Experimental validation of workpiece deformation simulations by means of rigorous boundary condition analysis

Abstract

The new concept of process signatures allows the targeted adjustment of workpiece surface integrity in various manufacturing processes. Since the process signature is often identified by means of numerical simulations, its experimental validation is an important research aspect. While the mechanical workpiece load required to determine the process signature can be measured in the process using speckle photography, the boundary conditions assumed for the simulation usually do not match with the experiment. The reason for this is, for example, the uncontrollable thermal drift movements of the workpiece in the clamping. Using the example of a laser hardening process, a method for reducing clamping influences is proposed. The force-free single-point fixture of the workpiece, which is used in this context, ensures defined process conditions in the center of the measuring field and, with its fixed point, simultaneously specifies the boundary conditions for the simulation. As a result, consistent agreement between measurement and simulation is achieved with deviations of less than one percent and validation of the process simulation is enabled.