102 Dynamic deformation behavior of rubber under high strain rate compressive loading

The dynamic deformation behavior of an as-extruded Mg-Gd-Y magnesium alloy was studied by using Split Hopkinson Pressure Bar (SHPB) apparatus under high strain rates of 102 s-1 to 103s-1 in the present work, in the mean while the microstructure evolution after deformation were inspected by OM and SEM. The results demonstrated that the material is not sensitive to the strain rate and with increasing the strain rate the yield stress of as-extruded Mg-Gd-Y magnesium alloy has a tendency of increasing. The microstructure observation results shown that several deformation localization areas with the width of 10mm formed in the strain rates of 465s-1 and 2140s-1 along the compression axis respectively, and the grain boundaries within the deformation localization area are parallel with each other and are perpendicular to the compression axis. While increasing the strain rate to 3767s-1 the deformation seems become uniform and all the grains are compressed flat in somewhat. The deformation mechanism of as-extruded Mg-Gd-Y magnesium alloy under high strain rate at room temperature was also discussed.

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Influence of Temperature and Heat-Aged Condition on the Deformation Behavior of Rubber Material Using SHPB Technique with a Pulse Shaper

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.619 ◽

2007 ◽

Vol 353-358 ◽

pp. 619-626

Author(s):

Ouk Sub Lee ◽

Yong Hwan Han ◽

Dong Hyeok Kim

Keyword(s):

High Strain Rate ◽

Strain Rate ◽

Deformation Behavior ◽

High Strain ◽

Dynamic Deformation ◽

Material Behavior ◽

Pulse Shaper ◽

Rubber Material ◽

Experimental Apparatus ◽

Pressure Bar

The Split Hopkinson Pressure Bar (SHPB) technique with some special experimental apparatus can be used to obtain the dynamic material behavior under high strain rate loading conditions. An experimental technique that modifies the conventional SHPB has been developed for measuring the compressive stress strain responses of materials with low mechanical impedance and low compressive strengths such as rubber. This paper uses PEEK (Poly-ether-ether-ketone plastic) bars to achieve a closer impedance match between the pressure bar and the specimen materials. In addition, a pulse shaper is utilized to lengthen the rise time of the incident pulse to ensure stress equilibrium and homogeneous deformation of the rubber specimen. It is confirmed that the modified technique is useful to record the dynamic deformation behavior of rubbers under various conditions such as high strain rate with various temperature effect. Furthermore, the dynamic deformation behaviors of heat-aged rubber material under compressive high strain rate are evaluated using the modified SHPB technique.

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Dynamic Deformation Behavior of Rubber under High Strain Rate Compressive Loading

International Journal of Modern Physics B ◽

10.1142/s0217979203019083 ◽

2003 ◽

Vol 17 (08n09) ◽

pp. 1415-1420 ◽

Cited By ~ 6

Author(s):

Ouk Sub Lee ◽

Myun Soo Kim ◽

Kyoung Joon Kim ◽

Si Won Hwang ◽

Kyu Sang Cho

Keyword(s):

Strain Rate ◽

Deformation Behavior ◽

Split Hopkinson Pressure Bar ◽

Dynamic Deformation ◽

Compressive Loading ◽

Hopkinson Pressure Bar ◽

Split Hopkinson ◽

Transition Points ◽

Dynamic Deformation Behavior ◽

Pressure Bar

A specific experimental method, the split Hopkinson pressure bar (SHPB) technique is used to determine the dynamic material properties under the impact compressive loading condition with strain-rate of the order of 103/s~104/s. The dynamic deformation behavior of rubber materials widely used for the isolation of vibration from varying structures under dynamic loading is determined by using the Split Hopkinson Pressure Bar technique. The relationships between the stresses at transition points of rubber materials and the strain rate are found to be bilinear. However, an interesting relationship between the strains at transition points of rubber materials and the strain rate, which needs further investigation, is noted.

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Research on Numerical Algorithm of Constitutive Equation under High Speed Deformation in Hadfield Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.562-564.688 ◽

2012 ◽

Vol 562-564 ◽

pp. 688-692 ◽

Cited By ~ 1

Author(s):

Deng Yue Sun ◽

Jing Li ◽

Fu Cheng Zhang ◽

Feng Chao Liu ◽

Ming Zhang

Keyword(s):

High Strain Rate ◽

Strain Rate ◽

Deformation Behavior ◽

High Speed ◽

High Strain ◽

Equivalent Stress ◽

Hadfield Steel ◽

Stress And Strain ◽

Strain Rates ◽

The Finite Element Method

The influence of the strain rate on the plastic deformation of the metals was significant during the high strain rate of loading. However, it was very difficult to obtain high strain rate data (≥ 104 s-1) by experimental techniques. Therefore, the finite element method and iterative method were employed in this study. Numerical simulation was used to characterise the deformation behavior of Hadfield steel during explosion treatment. Base on experimental data, a modified Johnson-Cook equation for Hadfield steel under various strain rate was fitted. The development of two field variables was quantified during explosion hardening: equivalent stress and strain rates.

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Study on Plastic Deformation Behavior of Mo-10Ta under Ultra-High Strain Rate

Metals ◽

10.3390/met10091153 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1153

Author(s):

Ping Song ◽

Wen-Bin Li ◽

Yu Zheng ◽

Jiu-Peng Song ◽

Xiang-Cao Jiang ◽

...

Keyword(s):

Activation Energy ◽

High Strain Rate ◽

Strain Rate ◽

Strain Rate Sensitivity ◽

Deformation Behavior ◽

High Strain ◽

Rate Sensitivity ◽

Strain Rate Range ◽

Rate Range ◽

Strain Relationship

This study investigated the deformation behavior of the Mo-10Ta alloy with a strain rate range of 102–105 s−1. The Split Hopkinson pressure bar (SHPB) experiments were conducted to investigate the influence of deformation conditions on the stress-strain relationship and strain rate sensitivity of the material within a strain rate range of 0.001–4500 s−1. The Shaped Charge Jet (SCJ) forming experiments under detonation loading was conducted to clarify the dynamic response and microstructure evolution of the material within an ultra-high strain rates range of 104–105 s−1. Based on the stress-strain relationship of Mo-10Ta alloy at high temperature (286–873 K) and high strain rate (460–4500 s−1), the influence of temperature and strain rate on the activation energy Q was analyzed. The results indicate that the material strain rate sensitivity increased with the increase in strain rate and strain. Meanwhile, the activation energy Q decreased as the temperature and strain rate increased. The plasticity of the Mo-10Ta alloy under the condition of SCJ forming was substantially enhanced compared with that under quasi-static deformation. The material grain was also refined under ultra-high strain rate, as reflected by the reduction in grain size from 232 μm to less than 10 μm.

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