a reasonable time.Hence, the aim of the proposal is the development and validation of a new computerized and efficient method for the prediction of appropriate process parameters for laser beam welded complex geometries with minimal component distortion. An additional goal of this proposal is the demonstration of a possible way to automate the single modelling steps and to simplify user control of the procedureIn order to predict the appropriate process parameters based on numerical methods, a complex geometry has to be divided into subareas -- similar to the so called local-global-method, but with different joining operations. Subsequently, with regard to the residual stresses and the component distortion, these subareas have to be numerically analyzed. The computed distortions of the subareas can then be applied to compute the distortion of the whole complex geometry. The application of this method in combination with the use of optimization algorithms will facilitate the prediction of appropriate process parameters for minimal component distortion in welded geometries.

• DFG Programme: Research Grants