Optimal Designs of Automotive Stamping Dies via Integrated Forming Simulations and Die Structural Analysis

In the past few years, GM manufacturing is streamlining its efforts to win total manufacturability in stamping process. One of the major efforts is optimizing the stamping die structures to reduce the construction and operating costs. Traditionally the automotive dies are designed with high safety margin based on empirical-rules for forming tonnage estimation that is often conservative. After a huge success in predicting formability performance of line dies in forming simulations, the predicted forming forces from the formability analysis can be a good basis for die structure design to optimize the weight and structure for press line throughput improvements. The forming simulation and die structural analysis were integrated to achieve the objective of world-class solid die design. The integrated analysis comprises of extracting predicted forming loads from line die simulations and applying these forces on solid die members for structural analyses to evaluate the distributions of stress, strains, and deflections on die structure members. In GM die and stamping business, the integrated forming and die structure analysis has been adopted for various applications such as optimizing the die design, for weight reduction, validating the design changes made on legacy dies in the production plants to suit the production conditions; identifying the root cause of die breakages during the tryout and stamping operations and propose repair schemes; improving press throughput via optimizing the scrap chute openings, and providing a math-based tool to validate revisions to the current die design standards and generating new rules. In the past few years, GMNA Die Center conducted several static, dynamic and fatigue analysis for many dies that cover the die changes requested by die design, die construction and stamping production. This paper presents the technical challenges of integrating forming and die structure analysis and its importance and benefits in die and stamping business.