scholarly journals Multi-scale modelling of the development of heterogeneous distributions of stress, strain, deformation texture and anisotropy in sheet metal forming

2012 ◽  
Vol 3 ◽  
pp. 67-75 ◽  
Author(s):  
P. Van Houtte ◽  
J. Gawad ◽  
P. Eyckens ◽  
B. Van Bael ◽  
Giovanni Samaey ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Deformation Texture ◽  
Stress Strain ◽  
Multi Scale ◽  
Scale Modelling

Stress-Based Forming Limits in Sheet-Metal Forming

2000 ◽  
Vol 123 (4) ◽  
pp. 417-422 ◽  
Author(s):  
Thomas B. Stoughton
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Strain Path ◽  
Forming Limit ◽  
Stress Strain ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
The Stability ◽  
Definition Of

A strain-based forming limit criterion is widely used throughout the sheet-metal forming industry to gauge the stability of the deformed material with respect to the development of a localized neck prior to fracture. This criterion is strictly valid only when the strain path is linear throughout the deformation process. There is significant data that shows a strong and complex dependence of the limit criterion on the strain path. Unfortunately, the strain path is never linear in secondary forming and hydro-forming processes. Furthermore, the path is often found to be nonlinear in localized critical areas in the first draw die. Therefore, the conventional practice of using a path-independent strain-based forming limit criterion often leads to erroneous assessments of forming severity. Recently it has been reported that a stress-based forming limit criterion appears to exhibit no strain-path dependencies. Subsequently, it has been suggested that this effect is not real, but is due to the saturation of the stress-strain relation. This paper will review and compare the strain-based and stress-based forming limit criteria, looking at a number of factors that are involved in the definition of the stress-based forming limit, including the role of the stress-strain relation.

Multi-scale friction modeling for sheet metal forming: The boundary lubrication regime

2015 ◽  
Vol 81 ◽  
pp. 112-128 ◽  
Author(s):  
J. Hol ◽  
V.T. Meinders ◽  
M.B. de Rooij ◽  
A.H. van den Boogaard
Keyword(s):  
Sheet Metal ◽  
Boundary Lubrication ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Friction Modeling ◽  
Multi Scale ◽  
Lubrication Regime

Multi-Scale Contact Modeling of Coated Steels for Sheet Metal Forming Applications

2018 ◽  
Vol 767 ◽  
pp. 223-231 ◽  
Author(s):  
Meghshyam Shisode ◽  
Javad Hazrati ◽  
Tanmaya Mishra ◽  
Matthijn de Rooij ◽  
Ton van den Boogaard
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Normal Load ◽  
Steel Substrate ◽  
Surface Textures ◽  
The Real ◽  
Multi Scale ◽  
Real Area Of Contact ◽  
Real Area

Friction in sheet metal forming is a local phenomenon which depends on continuously evolving contact conditions during the forming process. This is mainly influenced by local contact pressure, surface textures of the sheet metal as well as the forming tool surface profile and material behavior. The first step for an accurate prediction of friction is to reliably estimate real area of contact at various normal loads. In this study, a multi-scale contact model for the normal load is presented to predict asperity deformation in coated steels and thus to estimate the real area of contact. Surface profiles of the zinc layer and steel substrate are modelled explicitly obtained from confocal measurements. Different mechanical properties are assigned to the zinc coating and the steel substrate. The model was calibrated and validated relative to lab-scale normal load tests using different samples of zinc coated steel with distinct surface textures. The results show that the model is able to predict the real area of contact in zinc-coated steels for various contact pressures and different surface textures. Current multi-scale model can be used to determine the local friction coefficient in sheet metal forming processes more accurately.

Springback analysis in sheet metal forming by using the Ramberg–Osgood stress–strain relation

2016 ◽  
Vol 57 (6) ◽  
pp. 1133-1140 ◽  
Author(s):  
R. K. Lal ◽  
M. K. Bhagat ◽  
J. P. Dwivedi ◽  
V. P. Singh ◽  
S. K. Patel
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Stress Strain ◽  
Strain Relation ◽  
Stress Strain Relation

scholarly journals Springback Analysis in Sheet Metal Forming Using Modified Ludwik Stress-Strain Relation

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Sanjay Kumar Patel ◽  
Radha Krishna Lal ◽  
J. P. Dwivedi ◽  
V. P. Singh
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Spring Back ◽  
Stress Strain ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Strain Relationship ◽  
Von Mises ◽  
Strain Hardening Index

This paper deals with the springback analysis in sheet metal forming using modified Ludwik stress-strain relation. Using the deformation theory of plasticity, formulation of the problem and spring back ratio is derived using modified Ludwik stress strain relationship with Tresca and von Mises yielding criteraia. The results have been representing the effect of different value of or ratio, different values of Strain hardening index (), Poisson’s ratio (), and thickness on spring back ratio (). The main aim of this paper is to study the effects of the thickness, ratio, and Poisson’s ratio in spring back ratio.

Sign in / Sign up

Export Citation Format

Share Document