Modeling Temperature and Strain Rate Dependent Large Deformations of Metals

1990 ◽  
Vol 43 (5S) ◽  
pp. S312-S319 ◽  
Author(s):  
Douglas J. Bammann
Keyword(s):  
Strain Rate ◽  
Large Deformations ◽  
Uniaxial Stress ◽  
Thermal Softening ◽  
Plasticity Model ◽  
Anisotropic Hardening ◽  
Temperature Dependent ◽  
History Effects ◽  
Rate Dependent ◽  
Comparison With Experimental Data

We review the development of a strain rate and temperature dependent plasticity model for finite deformation. In particular we address both the method of determining the parameters of the model and the engineering meaning of the parameters in terms of uniaxial stress-strain curves. The ability of the model to predict some aspects of anisotropic hardening, strain rate history effects, and thermal softening are then illustrated by comparison with experimental data.

Thermoviscoplastic Analysis of First Walls Subjected to Fusion Power Transients

1983 ◽  
Vol 105 (1) ◽  
pp. 42-51 ◽  
Author(s):  
H. L. Schreyer ◽  
J. M. Kennedy ◽  
D. F. Schoeberle
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
Thermal Stresses ◽  
Large Deformations ◽  
Computer Code ◽  
Thermal Softening ◽  
Fusion Reactors ◽  
Fusion Power ◽  
Wide Range ◽  
Safety Features

Abrupt thermal fluxes on the first walls of fusion reactors represent a loading environment that requires advanced analytical capabilities. Solutions are needed to a wide range of postulated conditions to provide guidance for safety features and design modifications. A brief outline is given of a computer code that provides an integrated procedure for handling thermal stresses and large deformations under dynamic conditions. The code includes a new thermoviscoplastic constitutive equation that incorporates thermal softening, failure and strain rate. Solutions to several verification and illustrative problems are given.

Rate-Dependent Behavior and Constitutive Model of Polycarbonate at Strain Rate from 10-5 to 103 S-1

2011 ◽  
Vol 117-119 ◽  
pp. 434-437
Author(s):  
Wen Jun Hu ◽  
Xi Cheng Huang ◽  
Fang Ju Zhang ◽  
Cheng Jun Chen
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Temperature Dependent ◽  
Static Tests ◽  
Rate Range ◽  
Rate Dependent ◽  
Dependent Behavior

Uni-axial quasi-static tests at strain rates 10-5, 10-4, 10-3,10-2 and 10-1 s-1 and dynamic compressive tests at strain rates 1679, 2769,5000 and 8200 s-1 have been carried out to study the mechanical behavior for polycarbonate used in the avigation industry. The stress–strain curves of polycarbonate in the strain-rate range from 10-5 to 8200 s-1 have been obtained. The effects of the strain rate on yield phenomenon and rate-dependent mechanical behavior are discussed. A plastic flow law based on the DSGZ rate-temperature-dependent constitutive model was used to describe the mechanical behavior of polycarbonate in the strain-rate range from 10-5 to 103 s-1. The results at the six strain rates are in excellent agreement with the experimental data, which illustrates that the constitutive model can describe the mechanical behavior for polycarbonate at low and high strain rates perfectly.

Further investigation of crystal hardening inequalities in (110) channel die compression

2008 ◽  
Vol 464 (2096) ◽  
pp. 1955-1982 ◽  
Author(s):  
Kerry S Havner
Keyword(s):  
Large Deformations ◽  
Lattice Stability ◽  
Slip Systems ◽  
Plasticity Model ◽  
Experimental Stress ◽  
Rate Dependent ◽  
Load Axis ◽  
Lateral Constraint ◽  
Constraint Stress ◽  
Latent Hardening

A set of geometrically based FCC crystal slip-systems hardening inequalities is analytically investigated in (110) channel die compression for all lateral constraint directions between and , following previous analyses of the other two distinct orientation ranges in (110) compression. With all critical slip systems active, it is proved that these inequalities uniquely predict initial lattice stability and finite crystal shearing only in the horizontal channel plane, consistent with experiments for this range of orientations. (The earlier analyses had predicted load-axis stability in both orientation ranges, and lattice stability in one, also commonly found experimentally.) Moreover, it is established that the lateral constraint stress predicted by the hardening inequalities will be less than that given by classic Taylor hardening as this stress evolves with deformation. It is further shown, taking into account experimental stress–strain curves and latent hardening experiments for aluminium and copper, that lattice stability generally can be expected to very large deformations, except perhaps for lateral constraint orientations near the end of the range, which result is consistent with experiment. In appendix A, the possibilities of solutions with a critical slip system inactive are investigated, and predictions of a power law rate-dependent plasticity model are analysed for comparison with the results based on the hardening inequalities.

Analytical Formulation of a Rate and Temperature Dependent Stress-Strain Relation

1979 ◽  
Vol 101 (3) ◽  
pp. 254-257 ◽  
Author(s):  
A. Merzer ◽  
S. R. Bodner
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Uniaxial Stress ◽  
Plastic Strain Rate ◽  
Isotropic Hardening ◽  
Stress Strain ◽  
Rate Dependent ◽  
Strain Relation ◽  
Strain And Strain Rate ◽  
Stress Strain Relation

The equation for plastic strain rate in the Bodner-Partom viscoplastic formulation is integrated under conditions of uniaxial stress, constant plastic strain rate, and isotropic hardening to give an analytical expression for the stress as a function of plastic strain and strain rate. Temperature dependence is introduced which leads to a general relationship between stress, strain, strain rate, and temperature. The resulting equation indicates an asymptotic saturation stress whose dependence on strain rate and temperature appears to agree with experimental results. Strain hardening given by the analytical equation also seems to be consistent with experiments. A possible new definition of yield stress is a consequence of the rate dependent stress-strain relation.

scholarly journals Strain Rate Dependent Constitutive Modelling of 3D Printed Polymers

2021 ◽  
Vol 250 ◽  
pp. 02029
Author(s):  
Maria Lißner ◽  
Daniel Thomson ◽  
Nik Petrinic ◽  
Jeroen Bergmann
Keyword(s):  
Strain Rate ◽  
Large Deformations ◽  
Material Model ◽  
Constitutive Modelling ◽  
Experimental Results ◽  
Good Representation ◽  
Material Models ◽  
Rate Dependent ◽  
3D Printed ◽  
Dependent Behaviour

Experimental results from 3D printed TPC (thermoplastic copolyester) compression specimens were used to develop a combined experimental-numerical framework to support the design of e.g. 3D printed mouthguards. First, a commercially available material model capable of representing the strain-rate dependent behaviour of materials undergoing large deformations is identified. Second, experimental results from solid 3D printed compression specimens are used to calibrate the identified material models. Third, 3D printed compression specimens with two different cavity geometries are used to assess the ability of the material model to accurately reproduce the experimental observations. The numerical investigation indicates a good representation of the strain rate dependent experimental results of 3D printed specimens.

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