scholarly journals Viscoplastic flow of functional cellular materials with use of peridynamics

Meccanica ◽  
2021 ◽  
Author(s):  
Eligiusz Postek ◽  
Zdzisław Nowak ◽  
Ryszard B. Pęcherski
Keyword(s):  
Strain Rate ◽  
Copper Sample ◽  
Metallic Foam ◽  
Viscoplastic Flow ◽  
Hardening Effect ◽  
Load Carrying ◽  
Open Cell Foam ◽  
Taylor Impact ◽  
The Subject ◽  
Strain Rate Hardening

AbstractThe subject of the study is the deformation of the oxygen-free high conductivity copper. The copper sample is given in the form of a foam. The sample undergoes an impact into an elastic wall. The strain rate hardening effect is investigated. The numerical model of the open-cell foam skeleton is prepared in the framework of the peridynamics method. The dynamic process of compression with different impact velocities is simulated. It has been found that the strain rate hardening effect is essential for the load-carrying capacity of the material under study. Taylor impact test of solid cylinder analysis precedes the analysis of the metallic foam.

High-Strain-Rate Response of a Specially-Made Copper Sample

2015 ◽  
Vol 817 ◽  
pp. 35-41
Author(s):  
Dong Mei Liu ◽  
Qiang Song Wang ◽  
Guo Liang Xie ◽  
Wei Bin Xie ◽  
Yang Li ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Temperatures ◽  
High Strain ◽  
Copper Sample ◽  
Dislocation Slip ◽  
Softening Effect ◽  
Hardening Effect ◽  
Dynamic Recrystallization Behavior ◽  
Strain Rate Hardening

In the present study, a systematic study on both the high strain-rate tensile and compressive deformation behaviors of a specially-made copper sample have been carried out at different high temperatures, by using the split Hopkinson bar experiments. The Johnson-Cook constitutive model was used to model the high strain-rate responses of the specimen at high temperatures. The results showed that compared with other metallic materials, the specially-made copper sample had a relatively stronger strain-rate-hardening effect and weaker temperature-softening effect. Evolution of the microstructure suggests that under high strain-rate, both the dislocation slip and deformation twins contribute to the plastic strengthening of the copper specimen, resulting in the strain-rate-hardening effect. And the dynamic recrystallization behavior plays an important role during the high strain-rate deformation process at the high temperatures.

Mechanical Behavior and Constitutive Equation of Concrete under High-Temperature Dynamical Conditions

2011 ◽  
Vol 228-229 ◽  
pp. 303-308
Author(s):  
Bin Jia ◽  
Zheng Liang Li ◽  
Jun Lin Tao ◽  
Chun Tao Zhang
Keyword(s):  
High Temperature ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Test Data ◽  
Dynamical Behavior ◽  
Hardening Effect ◽  
Failure Evolution ◽  
Different Temperatures ◽  
Strain Rate Hardening

SPHB tests of concrete under different temperatures and various loading conditions are completed, and high-temperature dynamical behavior of concrete is obtained. Dynamical mechanical behavior of concrete with high temperature is affected by not only the strain rate effect, but also the high temperature weakening effect, and the strain rate hardening effect is coupled with high temperature weakening effect, but the latter has greater influence. Concrete failure evolution is described on basis of the damage factor, the intercoupling strain rate hardening effect and temperature weakening effect are simply set as mutually independent factors, each parameter is respectively fitted with test data, finally, concrete constitutive equation under high-temperature dynamical conditions is established, and comparative analysis with test data are conducted, indicating good coincidence with test results.

High Temperature High Strain-Rate Tensile and Compressive Deformation Behaviors of Cu-Zn-Sn-Al Alloy

2015 ◽  
Vol 817 ◽  
pp. 55-62
Author(s):  
Qiang Song Wang ◽  
Dong Mei Liu ◽  
Guo Liang Xie ◽  
Wei Bin Xie ◽  
Yang Li ◽  
...  
Keyword(s):  
High Temperature ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Al Alloy ◽  
Softening Effect ◽  
Α Phase ◽  
Hardening Effect ◽  
Deformation Behaviors ◽  
Strain Rate Hardening

The present work gives a systematic study on the high temperature and high strain-rate deformation behaviors of a two-phase α/β Cu-Zn-Sn-Al alloy, by combining the split Hopkinson bar experiments and microstructural investigations. The results show that under high strain-rate, both the dislocation slip and deformation twins within the α phase contribute to the plastic strengthening of Cu-Zn-An-Al alloy, resulting in the strain-rate-hardening effect. As the deformation temperature increases, the shapes of the stress-strain curves are mainly influenced by the temperature-softening effect and the dynamic recrystallization of the α phase. Finally, material constants regarding the strain-rate-hardening and temperature-softening effects are determined, based on the Johnson-Cook constitutive model. The results show that compared with other metallic materials, the present Cu-Zn-Sn-Al alloy has a relatively stronger strain-rate-hardening effect and weaker temperature-softening effect.

Dynamic finite element simulation of wheel–rail contact response for the straight track case

2020 ◽  
pp. 136943322097173
Author(s):  
Xiongfei Zhou ◽  
Lin Jing ◽  
Xiaoqi Ma
Keyword(s):  
Finite Element ◽  
Strain Rate ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Rolling Contact ◽  
Inertia Effect ◽  
Hardening Effect ◽  
Train Speed ◽  
Strain Rate Hardening ◽  
Contact Response

The dynamic effects, mainly including the inertia effect and strain-rate effect, on the dynamic wheel–rail contact behavior become more and more serious as the train speed increases. The inertia effect can be automatically taken into account in explicit finite element analysis codes, while the strain-rate effect needs to be considered via inputting the related material parameters. In the present paper, the influence of strain rate on the dynamic wheel–rail contact response for the straight track case was explored, based on a 3D wheel–rail rolling contact finite element model, via LS-DYNA/explicit algorithm. Effects of the axle load and train speed on typical dynamic wheel–rail responses were discussed, and the results indicate that the coupled train speed with strain rate has a non-negligible influence on dynamic contact responses. The strain rate hardening effect increases the maximum contact pressure and stress, and inhibits the plastic deformation of the wheel–rail system. A rate-sensitive factor (RSF) was then introduced to describe the strain rate hardening effect, confirming that the rail is more sensitive to strain rate compared to the wheel. Finally, an error analysis of the wheel–rail Hertz contact theory was conducted, which further verify the differences between elastic and elastic-plastic contact solutions.

Study on Dynamic Mechanical Response of TC21 Alloy

2011 ◽  
Vol 88-89 ◽  
pp. 674-678
Author(s):  
Shuang Zan Zhao ◽  
Xing Wang Cheng ◽  
Fu Chi Wang
Keyword(s):  
Flow Stress ◽  
High Strain Rate ◽  
Strain Rate ◽  
Strain Hardening ◽  
High Strain ◽  
Dynamic Flow ◽  
Dynamic Mechanical ◽  
Hardening Effect ◽  
High Strain Rate Deformation ◽  
Binary Morphology

Some results of an experimental study on high strain rate deformation of TC21 alloy are discussed in this paper. Cylindrical specimens of the TC21 alloys both in binary morphology and solution and aging morphology were subjected to high strain rate deformation by direct impact using a Split Hopkinson Pressure Bar. The deformation process is dominated by both thermal softening effect and strain hardening effect under high strain rate loading. Thus the flow stress doesn’t increase with strain rate at the strain hardening stage, while the increase is obvious under qusi-static compression. Under high strain rate, the dynamic flow stress is higher than that under quasi-static and dynamic flow stress increase with the increase of the strain rate, which indicates the strain rate hardening effect is great in TC21 alloy. The microstructure affects the dynamic mechanical properties of TC21 titanium alloy obviously. Under high strain rate, the solution and aging morphology has higher dynamic flow stress while the binary morphology has better plasticity and less prone to be instability under high strain rate condition. Shear bands were found both in the solution and aging morphology and the binary morphology.

Numerical Analysis of Plane-Strain Tension Test for Rate-Dependent Solids

1992 ◽  
Vol 59 (3) ◽  
pp. 485-490 ◽  
Author(s):  
P. Tugˇcu
Keyword(s):  
Numerical Analysis ◽  
Strain Rate ◽  
Plane Strain ◽  
Rate Sensitivity ◽  
Tension Test ◽  
Engineering Strain ◽  
Plane Strain Tension ◽  
Rate Dependent ◽  
Strain And Strain Rate ◽  
Strain Rate Hardening

The plane-strain tension test is analyzed numerically for a material with strain and strain-rate hardening characteristics. The effect of the prescribed rate of straining is investigated for an additive logarithmic description of the material strain-rate sensitivity. The dependency to the imposed strain rate so introduced is shown to have a significant effect on several features of the load-elongation curve such as the attainment of the load maximum, the onset of localization, and the overall engineering strain.

LOAD-CARRYING CAPACITIES FOR CIRCULAR METAL FOAM CORE SANDWICH PANELS AT LARGE DEFLECTION

2008 ◽  
Vol 22 (31n32) ◽  
pp. 6218-6223 ◽  
Author(s):  
W. HOU ◽  
Z. WANG ◽  
L. ZHAO ◽  
G. LU ◽  
D. SHU
Keyword(s):  
Finite Element ◽  
Velocity Field ◽  
Large Deflection ◽  
Metal Foam ◽  
Yield Criterion ◽  
Metallic Foam ◽  
Foam Core ◽  
Element Simulation ◽  
Load Carrying ◽  
Good Agreement

This paper is concerned with the load-carrying capacities of a circular sandwich panel with metallic foam core subjected to quasi-static pressure loading. The analysis is performed with a newly developed yield criterion for the sandwich cross section. The large deflection response is estimated by assuming a velocity field, which is defined based on the initial velocity field and the boundary condition. A finite element simulation has been performed to validate the analytical solution for the simply supported cases. Good agreement is found between the theoretical and finite element predictions for the load-deflection response.

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