scholarly journals Microstructure Evolution Mechanism of Wf/Cu82Al10Fe4Ni4 Composites under Dynamic Compression at Different Temperatures and Strain Rates

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5563
Author(s):  
Zhe Wu ◽  
Yang Zhang ◽  
Haifeng Jiang ◽  
Shuai Zhao ◽  
Qingnan Wang
Keyword(s):  
Copper Alloy ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Stacking Faults ◽  
High Density ◽  
Second Phase ◽  
Strain Rates ◽  
Alloy Matrix ◽  
Pressure Infiltration ◽  
Different Temperatures

Wf/Cu82Al10Fe4Ni4 composites were fabricated by the pressure infiltration method. The composites were compressed by means of a split Hopkinson pressure bar (SHPB) with strain rates of 800 and 1600 s−1 at different temperatures. The microstructure of the composites after dynamic compressing was analyzed by transmission electron microscopy (TEM). Observation revealed that there were high-density dislocations, stacking faults, twins, and recrystallization existing in the copper alloy matrix of the composites. High-density dislocations, stacking faults, and twins were generated due to the significant plastic deformation of the copper alloy matrix under dynamic load impact. We also found that the precipitated phase of the matrix played a role in the second phase strengthening; recrystallized microstructures of copper alloy were generated due to dynamic recrystallization of the copper alloy matrix under dynamic compression at high temperatures.

Microstructural and Dynamic Mechanical Characterization of Biodegradable Magnesium-Calcium Alloy for Orthopedic Implants

2014 ◽  
Author(s):  
V. S. Brooks ◽  
Y. B. Guo
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Orthopedic Implants ◽  
Strain Rates ◽  
High Strain Rates ◽  
Static Compression ◽  
Metallic Biomaterial

Magnesium-Calcium (Mg-Ca) alloy is an emerging metallic biomaterial for manufacturing biodegradable orthopedic implants. However, very few studies have been conducted on mechanical properties of the bi-phase Mg-Ca alloy, especially at the high strain rates often encountered in manufacturing processes. The mechanical properties are critical to design and manufacturing of Mg-Ca implants. The objective of this study is to study the microstructural and mechanical properties of Mg-Ca0.8 (wt %) alloy. Both elastic and plastic behaviors of the Mg-Ca0.8 alloy were characterized at different strains and strain rates in quasi-static tension and compression testing as well as dynamic split-Hopkinson pressure bar (SHPB) testing. It has been shown that Young’s modulus of Mg-Ca0.8 alloy in quasi-static compression is much higher than those at high strain rates. Yield strength and ultimate strength of the material are very sensitive to strain rates and increase with strain rate in compression. Strain softening also occurs at large strains in dynamic compression. Furthermore, quasi-static mechanical behavior of the material in tension is very different from that in compression. The stress-strain data was repeatable with reasonable accuracy in both deformation modes. In addition, a set of material constants for the internal state variable plasticity model has been obtained to model the dynamical mechanical behavior of the novel metallic biomaterial.

scholarly journals Dynamic Constitutive Model of Ultra-High Molecular Weight Polyethylene (UHMWPE): Considering the Temperature and Strain Rate Effects

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1561 ◽  
Author(s):  
Kebin Zhang ◽  
Wenbin Li ◽  
Yu Zheng ◽  
Wenjin Yao ◽  
Changfang Zhao
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Plastic Material ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Ballistic Performance ◽  
Stress Strain ◽  
Different Temperatures

The temperature and strain rate significantly affect the ballistic performance of UHMWPE, but the deformation of UHMWPE under thermo-mechanical coupling has been rarely studied. To investigate the influences of the temperature and the strain rate on the mechanical properties of UHMWPE, a Split Hopkinson Pressure Bar (SHPB) apparatus was used to conduct uniaxial compression experiments on UHMWPE. The stress–strain curves of UHMWPE were obtained at temperatures of 20–100 °C and strain rates of 1300–4300 s−1. Based on the experimental results, the UHMWPE belongs to viscoelastic–plastic material, and a hardening effect occurs once UHMWPE enters the plastic zone. By comparing the stress–strain curves at different temperatures and strain rates, it was found that UHMWPE exhibits strain rate strengthening and temperature softening effects. By modifying the Sherwood–Frost model, a constitutive model was established to describe the dynamic mechanical properties of UHMWPE at different temperatures. The results calculated using the constitutive model were in good agreement with the experimental data. This study provides a reference for the design of UHMWPE as a ballistic-resistant material.

Strain-Rate Dependence of Compressive Yield Strength of Titanium Grade 4 with Coarse-Grained and Ultrafine-Grained Structures: Experimental Results and Theoretical Calculation

2018 ◽  
Vol 1145 ◽  
pp. 100-105
Author(s):  
Ivan V. Smirnov ◽  
Alexander Y. Konstantinov
Keyword(s):  
Yield Strength ◽  
Strain Rate ◽  
Yield Stress ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Pure Titanium ◽  
Coarse Grained ◽  
Strain Rates ◽  
Ultrafine Grained ◽  
Titanium Grade

The nanocrystalline (NC) and ultrafine-grained (UFG) structures of metallic materials can lead to their extraordinary high strength. However, most of the papers on this topic consider deformation parameters of NC and UFG materials only for the case of quasi-static tensile tests. Characteristics of dynamic strength and fracture of such materials remain unexplored. This paper presents a study of the mechanical behavior of pure titanium Grade 4 with a coarse-grained (CG) and UFG structure under uniaxial compression with different strain rates. The UFG structure was provided using the method of equal-channel angular pressing. The dynamic compression was carried out on a setup with the Split-Hopkinson pressure bar. It is found that in the observed range of strain rates 10–3-3×103 s–1, the yield stress of the CG titanium increases by 20%, and does not exceed the yield stress of the UFG titanium. However, the yield stress of the UFG titanium remains close to a quasi-static value. It is shown that these strain-rate dependencies of the yield strength can be predicted by the incubation time approach. The calculated curves show that at strain rates above 104 s–1 the yield stress of the CG titanium becomes higher than the yield strength of the UFG titanium.

Dynamic Constitutive Relation of EMC

2010 ◽  
Vol 129-131 ◽  
pp. 988-992
Author(s):  
Bo Wang ◽  
Tong Chen ◽  
Xue Feng Shu
Keyword(s):  
Yield Strength ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Static Tests ◽  
Good Accordance ◽  
Different Temperatures ◽  
Split Hopkinson ◽  
Pressure Bar

In this paper, dynamic properties of EMC were studied at different temperatures and different strain rates. Firstly EMC was investigated by quasi-static tests. Secondly a series of dynamic compressive experiments of EMC were conducted using the Split Hopkinson Pressure Bar (SHPB) at sectional height of strain rates. Thirdly EMC constants in ZWT model were determined from experiments. Corresponding measurements were conducted at temperatures ranging from 20°C to 160°C. The results indicate that the yield strength and flow stress of EMC increase remarkably with the increase of strain rate and it is shows that the assembled curve is fit good accordance with actual the experimental curve. However, the yield strength of EMC is a little change with the increase of temperature which is ranging from 20°C to 160°C.

scholarly journals Dynamic deformations tests of Ni3Al based intermetallic alloy by using the split Hopkinson pressure bar technique

2019 ◽  
Vol 55 (1) ◽  
pp. 129-134
Author(s):  
P. Jozwik ◽  
M. Kopec ◽  
W. Polkowski ◽  
Z. Bojar
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Intermetallic Alloy ◽  
Strong Impact ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Evaluation Point ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Deformation Tests

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.

scholarly journals Effect of CNTs Additives on the Energy Balance of Carbon/Epoxy Nanocomposites during Dynamic Compression Test

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 194 ◽  
Author(s):  
Manel Chihi ◽  
Mostapha Tarfaoui ◽  
Chokri Bouraoui ◽  
Ahmed El Moumen
Keyword(s):  
Carbon Fiber ◽  
Energy Absorption ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Dynamic Compression ◽  
Fiber Reinforced Polymers ◽  
Strain Rates ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Carbon Fiber Reinforced

Previous research has shown that nanocomposites show not only enhancements in mechanical properties (stiffness, fracture toughness) but also possess remarkable energy absorption characteristics. However, the potential of carbon nanotubes (CNTs) as nanofiller in reinforced epoxy composites like glass fiber-reinforced polymers (GFRP) or carbon fiber-reinforced polymers (CFRP) under dynamic testing is still underdeveloped. The goal of this study is to investigate the effect of integrating nanofillers such as CNTs into the epoxy matrix of carbon fiber reinforced polymer composites (CFRP) on their dynamic energy absorption potential under impact. An out-of-plane compressive test at high strain rates was performed using a Split Hopkinson Pressure Bar (SHPB), and the results were analyzed to study the effect of changing the concentration of CNTs on the energy absorption properties of the nanocomposites. A strong correlation between strain rates and CNT mass fractions was found out, showing that an increase in percentage of CNTs could enhance the dynamic properties and energy absorption capabilities of fiber-reinforced composites.

High Strain Rate Behavior of Carbon Nanotubes Reinforced Aluminum Foams

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Abdelhakim Aldoshan ◽  
D. P. Mondal ◽  
Sanjeev Khanna
Keyword(s):  
Carbon Nanotubes ◽  
Strain Rate ◽  
Aluminum Foam ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Strain Rates ◽  
Aluminum Foams ◽  
Static Compression ◽  
Closed Cell

The mechanical behavior of closed-cell aluminum foam composites under different compressive loadings has been investigated. Closed-cell aluminum foam composites made using the liquid metallurgy route were reinforced with multiwalled carbon nanotubes (CNTs) with different concentrations, namely, 1%, 2%, and 3% by weight. The reinforced foams were experimentally tested under dynamic compression using the split Hopkinson pressure bar (SHPB) system over a range of strain rates (up to 2200 s−1). For comparison, aluminum foams were also tested under quasi-static compression. It was observed that closed-cell aluminum foam composites are strain rate sensitive. The mechanical properties of CNT reinforced Al-foams, namely, yield stress, plateau stress, and energy absorption capacity are significantly higher than that of monolithic Al-foam under both low and high strain rates.

Dynamic Response of Symmetric and Asymmetric E-Glass / Epoxy Laminates at High Strain Rates

2010 ◽  
Vol 446 ◽  
pp. 73-82 ◽  
Author(s):  
Mostapha Tarfaoui ◽  
S. Choukri ◽  
A. Neme
Keyword(s):  
Maximum Stress ◽  
Failure Modes ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
High Speed Photography ◽  
Strain Rates ◽  
High Strain Rates ◽  
Stress Strain ◽  
Out Of Plane

The mechanical properties of E-glass/epoxy composite at high strain rates are important in evaluating this kind of composite under dynamic and impulsive loading. The in-plane and out-of-plane compressive properties at strain rates from 300 to 2500 s-1 were tested with split Hopkinson pressure bar. Samples were tested in the thickness as well as in-plane direction for seven fibre orientations: 0°, 20°, 30°, 45°, 60°, 70° and 90°. The kinetics of damage and the failure modes were identified using a high-speed photography, infrared camera, optical techniques and a scanning electron microscope. Results of the study were analyzed in terms of maximum stress, Strain at maximum stress, failure modes, damage history and fibres orientation effects. From the experimental data, the stress-strain curves, compressive stiffness, and compressive strain of the composite are rate-sensitive in in-plane and out-of-plane compressive directions. The failure and damage mechanisms are implicitly related to the rise in temperature during static and dynamic compression.

scholarly journals The Out-of-Plane Compression Response of Woven Thermoplastic Composites: Effects of Strain Rates and Temperature

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 264
Author(s):  
Shiyu Wang ◽  
Lihua Wen ◽  
Jinyou Xiao ◽  
Ming Lei ◽  
Xiao Hou ◽  
...  
Keyword(s):  
Strain Rate ◽  
Elevated Temperatures ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Dynamic Compression ◽  
Polyphenylene Sulfide ◽  
Thermoplastic Composites ◽  
Strain Rates ◽  
Wide Range ◽  
Out Of Plane

The dynamic mechanical response of high-performance thermoplastic composites over a wide range of strain rates is a challenging research topic for extreme environmental survivability in the field of aerospace engineering. This paper investigates the evolution of the dynamic properties of woven thermoplastic composites with strain rate and damage process at elevated temperatures. Out-of-plane dynamic-compression tests of glass-fiber (GF)- and carbon-fiber (CF)-reinforced polyphenylene sulfide (PPS) composites were performed using a split Hopkinson pressure bar (SHPB). Results showed that thermoplastic composites possess strain-rate strengthening effects and high-temperature weakening dependence. GF/PPS and CF/PPS composites had the same strain-rate sensitivity (SRS) below the threshold strain rate. The softening of the matrix at elevated temperatures decreased the modulus but had little effect on strength. Some empirical formulations, including strain-rate and temperature effects, are proposed for more accurately predicting the out-of-plane dynamic-compression behavior of thermoplastic composites. Lastly, the final failure of the specimens was examined by scanning electron microscopy (SEM) to explore potential failure mechanisms, such as fiber-bundle shear fracture at high strain rates and stretch break at elevated temperatures.

Strain rates effect of dynamic compression properties of E-glass / jute composite

2020 ◽  
Vol 14 (3) ◽  
pp. 7162-7169
Author(s):  
Muhamad Shahirul Mat Jusoh ◽  
Mohd Yazid Yahya ◽  
Haris Ahmad Israr Ahmad
Keyword(s):  
Mechanical Properties ◽  
Hybrid Composite ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Testing ◽  
Dynamic Compression ◽  
Compressive Strain ◽  
Dynamic Mechanical Properties ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Dynamic Mechanical

Presently, the application of natural fibres widely gains attention from academia and industries as an alternative material in the composite system. The introduction of the hybrid composite using natural and synthetic fibres is extensively investigated on the static mechanical properties. However, the investigation on the high strain-rates effect is less reported due to the difficulty of the experimental set-up as well as the limitation of dynamic testing apparatus. The split Hopkinson pressure bar (SHPB) was utilised in this present study to characterise the dynamic mechanical properties of the hybrid composite between E-glass with jute fibres at three different strain rates of 755, 1363, and 2214 s−1. Results showed that the dynamic compression stress and strain of the tested samples significantly influenced by the value of strain rates applied. The E-glass/jute sample exhibited the strain-rate dependent behaviour, whereby the higher dynamic mechanical properties were recorded when the higher strain rates were imposed. The difference between maximum dynamic stress was 12.1 and 23.9% when the strain rates were increased from 755 to 1363 s−1 and 1363 to 2214 s−1, respectively. In terms of compressive strain, the maximum compressive strain was recorded when the lower strain rates were imposed during testing.

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