Effect of Tooling Configuration on Ability to Detect Instability in Hole Expansion Test

This study aims to analyze the impact of tooling configurations on the detection of instability during hole expansion tests. The materials investigated include high-strength steels, specifically DP600, DP780, and DP980. Experiments are conducted using an Erichsen machine. Explicit finite element models are employed to predict instability during the hole expansion process. To ensure the accuracy of the predictions, various material models are compared against experimental results, demonstrating good agreement with the data. The validated model is subsequently utilized to explore the effects of different tooling configurations. Both conical and flat cylindrical punches are used in the study, with instability monitored through thickness strain measurements.