On capturing rate-dependent anisotropic behavior of sheet metal forming using a viscoplastic computational framework

Abstract

Manufacturing of metal sheets—of critical importance in the automotive, aerospace, and railway industries; is notoriously prone to uncertainty and inaccuracy driven by the lack of control in responding to anisotropic behavior developed during a rate-dependent forming process. Various expensive efforts have been made to evaluate these complex behaviors largely based on trial-and-error approaches, implying a high-fidelity predictive numerical tool is inevitable to promote a cost-effective solution. In this work, a high fidelity anisotropic-viscoplastic constitutive model framework based on Hill 48 yield function, isotropic hardening, and Cowper-Symonds viscoplasticity is developed to investigate the rate-dependent anisotropic behavior of sheet metals. This model is holistically implemented as a user-defined material subroutine (VUMAT) in ABAQUS software. The quality of numerical results is evaluated through comparison with experimental works. In the quasi-static and dynamic tensile test, the stress-strain curves obtained from numerical simulation using the developed constitutive model are in excellent agreement with experimental results. Furthermore, numerical simulation of cup drawing test using the developed constitutive model can accurately predict the earing height compared to experimental results. In addition, some novel relationships in terms of plastic rate-dependent anisotropic behavior of sheet metal forming are successfully established through the extended use of the validated numerical model.

Keywords:

• Anisotropy
• viscoplasticity
• constitutive modeling
• sheet metal
• drawing process
• manufacturing

Authors’ contributions

Afdhal carried out the research and drafted the manuscript. Leonardo Gunawan supervised the research program, reviewing the research results and manuscript. Tatacipta Dirgantara coordinated the research and participated in reviewing the manuscript. Sigit Santosa participated in supervising the research and reviewing some technical aspects of modeling. Fauzan Adziman contributed to the technical problem, especially in the modeling technique, and participated in reviewing the manuscript. Ditho A. Pulungan contributed to the technical problem especially in the subroutine development.

Disclosure statement

The authors declare that they have no competing interests.

Additional information

Funding

The authors gratefully acknowledge the financial support from the Royal Academy of Engineering UK through Newton Fund IAPP scheme 2017–2018. The authors also would like to thank Institut Teknologi Bandung for the research funding through Riset Multidisiplin 2020 and P2MI 2020 scheme.