Study on the Constitutive Model of SiCp/Al Composites

2016 ◽  
Vol 693 ◽  
pp. 621-628 ◽  
Author(s):  
Xi Guo Xue ◽  
Li Jing Xie ◽  
Tao Wang

By conducting the quasi-static compression and split Hopkinson pressure bar testing,the flow strain - stress curves under strain rate range of 0.0001-1000/s and temperature range of normal-400°C of different volume fraction SiC particles reinforced metal matrix composite SiCp/6063Al were obtained. The commonly used Johnson-Cook constitutive model in metal materials was applied in this research. And on the basis of it, the influence of volume fraction to flow stress was utilized to establish the equivalent and homogeneous constitutive model.

2020 ◽  
Vol 1012 ◽  
pp. 89-93
Author(s):  
Anderson Oliveira da Silva ◽  
Ricardo Pondé Weber ◽  
Sergio Neves Monteiro

This work evaluates the mechanical and dynamic behavior of recycled polycarbonate (rPC) from industrial waste. This study aims to verify whether the recycled process adopted for polycarbonate promotes both mechanical and dynamic properties values under compressive stress, similar to those found for virgin polycarbonate. The mechanical recycling of the rPC was carried out using the thermoforming technique in a thermal press. Two tests were carried out to evaluate the dynamic response of rPC. The quasi-static compression test was performed on a universal machine. The dynamic in a split Hopkinson pressure bar was performed with three different strain rates. The results showed that the mechanical and primary recycling adopted in this work promoted values of yield stress in compression (77 MPa) and dynamic (up to 118 MPa), close to or superior to those reported so far in the literature.


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.


2017 ◽  
Vol 27 (5) ◽  
pp. 686-706 ◽  
Author(s):  
Zhiwu Zhu ◽  
Zhijie Liu ◽  
Qijun Xie ◽  
Yesen Lu ◽  
Dingyun Li

To reveal the influences of soil particle size on the dynamic impact mechanical properties of frozen soil, four groups of frozen soil specimens composed of different particle sizes are tested using a split-Hopkinson pressure bar. Based on the Druger–Prager failure criterion and coupled damage-plasticity, a dynamic micro-constitutive model is established for describing the dynamic mechanical behavior of the frozen soil. Macroscopically, frozen soil is assumed to be homogeneous and continuous, although a large number of micro-cracks and micro-voids are distributed randomly throughout the volume. When a frozen soil specimen is subjected to a substantial shock, the propagation of micro-cracks and the collapse of micro-voids can induce damage. The evolution equations of the two damage mechanisms are proposed. Finally, through a comparison, it was shown that simulation results agreed well with the experimental results, thus validating the suitability of the developed model.


Author(s):  
Yihang Fan ◽  
Bing Wang ◽  
Zhaopeng Hao

In this study, the effects of strain rate and temperature on the flow stress of Inconel718 were analyzed by Split Hopkinson Pressure Bar (SHPB) experiment and quasi-static compression experiment. The classical JC constitutive model was established by combining the quasi-static compression experiment with the SHPB experiment. According to the effects of different grain sizes and [Formula: see text] phase on dislocation pile-up, the dislocation pile-up theory was introduced to modify the JC constitutive model. The modified constitutive model was compiled in FORTRAN language, and VUMAT user material subroutine was called and secondary development was carried out to establish the polycrystalline simulation model with different grain sizes. The uniaxial tensile and compression simulation process of polycrystal with different grain sizes was performed. Through comparing the simulation results with the experimental data. The correlation coefficient R, between the simulation and experimental values, is 0.97,981, and the average relative error is only 3.72%. The accuracy of the modified constitutive model was verified.


2011 ◽  
Vol 71-78 ◽  
pp. 809-814 ◽  
Author(s):  
Er Lei Bai ◽  
Jin Yu Xu ◽  
Zhi Gang Gao

The EPS concrete with 10%,20%,30%,40%,50% EPS volume fraction were prepared. Taking critical strain as the index, the deformation property of EPS concrete with different EPS volume fraction under impact loading were studied using a 100-mm-diameter split Hopkinson pressure bar(SHPB) apparatus. The results show that the deformation property of the EPS concrete increases with the average strain rate for the strain rate effect, which takes on obvious strain rate dependency. For the EPS microscopic structure effect, the deformation property of the EPS concrete increases with the EPS volume fraction in 0~40%. Its deformation property reduces somewhat when the EPS volume fraction reaches 50%. To improve the deformation property, the optimum volume fraction of EPS is 40%.


2011 ◽  
Vol 105-107 ◽  
pp. 1717-1722
Author(s):  
De Hui Zhao ◽  
Jin Yu Xu ◽  
Er Lei Bai

To study on the toughing effect of EPS in the plain concrete, the EPS concrete with 10%,20%,30%,40%,50% EPS volume fraction were prepared. Taking specific energy absorption as the index, the toughing effect of EPS concrete with different EPS volume fraction under impact loading were studied using a 100-mm-diameter split Hopkinson pressure bar(SHPB) apparatus, and the toughing effect mechanism of the concrete was discussed. The results show that the toughing effect of the EPS concrete increases with the average strain rate for the strain rate effect, which takes on obvious strain rate dependency. For the EPS microscopic structure effect, the toughing effect of the EPS concrete increases with the EPS volume fraction in 10~30%. Its toughing effect reduces somewhat when the EPS volume fraction reaches 40~50%. To improve the deformation property, the optimum volume fraction of EPS is 20%.


2013 ◽  
Vol 20 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Wojciech Moćko

Abstract The paper presents the results of the analysis of the striker shape impact on the shape of the mechanical elastic wave generated in the Hopkinson bar. The influence of the tensometer amplifier bandwidth on the stress-strain characteristics obtained in this method was analyzed too. For the purposes of analyzing under the computing environment ABAQUS / Explicit the test bench model was created, and then the analysis of the process of dynamic deformation of the specimen with specific mechanical parameters was carried out. Based on those tests, it was found that the geometry of the end of the striker has an effect on the form of the loading wave and the spectral width of the signal of that wave. Reduction of the striker end diameter reduces unwanted oscillations, however, adversely affects the time of strain rate stabilization. It was determined for the assumed test bench configuration that a tensometric measurement system with a bandwidth equal to 50 kHz is sufficient


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