On the nonlinear anelastic behaviour of AHSS

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

Torkabadi, A.^1 ; Meinders, V.T.^1 ; Van Den Boogaard, A.H.^1

University of Twente, P.O. Box 217, Enschede

7500 AE, Netherlands^1

关键词: Deformed metals;    Dual-phase steel;    Elastic strain;    Hysteresis behaviour;    Micro mechanisms;    Reversible strain;    Spring-back;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/734/3/032100/pdf
DOI  :  10.1088/1742-6596/734/3/032100

来源: IOP

【 摘 要 】

It has been widely observed that below the yield stress the loading/unloading stress-strain curves of plastically deformed metals are in fact not linear but slightly curved, showing a hysteresis behaviour during unloading/reloading cycles. In addition to the purely elastic strain, extra dislocation based micro-mechanisms are contributing to the reversible strain of the material which results in the nonlinear unloading/reloading behaviour. This extra reversible strain is the so called anelastic strain. As a result, the springback will be larger than that predicted by FEM considering only the recovery of the elastic strain. In this work the physics behind the anelastic behaviour is discussed and experimental results for a dual phase steel are demonstrated. Based on the physics of the phenomenon a model for anelastic behaviour is presented that can fit the experimental results with a good accuracy.