Using Hopkinson pressure bar to perform dynamic tensile tests on SFRC at medium strain rates

2012 ◽  
Vol 64 (8) ◽  
pp. 657-664 ◽  
Author(s):  
Zhiliang Wang ◽  
Nianqing Zhou ◽  
Jianguo Wang
2018 ◽  
Vol 183 ◽  
pp. 01058 ◽  
Author(s):  
Philip Church ◽  
Mark Reynolds ◽  
Peter Gould ◽  
Robin Oakley ◽  
Nigel Harrison ◽  
...  

Additively Manufactured (AM) materials have great potential for producing graded materials, embedded structures and near net complex shapes. AM maraging steel properties have been compared with wrought maraging steel. The comparison featured interrupted tensile tests over a range of temperatures and strain rates. In addition a specially designed Tensile Split Hopkinson Pressure Bar (TSHPB) has been built to test very high strength metals at high strain rates. The results showed that the AM maraging steel was much more ductile than expected and exhibited significant necking under all conditions tested. All the samples exhibited ductile fracture. Although not as ductile as the wrought material, the AM material could be cost effective through economies of scale for complex components. The microstructure contained inclusions which derived from either the powder or the AM process and thus there is significant potential to improve these materials further. A modified Armstrong-Zerilli model was also constructed for these materials and shown to predict the raw experimental data within experimental error using DYNA3D simulations.


2014 ◽  
Vol 566 ◽  
pp. 158-163 ◽  
Author(s):  
A. Yosimoto ◽  
Hidetoshi Kobayashi ◽  
Keitaro Horikawa ◽  
Keiko Watanabe ◽  
Kinya Ogawa

In order to clarify the effect of strain rate and test temperature on the compressive strength and energy absorption of polyimide foam, a series of compression tests for the polyimide foam with two different densities were carried out. By using three testing devices, i.e. universal testing machine, dropping weight machine and sprit Hopkinson pressure bar apparatus, we performed a series of compression tests at various strain rates (10-3~103s-1) and at several test temperatures in the range of room temperature to 280 ̊C. At over 100 s-1, the remarkable increase of flow stress was observed. The negative temperature dependence of strength was also observed.


2018 ◽  
Vol 183 ◽  
pp. 04005 ◽  
Author(s):  
Bar Nurel ◽  
Moshe Nahmany ◽  
Adin Stern ◽  
Nahum Frage ◽  
Oren Sadot

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.


2013 ◽  
Vol 718-720 ◽  
pp. 112-116
Author(s):  
Xu Yang Li ◽  
Rui Yuan Huang ◽  
Yong Chi Li ◽  
Guang Fa Gao

The Split Hopkinson Pressure Bar (SHPB) is used to investigate the dynamic compressive mechanical behavior of a new foamed ceramic composite under impact loading. The stress versus strain curves are obtained under high strain rates. The test results are considered to be able to assure conformability of the tests, validate the stress equilibrium assumption, and show that the stress versus strain curves of foamed ceramic composite display strain hardening effect and damage softening effect as brittle materials. Meanwhile the curve includes short plateau region while no densification region.


2013 ◽  
Vol 631-632 ◽  
pp. 458-462 ◽  
Author(s):  
Peng Duo Zhao ◽  
Yu Wang ◽  
Jian Ye Du ◽  
Lei Zhang ◽  
Zhi Peng Du ◽  
...  

The strain rate sensitivity of neoprene is characterized using a modified split Hopkinson pressure bar (SHPB) system at intermediate (50 s-1, 100 s-1) and high (500 s-1, 1000 s-1) strain rates. We used two quartz piezoelectric force transducers that were sandwiched between the specimen and experimental bars respectively to directly measure the weak wave signals. A laser gap gage was employed to monitor the deformation of the sample directly. Three kinds of neoprene rubbers (Shore hardness: SHA60, SHA65, and SHA70) were tested using the modified split Hopkinson pressure bar. Experimental results show that the modified apparatus is effective and reliable for determining the compressive stress-strain responses of neoprene at intermediate and high strain rates.


2006 ◽  
Vol 306-308 ◽  
pp. 905-910 ◽  
Author(s):  
Zhi Hua Wang ◽  
Hong Wei Ma ◽  
Long Mao Zhao ◽  
Gui Tong Yang

The compressive deformation behavior of open-cell aluminum foams with different densities and morphologies was assessed under quasi-static and dynamic loading conditions. High strain rate experiments were conducted using a split Hopkinson pressure bar technique at strain rates ranging from 500 to 1 2000 − s . The experimental results shown that the compressive stress-strain curves of aluminum foams also have the “ three regions” character appeared in general foam materials, namely elastic region, collapse region and densification regions. It is found that density is the primary variable characterizing the modulus and yield strength of foams and the cell appears to have a negligible effect on the strength of foams. It also is found that yield strength and energy absorption is almost insensitive to strain rate and deformation is spatially uniform for the open-celled aluminum foams, over a wide range of strain rates.


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