The Sensitivity of Strain Rate and Size Effect with Different Particle Volume Fraction in SiCp/Al Composite

2009 ◽  
Vol 631-632 ◽  
pp. 513-518 ◽  
Author(s):  
Dong Feng Cao ◽  
Li Sheng Liu ◽  
Hai Mei ◽  
Qing Jie Zhang
Keyword(s):  
Size Effect ◽  
Strain Rate ◽  
Volume Fraction ◽  
Split Hopkinson Pressure Bar ◽  
Particle Volume Fraction ◽  
Testing Machine ◽  
Hopkinson Pressure Bar ◽  
Particle Volume ◽  
Al Composite ◽  
Universal Material Testing Machine

In this paper the sensitivity of strain rate and size effect with different particle volume fraction in SiCp/Al Composite were studied through the experiment. Specimens with 40% and 30% SiC particle volume fraction were made. There are three types of particle sizes in each volume fraction. The sensitivity of strain rate and the effect of particle size in Al matrix composites reinforced with the different volume fraction were investigated, using the split Hopkinson pressure bar and Instron5882 universal material testing machine. The surface microstructure of the specimens in each composite was examined using optical microscopy and SEM. Through the strain-stress curves, the sensitivity of strain rate can be obtained. The experimental results show that the sensitivity of strain rate increases with the increasing of particle volume fraction. At the same volume fraction, the size effect were observed obviously and higher flow stresses were obtained in the composites reinforced with small particles than that in the composite with large particles.

EFFECT OF MICROSTRUCTURES ON THE DYNAMIC DEFORMATION BEHAVIOR OF Ti-6Al-4V ALLOY

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1221-1227
Author(s):  
JIN-YOUNG KIM ◽  
IN-OK SHIM ◽  
SOON-HYUNG HONG
Keyword(s):  
Strain Rate ◽  
Strain Hardening ◽  
Volume Fraction ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Deformation ◽  
Testing Machine ◽  
Hydraulic Testing ◽  
Deformation Condition ◽  
Strain Hardening Exponent ◽  
Hopkinson Pressure Bar

The effects of microstructures of Ti -6 Al -4 V alloy on the flow stresses and fracture behaviors at quasi-static and dynamic deformation conditions were investigated. Specimens of different sizes and fractions of α globules in equiaxed and bimodal structures were compressed at the strain rate of 2×10−3/ s and 3×103/ s using hydraulic testing machine and split Hopkinson pressure bar, respectively. The a globule size in equiaxed structure changed the level of flow stresses, but did not affect the strain hardening characteristics. Meanwhile, the volume fraction of α globule (or lamellar phase) in bimodal structures influenced both the flow stress and strain hardening exponent at quasi-static and dynamic deformation conditions. Bimodal structure of 50% lamellar fraction is considered to be more favorable in dynamic deformation condition at strain rate regime of 3×103/ s than equiaxed or bimodal one having higher lamellar fraction.

Size Effect Analysis during Material Deformation with High Strain Rate

2013 ◽  
Vol 589-590 ◽  
pp. 198-203
Author(s):  
Feng Jiang ◽  
Lan Yan ◽  
Zhong Wei Hu ◽  
Yi Ming(Kevin) Rong
Keyword(s):  
Shear Stress ◽  
Size Effect ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Failure Strain ◽  
Testing Machine ◽  
Hopkinson Pressure Bar ◽  
Dynamic Impact ◽  
Impact Tests ◽  
Material Deformation

The goal of this study is to analyze the material deformation behavior in the micron level by quasi-static and dynamic impact tests of hat shaped specimen. Three type of specimen with different shear ring thicknesses (800μm, 400μm, 50μm) were designed. The quasi-static and dynamic impact tests were performed by electronic universal testing machine and split Hopkinson pressure bar (SHPB) respectively. During the material deformation in the SHPB test, the value scope of strain is 0 to 9 while the value scope of strain rate is 0.001s-1 to 400000s-1. The size effect phenomenon on shear stress and failure strain with different shear ring thickness was investigated. The shear stress and failure strain of material increases with the decrease of shear ring thickness. And the size effect phenomenon was weakened with the increase of strain rate.

scholarly journals High Strain-Rate Compressive Properties of Carbon/Epoxy Laminated Composites – Effects of loading direction and temperature

2018 ◽  
Vol 183 ◽  
pp. 02011
Author(s):  
Kenji Nakai ◽  
Tsubasa Fukushima ◽  
Takashi Yokoyama ◽  
Kazuo Arakawa
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Slenderness Ratio ◽  
Testing Machine ◽  
Negative Temperature ◽  
Hopkinson Pressure Bar ◽  
Instron Testing Machine

The high strain-rate compressive characteristics of a cross-ply carbon/epoxy laminated composite in the three principal material directions or fibre (1-), in-plane transverse (2-) and throughthickness (3-) directions are investigated on the conventional split Hopkinson pressure bar (SHPB) over a range of temperatures between 20 and 80 °C. A nearly 10 mm thick cross-ply carbon/epoxy composite laminate fabricated using vacuum assisted resin transfer molding (VaRTM) was tested. Cylindrical specimens with a slenderness ratio (= length/diameter) of 0.5 are used in high strain-rate tests, and those with the slenderness ratios of 1.0 and 1.5 are used in low and intermediate strain-rate tests. The uniaxial compressive stress-strain curves up to failure at quasi-static and intermediate strain rates are measured on an Instron testing machine at elevated temperatures. A pair of steel rings is attached to both ends of the cylindrical specimens to prevent premature end crushing in the 1-and 2-direction tests on the Instron testing machine. It is shown that the ultimate compressive strength (or failure stress) exhibits positive strainrate effects and negative temperature ones over a strain-rate range of 10–3 to 103/s and a temperature range of 20 to 80 °C in the three principal material directions.

Microstructures and Dynamic Compression Properties of a High Reinforcement Content TiB2/Al Composite

2007 ◽  
Vol 546-549 ◽  
pp. 639-642
Author(s):  
De Zhi Zhu ◽  
Gao Hui Wu ◽  
Long Tao Jiang ◽  
Guo Qin Chen
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Shear Fracture ◽  
Dynamic Compression ◽  
Average Particle Size ◽  
Average Particle ◽  
Hopkinson Pressure Bar ◽  
Compression Properties ◽  
Reinforcement Content ◽  
Al Composite

A high reinforcement content TiB2/2024Al composite with an average particle size of 8μm was fabricated by squeeze casting technology. The dynamic compression behaviors of the composite under varied strain rates were measured using split Hopkinson pressure bar, and its microstructure and fracture characteristic were examined. Resluts revealed that the composite was dense and homogenerous, and the TiB2-Al interface was clean without interfacial reactants. At high strain rate, the TiB2/Al composite showed insensitive to the strain rate, and both the flow stress and the elastic modulus improved little with an increase of the strain rate. The composite failed macroscopically in shear fracture and in split, which were caused by cracking of large reinforcement particles and interface failures under dynamic load.

Strain-Rate Relationship of Aluminum Matrix Composites Predicted by Johnson-Cook Model

2011 ◽  
Vol 704-705 ◽  
pp. 935-940
Author(s):  
De Zhi Zhu ◽  
Wei Ping Chen ◽  
Yuan Yuan Li
Keyword(s):  
Strain Rate ◽  
Volume Fraction ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Aluminum Matrix ◽  
Rate Sensitivity ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Hopkinson Pressure Bar ◽  
Cook Model

Strain-rate sensitivities of 55-65vol.% aluminum 2024-T6/TiB2composites and the corresponding aluminum 2024-T6 matrix were investigated using split Hopkinson pressure bar. Results showed that 55-65vol.% aluminum 2024-T6/TiB2composites exhibited significant strain-rate sensitivities, which were three times higher than that of the aluminum 2024-T6 matrix. The strain-rate sensitivity of the aluminum 2024-T6 matrix composites rose obviously with reinforcement content increasing (up to 60%), which agreed with the previous researches. The aluminum 2024-T6/TiB2composites showed hybrid fracture characteristics including particle cracking and aluminum alloy softening under dynamic loading. The flow stresses predicted by Johnson-Cook model increased slowly when the reinforcement volume fraction ranged in 10%-40%. While the reinforcement volume fraction was over 40%, the flow stresses of aluminum matrix composites increased obviously and the strains dropped sharply. Keywords: Composite materials; Dynamic compression; Stress-strain relationship

Study of the Microstructure of AZ31B Magnesium Alloy under High Strain Rate Deformation

2011 ◽  
Vol 686 ◽  
pp. 325-331 ◽  
Author(s):  
Ping Li Mao ◽  
Zheng Liu ◽  
Chang Yi Wang ◽  
Zhi Wang
Keyword(s):  
Magnesium Alloy ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Volume Fraction ◽  
Split Hopkinson Pressure Bar ◽  
Prismatic Slip ◽  
Hopkinson Pressure Bar ◽  
Az31b Magnesium Alloy ◽  
High Strain Rate Deformation

In order to investigate the microstructure evolution under high strain rate deformation of magnesium alloy, AZ31B magnesium alloy was impacted by Split Hopkinson Pressure Bar within the strain rates of 496s-1 to 2120s-1, then the specimens were observed by optical microscopy. The results show that when the strain rate are relatively low (496s-1-964s-1), the microstructure is predominated by high density of twinning, while increase the strain rate to 2120s-1 the volume fraction of twins is decreased. This implies that at relatively lower strain rate the deformation mechanism of AZ31B magnesium alloy under impact loading is twinning; increasing the strain rate the prismatic slip and pyramidal slip may be active besides twinning.

Effect of Foam Structure on Impact Compressive Properties in Foamed Polyethylene Film

2016 ◽  
Vol 715 ◽  
pp. 159-164 ◽  
Author(s):  
Kohei Tateyama ◽  
Hiroyuki Yamada ◽  
Nagahisa Ogasawara
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Polyethylene Film ◽  
Elastic Response ◽  
Hopkinson Pressure Bar ◽  
Compressive Properties ◽  
Foam Structure ◽  
The Impact

The purpose of this study is to elucidate the effect of foam structure on the impact compressive properties of foamed polyethylene film. Three types of foamed PE film were prepared, which have different foam structure: base type, spheral type and dense type. A quasi-static test was performed using a universal testing machine at the strain rate of 10-3~10-1s-1. Impact tests were carried out using a drop-weight testing machine at the strain rate of 101~102s-1 and using a split Hopkinson pressure bar method at the strain rate of approximately 103s-1. It was confirmed that the foamed PE film shows an increase of the flow stress with increasing of the strain rate, regardless of the specimen type. In the spheral type specimen, the elastic response is observed immediately after compression because the cell shape of this specimen has high bending resistance in comparison with the other two specimens. In addition, it is confirmed that the relative density and cell size affects the flow stress in the foamed PE film.

scholarly journals Impact Compressive Failure of a Unidirectional Carbon/Epoxy Composite: Effect of Loading Directions

2008 ◽  
Vol 13-14 ◽  
pp. 195-201 ◽  
Author(s):  
Takashi Yokoyama ◽  
Kenji Nakai
Keyword(s):  
Strain Rate ◽  
Cross Sections ◽  
Split Hopkinson Pressure Bar ◽  
Epoxy Composite ◽  
Compressive Strain ◽  
Testing Machine ◽  
Compressive Failure ◽  
Hopkinson Pressure Bar ◽  
Composite Effect ◽  
The Impact

The impact compressive failure behaviour of a unidirectional T700/2521 carbon/epoxy composite in three principal material directions is investigated in the conventional split Hopkinson pressure bar. Two different types of specimens with square cross sections are machined from the composite in the plane of the laminate. The uniaxial compressive stress-strain curves up to failure at quasi-static and intermediate strain rates are measured on an Instron testing machine. It is demonstrated that the ultimate compressive strength (or maximum stress) increases slightly, while the ultimate compressive strain (or failure strain) decreases marginally with strain rate in the range of 10-3 to 103/s in all three directions. Dominant failure mechanisms are found to significantly vary with strain rate and loading directions along three principal material axes.

Effect of Strain Rate on Mechanical Properties of Pure Iron

2013 ◽  
Vol 705 ◽  
pp. 21-25 ◽  
Author(s):  
Wei Ping Bao ◽  
Zhi Ping Xiong ◽  
Xue Ping Ren ◽  
Fu Ming Wang
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Work Hardening ◽  
Pure Iron ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Hopkinson Pressure Bar ◽  
Hardening Effect ◽  
Split Hopkinson ◽  
Pressure Bar

Effect of strain rate on mechanical properties of pure iron was studied by compression experiments using Gleebe-1500D thermal simulation testing machine and Split-Hopkinson Pressure Bar, indicating that pure iron only has strain rate hardening effect. Adiabatic temperature rise tends to increase with increasing the strain rate. Work hardening effect is also analyzed. It found that there are only two work hardening regions in static stage (10-3 to 1 s-1) while there are three work hardening regions in dynamic stage (650 to 8500 s-1). It is on account of onset of twining at high strain rates.

Study on Constitutive Relationship of Fe-36Ni Invar Alloy

2011 ◽  
Vol 291-294 ◽  
pp. 1131-1135
Author(s):  
Guo He Li ◽  
Yu Jun Cai ◽  
Hou Jun Qi
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Constitutive Relationship ◽  
Invar Alloy ◽  
Hopkinson Pressure Bar ◽  
Universal Testing ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Relationship Of

By electronic universal testing machine and Split Hopkinson Pressure Bar, the mechanical properties data of Fe-36Ni invar alloy are gained at a range of temperature from 20°C to 800°C and strain rate from 10-3 /s to 104/s. An improved Johnson-Cook model is presented to describe the mechanical behavior of Fe-36Ni invar alloy at high temperature and high strain rate, and verified by experimental results.

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