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

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

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Liang Bian ◽  
Jian Ma ◽  
Jie Zhang ◽  
Ping Li

The dynamic behavior of steel fibre reinforced self-compacting concrete (SFRSCC) was investigated by using a split Hopkinson pressure bar (SHPB). SFRSCC specimens with two strength classes of about 40 MPa and 60 MPa were prepared. Different steel fibre volume fractions were used varying from 0.5% to 2.0%. The tested strain rate ranged from about 50 to 240 s−1. Significant rate dependence was observed, and dynamic increase factor (DIF) was used to quantify the rate sensitivity. The results showed that both the matrix strength and fibre content had effect on the strain rate sensitivity of SFRSCC. A DIF formula was proposed for describing the dynamic strength of SFRSCC at high strain rates, and a dynamic damage constitutive model was derived to describe the stress-strain relationship of SFRSCC. The parameters in the model were determined by fitting the experimental data. Good consistency between theoretical curves and experimental data was obtained.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9444-9461
Author(s):  
Damian Stoddard ◽  
Suman Babu Ukyam ◽  
Brent Tisserat ◽  
Ivy Turner ◽  
Rowan Baird ◽  
...  

Novel bio-based composite wood panels (CWPs) that consisted of distiller’s dried grains and solubles (DDGS) flour adhesive bound to a wood filler/reinforcement were subjected to high strain-rate compression loading, and their behavior was investigated. Specimens of DDGS-Paulownia wood (PW) or DDGS-pinewood (Pine) composites made using DDGS with fractions of 10%, 15%, 25%, and 50% were tested at high strain-rates using a modified compression Split Hopkinson Pressure Bar (SHPB). Both DDGS-PW and DDGS-Pine composites displayed strain-rate sensitivity, and DDGS-PW had a 25% fraction, which showed the highest ultimate compressive strength of 655 MPa at approximately 1600/s. The 90%-PW had the highest specific energy of 19.24 kJ/kg at approximately 1600/s when loaded via dynamic compression. The CWPs constructed of DDGS-PW had higher strength and energy absorption than DDGS-Pine with the exception of the 50% DDGS composites.


2017 ◽  
Vol 5 (2) ◽  
pp. 20-30
Author(s):  
Zaman Khalil Ibrahim

In this research aluminum matrix composites (AMCs) was reinforced by titanium carbide (TiC) particles and was produced. Powder metallurgy technique (PM) has been used to fabricate AMCs reinforced with various amounts (0%, 4%, 8%, 12%, 16% and 20% volume fraction) of TiC particles to study the effect of different volume fractions on mechanical properties of the Al-TiC composites. Measurements of compression strength and hardness showed that mechanical properties of composites increased with an increase in volume fraction of TiC Particles. Al-20 % vol. TiC composites exhibited the best properties with hardness value (97HRB) and compression strength value (275Mpa).


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.


2007 ◽  
Vol 546-549 ◽  
pp. 639-642
Author(s):  
De Zhi Zhu ◽  
Gao Hui Wu ◽  
Long Tao Jiang ◽  
Guo Qin Chen

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.


1993 ◽  
Vol 323 ◽  
Author(s):  
Shy-Wen Lai ◽  
D. D. L. Chung

AbstractAluminum-matrix composites containing AIN or SiC particles were fabricated by vacuum infiltration of liquid aluminum into a porous particulate preform under an argon pressure of up to 41 MPa. Al/AIN was superior to Al/SiC in thermal conductivity. At 59 vol.% AIN, Al/AlN had a thermal conductivity of 157 W/m. °C and a thermal expansion coefficient of 9.8 × 10−-6°C−1 (35–100 °C). Al/AlN had similar tensile strength and higher ductility compared to Al/SiC of a similar reinforcement volume fraction at room temperature, but exhibited higher tensile strength and higher ductility at 300–400°C. The ductility of Al/AlN increased with increasing temperature from 22 to 400°C, while that of Al/SiC did not change with temperature. The superior high temperature resistance of Al/AlN is attributed to the lack of a reaction between Al and AIN, in contrast to the reaction between Al and SiC in AI/SiC.


2018 ◽  
Vol 183 ◽  
pp. 02012
Author(s):  
Miloslav Popovič ◽  
Jaroslav Buchar ◽  
Martina Drdlová

The results of dynamic compression and tensile-splitting tests of concrete reinforced by randomly distributed short non – metallic fibres are presented. A Split Hopkinson Pressure Bar combined with a high-speed photographic system, was used to conduct dynamic Brazilian tests. Quasi static test show that the reinforcement of concrete by the non-metallic fibres leads to the improvement of mechanical properties at quasi static loading. This phenomenon was not observed at the high strain rate loading .Some explanation of this result is briefly outlined.


2014 ◽  
Vol 1017 ◽  
pp. 98-103
Author(s):  
Fei Hu Zhang ◽  
Kai Wang ◽  
Peng Qiang Fu ◽  
Meng Nan Wu

With silicon particles reinforced aluminum matrix composites with high volume fraction becoming a new hotspot on research and application in the aerospace materials and electronic packaging materials, the machinability of this material needs to be explored. This paper reports research results obtained from the surface grinding experiment of silicon particles reinforced aluminum matrix composites using black silicon carbide wheel, green silicon carbide wheel, white fused alumina wheel and chromium alumina wheel. The issues discussed are grinding force, surface roughness, the comparison of different grinding wheels, the micro-morphology of the work piece. The results showed that the grinding force was related with the grinding depth and the grinding wheel material, the grinding force was increasing as the grinding depth growing. The surface roughness was between 0.29μm and 0.48μm using the silicon carbide wheel. The surface of the work piece had concaves caused by silicon particles shedding and grooves caused by the grains observed by the SEM and CLSM.


2012 ◽  
Vol 535-537 ◽  
pp. 110-116
Author(s):  
Xian Feng Li ◽  
Bin Liu ◽  
Wen Mao Huang ◽  
Hao Wei Wang

Particles size grading method was employed to fabricate aluminum matrix composites reinforced with 75% volume fraction B4C particles by squeeze casting. Dynamic behaviors of the composite was investigated and compared with 55 vol. % composite which were reinforced with particles of uniform size. The results showed that the flow stress increased but the fracture strain decreased with increasing reinforcement volume fraction. Furthermore, the dynamic behaviors of 55 vol. % composite were significantly affected by adiabatic heating softening which was demonstrated by the local melted matrix on the fracture surface and an increase-decrease tendency on flow stress and failure strain was obtained with increasing impact velocity. However, due to load redistribution caused by particles size grading, no melted region was found on the fracture surface and no increase-decrease tendency on flow stress and failure strain was observed for 75 vol. % composites under the same impact loading.


Sign in / Sign up

Export Citation Format

Share Document