Construction of Johnson-Cook Model for Gr2 Titanium through Adiabatic Heating Calculation

2014 ◽  
Vol 487 ◽  
pp. 7-14 ◽  
Author(s):  
Xi Guang Deng ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Xiao Yun Song

This study derived the five parameters in Johnson-Cook equation of CP titanium Gr2. Quasi-static and dynamic compression tests were designed to measure mechanical properties at strain rates of 10-3s-1 and 6000s-1. In order to secure the validity of tested data, a novel fixture was proposed to reduce the displacement measurement error in MTS testing system and the signal processing procedure of compressive split Hopkinson pressure bar for the present study was demonstrated. With the tested data and calculated adiabatic heating temperature rise, parameters A, B, n, m, C have been derived based on mathematical deduction and solve. It was found that the constructed constitutive model fit the tested data well and was able to restore the yield strength value at high strain rate.

2014 ◽  
Vol 566 ◽  
pp. 122-127
Author(s):  
Takayuki Kusaka ◽  
Takanori Kono ◽  
Yasutoshi Nomura ◽  
Hiroki Wakabayashi

A novel experimental method was proposed for characterizing the compressive properties of composite materials under impact loading. Split Hopkinson pressure bar system was employed to carry out the dynamic compression tests. The dynamic stress-strain relations could be precisely estimated by the proposed method, where the ramped input, generated by the plastic deformation of a zinc buffer, was effective to reduce the oscillation of the stress field in the specimen. The longitudinal strain of gage area could be estimated from the nominal deformation of gage area, and consequently the failure process could be grasped in detail from the stress-strain relation. The dynamic compressive strength of the material was slightly higher than the static compressive strength. In addition, the validity of the proposed method was confirmed by the computational and experimental results.


2012 ◽  
Vol 450-451 ◽  
pp. 523-526 ◽  
Author(s):  
Hai Feng Liu ◽  
Wei Wu Yang ◽  
Jian Guo Ning

The dynamic compression tests of reinforced concrete with different reinforcement ratios are carried out by split Hopkinson pressure bar (SHPB). Reinforced steel bar is placed along longitudinal and transverse direction. Experimental results show that reinforced concrete is non-linear and rate-dependent. With the enhancement of strain rate, the peak stress of reinforced concrete increases correspondingly


2021 ◽  
Vol 250 ◽  
pp. 03006
Author(s):  
Remigiusz Błoniarz ◽  
Janusz Majta ◽  
Carl P. Trujillo ◽  
Ellen K. Cerreta ◽  
Krzysztof Muszka

In the presented work two grades of steel i.e. microalloyed ferrite (M_F) and microalloyed austenite (M_A) where subjected to the grain refinement processes using MaxStrain system and thermomechanical rolling. The wide range of grain size, starting from 200 µm down to submicrometer level was produced in this way. The specimens of both steels were subjected to the dynamic compression tests using the Split Hopkinson Pressure Bar (SHPB) apparatus and applying the strain rates in the range between ε˙ = 3750s-1 and ε˙ = 6000s-1. In addition, different temperatures were used in the tests, i.e.200 °C and 400 °C. The first peak of stress which is observed during elastic-plastic transition during the dynamic compression tests can be treated as a characteristic feature of the tested material. The results obtained in the present investigations showed a significant dependence of the “first stress peak” in the dynamic compression curve on the degree of the microstructure refinement for the samples of M_F and almost complete absence of this dependence for M_A.


2013 ◽  
Vol 442 ◽  
pp. 125-128
Author(s):  
Wen Jun Hu ◽  
Xi Cheng Huang ◽  
Fang Ju Zhang ◽  
Yong Mei Chen

Strain rate response of polycarbonate was investigated under uniaxial compression at different rates of strain ranging from 0.0001/sec to about 8200/sec and different temperature ranging from 145k to about 423k. A split Hopkinson pressure bar was used to determine the dynamic compressive responses. A pulse-shaping technique was employed in dynamic compression experiment to ensure that valid experimental conditions were satisfied. Results show that, compared with quasi-static behavior, dynamic compression results in significantly higher compressive strengths for polycarbonate materials.


Author(s):  
Xia Zhengbing ◽  
Zhang Kefeng ◽  
Deng Yanfeng ◽  
Ge Fuwen

Recently, engineering blasting is widely applied in projects such as rock mineral mining, construction of underground cavities and field-leveling excavation. Dynamic mechanical performance of rocks has been gradually attached importance both in China and abroad. Concrete and rock are two kinds of the most frequently used engineering materials and also frequently used as experimental objects currently. To compare dynamic mechanical performance of these two materials, this study performed dynamic compression test with five different strain rates on concrete and rock using Split Hopkinson Pressure Bar (SHPB) to obtain basic dynamic mechanical parameters of them and then summarized the relationship of dynamic compressive strength, peak strain and strain rate of two materials. Moreover, specific energy absorption is introduced to confirm dynamic damage mechanisms of concrete and rock materials. This work can not only help to improve working efficiency to the largest extent but also ensure the smooth development of engineering, providing rich theoretical guidance for development of related engineering in the future.


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 326-328 ◽  
pp. 1573-1576
Author(s):  
Dong Feng Cao ◽  
Li Sheng Liu ◽  
Jiang Tao Zhang

Dynamic response and fracture of high strength boride/alumina ceramic composite were investigated by split Hopkinson pressure bar (SHPB) experiment in this paper. The compressive stress–strain curves and dynamic compression strength of the composites were tested. The surface’s microstructure of fractured composites were examined by using scanning electron microscope (SEM) to investigate the fracture mechanism. The results show that boride/alumina has high dynamic compressive strength and high Young’s modulus. The main fracture mode of the material is the fracture of the ceramic grains. The micro-voids and flaws, generated during the sintering and manufacturing of material and mechanical process of specimen, decrease the strength of the material because they provide the source of crack expansion when the material undergoes the dynamic loadings.


2019 ◽  
Vol 55 (1) ◽  
pp. 129-134
Author(s):  
P. Jozwik ◽  
M. Kopec ◽  
W. Polkowski ◽  
Z. Bojar

In this work, the Ni3Al-based intermetallic alloy was subjected to room temperature dynamic plastic deformation tests by using a split Hopkinson pressure bar technique. The dynamic compression processes were carried out at strain rates in the range of =(1.9x102 / 1x104 s-1). A strong impact of applied deformation conditions on microstructure and mechanical properties evolution in the examined Ni3Al intermetallic, was documented. Generally, very high maximum compressive stress values were obtained, reaching 5500 MPa for the sample deformed at the highest strain rate (i.e. ??=1x104 s-1). The results of performed SEM/EBSD evaluation point towards an occurrence of dynamic recovery and recrystallization phenomena in Ni3Al samples deformed at high strain rates.


2020 ◽  
Vol 999 ◽  
pp. 83-90
Author(s):  
Xiao Ju Gao ◽  
Hasigaowa ◽  
Meng Yong Sun ◽  
Cheng Dong Liao ◽  
Wei Ping Huang ◽  
...  

SiC/B4C composite was obtained using the reaction sintering method with Si infiltration, which exhibited excellent mechanical properties. The dynamic compressive response was investigated using a Split Hopkinson pressure bar at high strain rates ranging from 0.4×103 to 1.2×103 s-1. The results show that the dynamic strength of the SiC/B4C composite obtains a peak value at a strain rate of 1000/s, while its strain increased continuously with increasing strain rate. The dynamic loading mode of SiC/B4C composite exhibited three deformation regions, including an inelastic deformation region, rapid loading region and failure region. The dynamic failure mode of SiC/B4C composite depended upon the strain rate.


2014 ◽  
Vol 584-586 ◽  
pp. 1089-1096
Author(s):  
Remdane Boutemeur ◽  
Mustapha Demidem ◽  
Abderrahim Bali ◽  
El Hadi Benyoussef

The aim of this study is to present a model for assessing the dynamic compression behaviour of a micro-concrete. This model is based on the results of numerous tests providing the developments of the mechanical characteristics of the material on a wide range of strain rate from 10-4s-1to 10+3s-1.The Split Hopkinson Pressure Bar (SHPB) dispositive, based on the wave propagation theory in materials, has-been adopted to carry out the dynamic tests on the investigated material. The proposed model is composed of two terms, each characterizing the different contributions noted in the two major explored areas of strain rate.


Sign in / Sign up

Export Citation Format

Share Document