scholarly journals Strain rate dependent hardening of DP600 sheet metal for large strains under in-plane biaxial loadings

2016 ◽  
Author(s):  
W. Liu ◽  
D. Guines ◽  
L. Léotoing ◽  
E. Ragneau
Keyword(s):  
Strain Rate ◽  
Sheet Metal ◽  
Large Strains ◽  
Rate Dependent

Enhancement in the Modeling of Temperature and Strain Rate-Dependent Plastic Hardening Behavior of a Sheet Metal

2015 ◽  
Vol 86 (8) ◽  
pp. 902-914 ◽  
Author(s):  
Dohyun Leem ◽  
Hyuk-Jong Bong ◽  
Frederic Barlat ◽  
Myoung-Gyu Lee ◽  
Jung-Han Song ◽  
...  
Keyword(s):  
Strain Rate ◽  
Sheet Metal ◽  
Hardening Behavior ◽  
Rate Dependent ◽  
Plastic Hardening

scholarly journals Characterization of Flow Induced Anisotropy in Sheet Metal at Large Strain

2021 ◽  
Author(s):  
F. Gutknecht ◽  
H. Traphöner ◽  
T. Clausmeyer ◽  
A. E. Tekkaya
Keyword(s):  
Strain Rate ◽  
Sheet Metal ◽  
Strain Path ◽  
Large Strain ◽  
High Strength ◽  
Bulge Test ◽  
Large Strains ◽  
Steel Grades ◽  
Strain Path Change ◽  
Cross Hardening

Abstract Background Many metals exhibit a stress overshoot, the so-called cross-hardening when subjected to a specific strain-path change. Existing tests for sheet metals are limited to an equivalent prestrain of 0.2 and show varying levels of cross-hardening for identical grades. Objective The aim is to determine cross-hardening at large strains, relevant for forming processes. Mild steel grades (DC04, DC06, DX56) and high strength steel grades (BS600, DP600, ZE800) are investigated to quantify the level of cross-hardening between different grades and reveal which grades exhibit cross-hardening at all. Method A novel test setup for large prestrain using hydraulic bulge test and torsion of curved sheets is developed to achieve an orthogonal strain-path change, i.e. the strain rate tensors for two subsequent loadings are orthogonal. The influence of strain rate differences between the tests and clamping of curved sheets on the determined cross-hardening are evaluated. The results are compared to experiments in literature. Results Cross-hardening for sheet metal at prestrains up to 0.6 true plastic strain are obtained for the first time. For DX56 grade the maximum cross-hardening for all prestrains have a constant level of approximately 6%, while the maximum cross-hardening for DC04 and DC06 grades increases, with levels between 7 and 11%. The high strength grades BS600 and ZE800 do not show cross-hardening behavior, while, differencing from previous publications, cross-hardening is observed for dual phase steel DP600. Conclusion Depending on the microstructure of the steel grade the cross-hardening increases with large prestrain or remains constant.

Investigation of the Anisotropic Strain Rate Dependency of AA5182-O and DC04 for Different Stress States

2016 ◽  
Vol 1140 ◽  
pp. 35-42 ◽  
Author(s):  
Matthias Lenzen ◽  
Emanuela Affronti ◽  
Martin Rosenschon ◽  
Marion Merklein
Keyword(s):  
Strain Rate ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Equivalent Stress ◽  
Sheet Metals ◽  
Forming Process ◽  
Rate Dependent ◽  
Material Characteristics ◽  
Deformation Velocity

A more precise numerical simulation of sheet metal forming processes leads to a demand for more detailed material characterisation. Hence, it is advisable to consider the strain rate reliant and anisotropic material characteristics. There are various common sheet metals that have beside of an anisotropic a more or less distinct strain rate dependent material behaviour. With regard to these material characteristics, for a more detailed numerical prediction of a sheet metal forming process, it is necessary to include the aspect of deformation velocity. A characterisation of the strain rate dependent hardening behaviour for the two common sheet metals DC04 and AA5182-O is performed under tensile as well as shear load and their behaviour is compared after v. Mises equivalent stress and strain. The two strain rate models from Norton-Hoff and Tanimura are calibrated on basis of the experimental data and their applicability for the investigated materials is evaluated. The calibration of the strain rate sensitive models showed for both materials a very good comparability, respectively.

Large Strain, High Strain Rate Testing of Copper

1980 ◽  
Vol 102 (4) ◽  
pp. 376-381 ◽  
Author(s):  
U. S. Lindholm ◽  
A. Nagy ◽  
G. R. Johnson ◽  
J. M. Hoegfeldt
Keyword(s):  
Strain Rate ◽  
High Speed ◽  
Large Strain ◽  
Shear Banding ◽  
Testing Machine ◽  
Shear Instability ◽  
Large Strains ◽  
Rate Dependent ◽  
Torsional Testing ◽  
Strain Hardening Behavior

This paper describes the development of a high-speed torsional testing machine and results obtained on the strain-rate dependent strength of copper at large shear strains. Test techniques and data obtained are intended to be useful in applications such as ballistics and machining. For copper, the results indicate positive strain hardening behavior to very large strains under low rate, isothermal conditions and the transition to adiabatic thermal softening, shear instability and localization (shear banding) at high rates.

Strain-rate dependent material properties of selective laser melted AlSi10Mg and AlSi3.5Mg2.5

2020 ◽  
Vol 62 (6) ◽  
pp. 573-583
Author(s):  
Andreas Lutz ◽  
Lukas Huber ◽  
Claus Emmelmann
Keyword(s):  
Strain Rate ◽  
Material Properties ◽  
Rate Dependent

Strain-Rate Dependent Deformation Behavior in WC-10 wt%Ni 3Al Cermet Micropillars Under Uniaxial Compression

2019 ◽  
Author(s):  
Minai Zhang ◽  
Xin Wang ◽  
Alexander D. Dupuy ◽  
Julie M. Schoenung ◽  
Xiaoqiang Li
Keyword(s):  
Strain Rate ◽  
Uniaxial Compression ◽  
Deformation Behavior ◽  
Rate Dependent

Analytical Solutions for Circular Bars Subjected to Large Strain Plastic Torsion

1990 ◽  
Vol 57 (2) ◽  
pp. 298-306 ◽  
Author(s):  
K. W. Neale ◽  
S. C. Shrivastava
Keyword(s):  
Closed Form ◽  
Analytical Solutions ◽  
Large Strain ◽  
Kinematic Hardening ◽  
Flow Theory ◽  
Constitutive Laws ◽  
Isotropic Hardening ◽  
Large Strains ◽  
Inelastic Behavior ◽  
Rate Dependent

The inelastic behavior of solid circular bars twisted to arbitrarily large strains is considered. Various phenomenological constitutive laws currently employed to model finite strain inelastic behavior are shown to lead to closed-form analytical solutions for torsion. These include rate-independent elastic-plastic isotropic hardening J2 flow theory of plasticity, various kinematic hardening models of flow theory, and both hypoelastic and hyperelastic formulations of J2 deformation theory. Certain rate-dependent inelastic laws, including creep and strain-rate sensitivity models, also permit the development of closed-form solutions. The derivation of these solutions is presented as well as numerous applications to a wide variety of time-independent and rate-dependent plastic constitutive laws.

scholarly journals Identification of the LLDPE Constitutive Material Model for Energy Absorption in Impact Applications

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1537
Author(s):  
Luděk Hynčík ◽  
Petra Kochová ◽  
Jan Špička ◽  
Tomasz Bońkowski ◽  
Robert Cimrman ◽  
...  
Keyword(s):  
Strain Rate ◽  
Material Model ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Stress Strain ◽  
Rate Dependent ◽  
Constitutive Material Model ◽  
Principal Directions ◽  
Constitutive Material

Current industrial trends bring new challenges in energy absorbing systems. Polymer materials as the traditional packaging materials seem to be promising due to their low weight, structure, and production price. Based on the review, the linear low-density polyethylene (LLDPE) material was identified as the most promising material for absorbing impact energy. The current paper addresses the identification of the material parameters and the development of a constitutive material model to be used in future designs by virtual prototyping. The paper deals with the experimental measurement of the stress-strain relations of linear low-density polyethylene under static and dynamic loading. The quasi-static measurement was realized in two perpendicular principal directions and was supplemented by a test measurement in the 45° direction, i.e., exactly between the principal directions. The quasi-static stress-strain curves were analyzed as an initial step for dynamic strain rate-dependent material behavior. The dynamic response was tested in a drop tower using a spherical impactor hitting a flat material multi-layered specimen at two different energy levels. The strain rate-dependent material model was identified by optimizing the static material response obtained in the dynamic experiments. The material model was validated by the virtual reconstruction of the experiments and by comparing the numerical results to the experimental ones.

Sign in / Sign up

Export Citation Format

Share Document