Improved Pulse Shaping to Achieve Constant Strain Rate and Stress Equilibrium in Split-Hopkinson Pressure Bar Testing

2007 ◽  
Vol 38 (11) ◽  
pp. 2655-2665 ◽  
Author(s):  
Kenneth S. Vecchio ◽  
Fengchun Jiang
Keyword(s):  
Strain Rate ◽  
Pulse Shaping ◽  
Split Hopkinson Pressure Bar ◽  
Constant Strain Rate ◽  
Hopkinson Pressure Bar ◽  
Stress Equilibrium ◽  
Split Hopkinson ◽  
Pressure Bar

Testing Techniques to Eliminate Frictional Effect and to Achieve Constant Strain-Rate in Split Hopkinson Pressure Bar Impact Compression System

2011 ◽  
Vol 673 ◽  
pp. 77-82
Author(s):  
Minoru Yamashita ◽  
Mitsuru Suganuma ◽  
Yasuhisa Sato
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Constant Strain Rate ◽  
Intrinsic Stress ◽  
Hopkinson Pressure Bar ◽  
Impact Compression ◽  
Compression System ◽  
Frictional Effect ◽  
Split Hopkinson ◽  
Pressure Bar

In order to obtain the intrinsic stress – strain relationship by split Hopkinson pressure bar (SHPB) impact compression system, two testing techniques to eliminate the frictional effect and hold the prescribed constant strain-rate are demonstrated. The extrapolation method eliminating frictional effect at the tool – specimen interface was exhibited. Several specimens with different height were used for changing the initial diameter / height ratio in the method, where the circular plates were laminated. In order to maintain the constant strain-rate during compression, the incident pulse was adjusted to elevate in accordance with the compression force, where the tapered cylindrical striker bar was applied. Test material is a fully annealed pure aluminum. The intrinsic stress – strain relationship at strain-rate of 1000 /s was determined and the strain-rate sensitivity was also determined. The numerical simulation of the SHPB impact compression system was also performed using the dynamic explicit finite element method. The additional evidence for these experimental techniques to accomplish the elimination of friction and the constant strain-rate was shown.

Dynamic Compressive Behavior of Granite under Active Confinement

2011 ◽  
Vol 291-294 ◽  
pp. 1227-1232 ◽  
Author(s):  
Gang Chen ◽  
Yu Chun Kuang ◽  
Xi Cheng Huang ◽  
Ai Min Xu
Keyword(s):  
Strain Rate ◽  
Pulse Shaping ◽  
Split Hopkinson Pressure Bar ◽  
Hopkinson Pressure Bar ◽  
Pulse Shaper ◽  
Safety Requirements ◽  
Split Hopkinson ◽  
Active Confinement ◽  
Pressure Bar ◽  
Stress Uniformity

The behaviour of geologic material such as granite under impact loading is involved in the study of safety requirements of structures in extreme simulations such as earthquakes, accidental impacts or explosions. Based on incident pulse shaping design of quasi-brittle material for dynamic tests, experiments on granite under uniaxial and active confinement conditions are conducted with the split Hopkinson pressure bar(SHPB). By adding the soft material mass as the pulse shaper, the stress uniformity in the specimens before fracture is ensured and the fluctuation of test data due to incident stress pulse is avoid. The experimental results show that the compressive strength is increasing with the strain rate and the confined pressure. The fragments size decreases with the strain rate. The research method and conclusion could be used to analyze the dynamic behavior of the other brittle materials.

Dynamic Behaviors of near β-Type Ti-5Al-5Mo-5V-3Cr Titanium Alloys under High Strain Rate

2015 ◽  
Vol 816 ◽  
pp. 795-803
Author(s):  
Yan Ling Wang ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Rui Liu
Keyword(s):  
Strain Rate ◽  
Titanium Alloys ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Failure Behavior ◽  
Hopkinson Pressure Bar ◽  
Fracture Failure ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Dynamic Loading Conditions

The mechanical properties and fracture failure behavior of the near β-type Ti-5Al-5Mo-5V-3Cr-X (X = 1Fe or 1Zr) titanium alloys were studied by Split Hopkinson Pressure Bar (SHPB) experiment under the dynamic loading conditions at a strain rate of 1.5 × 103 s-1–5.0 × 103 s-1. Results showed that the SHPB specimen fractured in the direction of maximum shearing stress at an angle of 45° with the compression axis. The fracture surface revealed the shear and tension zones with cleavage steps and parabolic dimples. Severe early unloading was observed on the Ti-5553 alloy under a strain rate of 4,900 s-1 loading condition, and the dynamic property of the Ti-55531Zr alloy was proved to be the optimal.

Dynamic Hardness of MCrAlY Abradable Seal Coating

2021 ◽  
Vol 1035 ◽  
pp. 591-595
Author(s):  
Dan Guo ◽  
Jian Ming Liu ◽  
De Ming Zhang ◽  
Xin Zhang ◽  
Tong Liu
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Hopkinson Pressure Bar ◽  
Dynamic Hardness ◽  
Mcraly Coating ◽  
Static Hardness ◽  
Split Hopkinson ◽  
The Difference ◽  
Pressure Bar ◽  
Abradable Coatings

The purpose of this investigation is to study the dynamic hardness of MCrAlY abradable coatings under different strain rates. A dynamic indentation device based on the split Hopkinson pressure bar system (SHPB) was used. The results show that the hardness of MCrAlY coating increased with the increase of the strain rate, which has a positive strain rate effect. In addition, the difference of the static hardness of MCrAlY coating prepared by HVOF and LPPS was only 4%, while the difference in dynamic hardness was 16%.

scholarly journals Study on the dynamic properties of AM-SLM AlSi10Mg alloy using the Split Hopkinson Pressure Bar (SHPB) technique

2018 ◽  
Vol 183 ◽  
pp. 04005 ◽  
Author(s):  
Bar Nurel ◽  
Moshe Nahmany ◽  
Adin Stern ◽  
Nahum Frage ◽  
Oren Sadot
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Static Mechanical ◽  
Split Hopkinson ◽  
Pressure Bar

Additive manufacturing by Selective Laser Melting of metals is attracting substantial attention, due to its advantages, such as short-time production of customized structures. This technique is useful for building complex components using a metallic pre-alloyed powder. One of the most used materials in AMSLM is AlSi10Mg powder. Additively manufactured AlSi10Mg may be used as a structural material and it static mechanical properties were widely investigated. Properties in the strain rates of 5×102–1.6×103 s-1 and at higher strain rates of 5×103 –105 s-1 have been also reported. The aim of this study is investigation of dynamic properties in the 7×102–8×103 s-1 strain rate range, using the split Hopkinson pressure bar technique. It was found that the dynamic properties at strain-rates of 1×103–3×103 s-1 depend on a build direction and affected by heat treatment. At higher and lower strain-rates the effect of build direction is limited. The anisotropic nature of the material was determined by the ellipticity of samples after the SHPB test. No strain rate sensitivity was observed.

Sign in / Sign up

Export Citation Format

Share Document