A Triaxial Failure Diagram to predict the forming limit of 3D sheet metal parts subjected to multiaxial stresses

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

Rastellini, F.^1,2 ; Socorro, G.^1 ; Forgas, A.^1 ; Onate, E.^1,2,3

Quantech ATZ S.A., c/ Gran Capitan 2-4, Barceloña

08034, Spain^1

Centre International de Métodes Numérics en Enginyeria (CIMNE), Spain^2

Universitat Politécnica de Catalunya (UPC), c/ Jordi Girona 3, Barcelona, Spain^3

关键词: Accurate prediction;    Effective plastic strain;    Forming limit curve;    Multiaxial stress;    Numerical predictions;    Sheet metal parts;    Stress triaxility;    Triaxial failures;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/734/3/032020/pdf
DOI  :  10.1088/1742-6596/734/3/032020

来源: IOP

【 摘 要 】

Accurate prediction of failure and forming limits is essential when modelling sheet metal forming processes. Since traditional Forming Limit Curves (FLCs) are not valid for materials subjected to triaxial loading, a new failure criterion is proposed in this paper based on the stress triaxility and the effective plastic strain accumulated during the history of material loading. Formability zones are identified inside the proposed Triaxial Failure Diagram (TFD). FLCs may be mapped into the TFD defining a new Triaxial Failure Curve, or it can be defined by triaxial failure experiments. Several TFD examples are validated and constrasted showing acceptable accuracy in the numerical prediction of forming failure/limit of 3D thick sheet parts.