Development of new hole expansion testing method

10th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes

Kim, Hyunok^1 ; Shang, Jianhui^1 ; Beam, Kevin^2 ; Samant, Anoop^2 ; Hoschouer, Cliff^3 ; Dykeman, Jim^4

EWI Forming Center, 1250 Arthur E. Adams Drive, Columbus

OH

43221, United States^1

KTH Parts Industries Inc., K-Group Technical RandD Center, 8205 Business Way, Plain City

OH

43064, United States^2

SHILOH, 5580 Wegman Drive, Valley City

OH

44280, United States^3

Honda RandD of Americas, Inc., 21001 State Route 739, Raymond

OH

43067, United States^4

关键词: Advanced high strength steel;    Edge cracking;    Effects of materials;    Hole expansions;    In-line monitoring;    Initial cracks;    Load-displacement data;    Testing method;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/734/3/032025/pdf
DOI  :  10.1088/1742-6596/734/3/032025

来源: IOP

【 摘 要 】

This paper introduces a new hole expansion (HE) testing method that could be more relevant to the edge cracking problem observed in stamping advanced high strength steel (AHSS). The new testing method adopted a large hole diameter of 75 mm compared to the standard hole diameter of 10 mm. An inline monitoring system was developed to visually monitor the hole edge cracking during the test and synchronize the load-displacement data with the recorded video for capturing the initial crack. A new hole expansion testing method was found to be effective in evaluating the edge cracking by considering the effects of material properties and trimming methods. It showed a much larger difference, up to 11%, of the HE ratio between DP980 and TRIP780 compared to the standard HE testing method giving less than a 2% difference.