A Practical Methodology to Evaluate and Predict Edge Cracking for Advanced High-Strength Steel

International Deep Drawing Research Group 37th Annual Conference

Gu, J.C.^1 ; Kim, H.^1 ; Dykeman, J.^2 ; Shih, H.^3

Materials Forming Group, EWI Inc., 1250 Arthur E Adams Dr, Columbus

OH

43221, United States^1

Honda RandD Americas, Inc, 2101 State Route 739, Raymond

OH

43067, United States^2

Global Product Development and Engineering, United States Steel Corp., 5850 New King Court, Troy

MI

48098-2692, United States^3

关键词: Advanced high strength steel;    Digital image correlations;    Edge conditions;    Failure criteria;    FEA simulation;    Good correlations;    Load-displacement curve;    Material thickness;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/418/1/012072/pdf
DOI  :  10.1088/1757-899X/418/1/012072

来源: IOP

【 摘 要 】

With the increased application of advanced high strength steel (AHSS), the development of a reliable methodology for evaluating and predicting edge cracking is in high demand. In this study, different shear edge conditions of three different AHSS materials, TRIP 780, DP 980, and DP 1180, were evaluated. The edge cracking is evaluated in four steps: shear test, sheared edge characterization, HSDT, and prediction of edge cracking using FEA. The shear edges were prepared with five different shear clearances between 5 and 25% of the material thickness to obtain variable shear quality. In the HSDT, the strain and thinning distribution is captured using a digital image correlation system as the edge cracking limit and failure criteria in FEA. The preferred shear clearance is characterized by the largest stroke in HSDT and highest thinning value of the onset of edge cracking. FEA showed good correlations with the experiment comparing strain and load-displacement curves. The optimized shear clearance for TRIP 780 is 15% material thickness which for DP 980 and DP 1180 is 20%. By comparing test results from shear test, HSDT and FEA simulation, the peak shear load and burr height from simple experiment observation were found to be important indicators of edge condition, which can be monitored in production.