scholarly journals The Image-Based Inertial Release (IBIR) Test: A New High Strain Rate Test for Stiffness Strain-Rate Sensitivity Identification

2020 ◽  
Vol 60 (4) ◽  
pp. 493-508 ◽  
Author(s):  
L. Fletcher ◽  
F. Pierron
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
High Strain ◽  
Rate Sensitivity ◽  
Rate Test ◽  
High Strain Rate Test

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

Metals ◽  
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.

High Strain Rate Compressive Behaviour of Selective Laser Melted Ti-6Al-4V

2017 ◽  
Vol 890 ◽  
pp. 323-326 ◽  
Author(s):  
Maziar Ramezani ◽  
Emmanuel Flores-Johnson ◽  
Lu Ming Shen ◽  
Thomas Neitzert
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Shear Failure ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Rate Sensitivity ◽  
Melting Process ◽  
Mechanical Tests ◽  
Hopkinson Pressure Bar

Ti-6Al-4V alloy is one of the most important engineering alloys, combining attractive properties with inherent workability. The aim of this study is to investigate the effect of strain rate on the compressive mechanical properties of Ti6Al4V alloy manufactured by a selective laser melting process. The mechanical tests were performed by means of a compression split Hopkinson pressure bar apparatus under high strain rate ranging from 1400 s-1 to 4500 s-1. The true stress-strain curves obtained from static and dynamic compressive tests show strain rate sensitivity from quasi-static (peak strength 1300MPa) to high strain rate (peak 1500 MPa). Within the high strain rate range tested, the strain rate sensitivity is not remarkable. The fractographic analysis shows a relatively smooth and smeared fractured surface along with a dimple like structure. The observation of elongated dimples confirms the operation of a dynamic shear failure mechanism for the additively manufactured Ti-6Al-4V parts.

scholarly journals High strain rate in situ micropillar compression of a Zr-based metallic glass

2021 ◽  
Author(s):  
Rajaprakash Ramachandramoorthy ◽  
Fan Yang ◽  
Daniele Casari ◽  
Moritz Stolpe ◽  
Manish Jain ◽  
...  
Keyword(s):  
Metallic Glass ◽  
High Strain Rate ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
High Strain ◽  
Deformation Behaviour ◽  
Rate Sensitivity ◽  
Propagation Speed ◽  
Atomic Scale ◽  
Complex Deformation

Abstract High strain rate micromechanical testing can assist researchers in elucidating complex deformation mechanisms in advanced material systems. In this work, the interactions of atomic-scale chemistry and strain rate in affecting the deformation response of a Zr-based metallic glass was studied by varying the concentration of oxygen dissolved into the local structure. Compression of micropillars over six decades of strain rate uncovered a remarkable reversal of the strain rate sensitivity from negative to positive above ~ 5 s−1 due to a delocalisation of shear transformation events within the pre-yield linear regime for both samples, while a higher oxygen content was found to generally decrease the strain rate sensitivity effect. It was also identified that the shear band propagation speed increases with the actuation speed, leading to a transition in the deformation behaviour from serrated to apparent non-serrated plastic flow at ~ 5 s−1. Graphic abstract

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