Fracture Prediction for High-strength Steel Sheet Subjected to Draw-bending Using Forming Limit Stress Criterion

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

Sekiguchi, C.^1 ; Hakoyama, T.^2 ; Kuwabara, T.^3 ; Fukiharu, H.^4

Graduate School, Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan^1

Institute of Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan^2

Division of Advanced Mechanical Systems Engineering, Institute of Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan^3

Engineering Technology Division, CAE Technology Department, JSOL Corporation, Tokyo, Japan^4

关键词: Draw-bending;    Drawing speed;    Forming limits;    Fracture criteria;    Fracture prediction;    Plane strain tension;    Test materials;    Tube expansion;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/734/3/032012/pdf
DOI  :  10.1088/1742-6596/734/3/032012

来源: IOP

【 摘 要 】

A fracture criterion for sheet metals subjected to draw-bending is investigated using the concept of the forming limit stress criterion. The test material used is a 1.0-mm-thick high- strength steel sheet with a tensile strength of 590MPa. The specimen undergoes bendingunbending under tension when passing over the die profile. The drawing speed was set to 5-100 mm • s-1. The magnitude of true stress σDBwhen a specimen fractured has been precisely determined. Moreover, multiaxial tube expansion tests of the test material are performed to measure the forming limit stress σPTof the test material under plane-strain tension. It is found that σDBis larger than σPTby 2.8-6.3%. Therefore, it is concluded that the forming limit stress criterion is effective as a fracture criterion in draw-bending.