6
IRUS Total
Downloads

A CDM-based unified viscoplastic constitutive model of FLCs and FFLCs for boron steel under hot stamping conditions

File Description SizeFormat 
2022 IJDM - Zhang et al CDM model for FLC&FFLC.pdfPublished version1.29 MBAdobe PDFView/Open
Title: A CDM-based unified viscoplastic constitutive model of FLCs and FFLCs for boron steel under hot stamping conditions
Authors: Zhang, R
Shi, Z
Yardley, VA
Lin, J
Item Type: Journal Article
Abstract: Forming limit curves (FLCs), which are constructed using the limit strains at localised necking, are the most widely used tools for the evaluation of the formability of sheet metals. Fracture forming limit curves (FFLCs) are more recently developed, complementary tools for formability evaluation which are instead constructed using the limit strains at fracture. Since the formability depends strongly on forming conditions such as strain state, temperature and strain rate, models for predicting FLCs and FFLCs are essential for the optimisation and further application of hot forming processes in which these forming conditions vary significantly with both position and time. However, no model has so far been developed to predict FFLCs either alone or in conjunction with FLCs for sheet metals such as boron steel under hot stamping conditions. In this study, a set of unified viscoplastic constitutive equations for the prediction of both FLCs and FFLCs based on continuum damage mechanics (CDM) has been formulated from a set of recently developed constitutive equations for dislocation-based hardening, in combination with two novel coupled variables characterising the accumulated damage leading to localised necking and fracture. The novel variables take into account the effects of strain state, temperature and strain rate on the formability of sheet metals. The material constants in the CDM-based constitutive equations have been calibrated using experimental data comprising true stress-true strain curves and limit strains of a 22MnB5 boron steel obtained at a range of temperatures and strain rates. Investigation of the effect of varying selected parameters in the coupled damage variables on the resulting computed FLCs and FFLCs has demonstrated the flexibility of the model in enabling curves of different shapes and numerical values to be constructed. This indicates the potential of the CDM-based constitutive model for application to other materials for warm or hot stamping processes.
Issue Date: 1-Sep-2022
Date of Acceptance: 21-May-2022
URI: http://hdl.handle.net/10044/1/97917
DOI: 10.1177/10567895221105655
ISSN: 1056-7895
Publisher: SAGE Publications
Start Page: 1373
End Page: 1395
Journal / Book Title: International Journal of Damage Mechanics
Volume: 31
Issue: 9
Copyright Statement: ┬ęThe Author(s) 2022. This article is distributed under the terms of the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
Sponsor/Funder: Engineering & Physical Science Research Council (E
Funder's Grant Number: EP/R001715/1 / PO 2105860
Keywords: Science & Technology
Technology
Materials Science, Multidisciplinary
Mechanics
Materials Science
Forming limit curve
fracture forming limit curve
continuum damage mechanics
boron steel
hot stamping
sheet metal forming
constitutive modelling
FORMING LIMIT DIAGRAMS
BIAXIAL TESTING SYSTEM
NOTCHED TENSION BARS
DUCTILE FRACTURE
SHEET-METALS
ELEVATED-TEMPERATURES
STRAIN-RATE
MICROSTRUCTURE EVOLUTION
FORMABILITY LIMITS
STRESS TRIAXIALITY
Science & Technology
Technology
Materials Science, Multidisciplinary
Mechanics
Materials Science
Forming limit curve
fracture forming limit curve
continuum damage mechanics
boron steel
hot stamping
sheet metal forming
constitutive modelling
FORMING LIMIT DIAGRAMS
BIAXIAL TESTING SYSTEM
NOTCHED TENSION BARS
DUCTILE FRACTURE
SHEET-METALS
ELEVATED-TEMPERATURES
STRAIN-RATE
MICROSTRUCTURE EVOLUTION
FORMABILITY LIMITS
STRESS TRIAXIALITY
0905 Civil Engineering
0912 Materials Engineering
0913 Mechanical Engineering
Mechanical Engineering & Transports
Publication Status: Published
Open Access location: https://doi.org/10.1177/10567895221105655
Article Number: ARTN 10567895221105655
Online Publication Date: 2022-06-05
Appears in Collections:Mechanical Engineering
Faculty of Engineering



This item is licensed under a Creative Commons License Creative Commons