FEA Approach for Wear and Damage Prediction of Tools for the Progressive Die Stamping of Steel Washers

Abstract

In progressive die stamping processes, maintenance activities caused by tool damage, and wear represent economic losses for companies. An effective predictive maintenance strategy can only be implemented if maintenance data coming from the operations are correlated to specific process-related information. As a part of a more general data-based predictive maintenance strategy, the main causes of tool damage and wear in a progressive die stamping factory that produces automotive metal washers have been identified by means of FEA simulations. In this study, the progressive die stamping of a dented conical washer is simulated with Transvalor FORGE FEA software by implementing the process parameters used in a real case. In this study, two indicators called FEAwear and FEAdamage are proposed for prediction of die wear and damage for tools with high risk of failure. For validating the accuracy of the FEA simulations, dimension and geometry comparisons are performed between FEA and real washer, and then real and FEA maximum press force comparison is performed. In the end, FEA simulations demonstrated their accuracy in predicting the stamping force of the press and the final part quality, and proposed FEA damage and wear indicators accurately predicted the most critical tools and stations, as confirmed by the real maintenance data. Finally, the simulations also correctly detected potential damage zones of the tools.

Optimization of the Car Body Elements’ Stamping Process Based on the Strain Analysis

“…A correctly defined material model requires the determination of sheet metal properties, including flat and normal anisotropy, the forming limit curve (FLC), and the work hardening curve [8][9][10][11][12][13]. The design process supported by numerical modeling allows for the development of shaping technology and designing the geometry of the die, punch, blank holder, and blank [14][15][16][17][18][19].…”

A Data-Based Tool Failure Prevention Approach in Progressive Die Stamping

“…Progressive die stamping is especially challenging because multiple tools and multiple signals are the cause of a cumbersome "curse of dimensionality" [21] to any control or optimization process. To make things worse, when progressive die stamping involves tiny components, such as washers [22], a single tooling setup can include more than 50 tools simultaneously operating and the stamping rate can be as high as several hundreds of strokes per minutes. In this case, not only are technologies required for the real-time handling of a very big amount of data [23], but smart methods are needed for the filtering and compression of process signals [24].…”

“…The non-dimensional tool wear indicator FEA wear , computed from the FEM simulations as the ratio between the highest shear stress acting on the tool surface during stamping and the Vickers hardness of the tool surface (formulation described in reference [22];…”

“…The non-dimensional tool failure indicator FEA damage , defined as the difference between the maximum von Mises stress detected on the tools and the residual stress on the tool coating, with normalised division by the yield stress of the die [22].…”