TY - JOUR

T1 - Constitutive modeling and deformation analysis for the ultrasonic-assisted incremental forming process

AU - Li, Yanle

AU - Cheng, Zinan

AU - Chen, Xiaoxiao

AU - Long, Yangyang

AU - Li, Xiaoqiang

AU - Li, Fangyi

AU - Li, Jianfeng

AU - Twiefel, Jens

N1 - Funding Information: This work is financially supported by National Natural Science Foundation of China (51605258), Postdoctoral Innovation Project of Shandong Province (201701011), Young Scholars Program of Shandong University (2018WLJH55), and State Key Laboratory of High Performance Complex Manufacturing, Central South University (Kfkt2017-04).

PY - 2019/10

Y1 - 2019/10

N2 - The application of high-frequency vibration on the incremental forming process could cause changes in the plasticity of material which may contribute to the reduction of forming force, the increase of formability, and the improvement of surface finish. The present work aims to deepen the understanding of the softening effect to facilitate the accurate prediction of the ultrasonic-assisted forming process. First, a theoretical model describing the relationship between the stress and strain during the ultrasonic-assisted incremental sheet forming (UISF) was established based on the theory of crystal plasticity. In particular, the acoustic softening effect was reflected by adjusting the thermal activation process and the dislocation density evolution process. Then, the constitutive model parameters were identified through the back propagation (BP) neural network based on the experimental results. In addition, the developed model was used to simulate the UISF process by ANSYS/LS-DYNA software, and the effect of ultrasonic vibration on the deformation behavior was revealed. The results show that the FE model with the modified constitutive model considering the softening effect can improve the prediction accuracy.

AB - The application of high-frequency vibration on the incremental forming process could cause changes in the plasticity of material which may contribute to the reduction of forming force, the increase of formability, and the improvement of surface finish. The present work aims to deepen the understanding of the softening effect to facilitate the accurate prediction of the ultrasonic-assisted forming process. First, a theoretical model describing the relationship between the stress and strain during the ultrasonic-assisted incremental sheet forming (UISF) was established based on the theory of crystal plasticity. In particular, the acoustic softening effect was reflected by adjusting the thermal activation process and the dislocation density evolution process. Then, the constitutive model parameters were identified through the back propagation (BP) neural network based on the experimental results. In addition, the developed model was used to simulate the UISF process by ANSYS/LS-DYNA software, and the effect of ultrasonic vibration on the deformation behavior was revealed. The results show that the FE model with the modified constitutive model considering the softening effect can improve the prediction accuracy.

KW - Acoustic softening

KW - Constitutive model

KW - Finite element simulation

KW - Incremental sheet forming

KW - Ultrasonic-assisted forming

UR - http://www.scopus.com/inward/record.url?scp=85068779260&partnerID=8YFLogxK

U2 - 10.1007/s00170-019-04031-3

DO - 10.1007/s00170-019-04031-3

M3 - Article

AN - SCOPUS:85068779260

VL - 104

SP - 2287

EP - 2299

JO - International Journal of Advanced Manufacturing Technology

JF - International Journal of Advanced Manufacturing Technology

SN - 0268-3768

IS - 5-8

ER -