The Dynamic Mechanical Properties of CBF Composite Plate and its Sandwich Structure with Aluminum Foam Core

2010 ◽  
Vol 452-453 ◽  
pp. 281-284
Author(s):  
Zhong Liang Chang ◽  
Guang Ping Zou ◽  
Wei Ling Zhao ◽  
Yang Cao ◽  
Rui Rui Wang

The continuous basalt fiber (CBF) as inorganic fiber obtained from the basalt melt. It has high elastic modulus, low bulk density, low thermal conductivity, low moisture absorption rate and excellent alkali resistance, etc. In this paper, the split Hopkinson pressure bar (SHPB) technique is used for testing the CBF composite plate and its sandwich structure with aluminum foam core dynamic mechanical properties, and then to study the dynamic properties of CBF composite plate and its aluminum foam sandwich structure under different high strain rate. From the test results we can see that the CBF-foam aluminum sandwich structure has superior energy absorption properties, and also from the experiment results we can obtain that the sandwich structure dynamic stress-strain curves has a typically "three-phase" characteristics and strain rate effect.


2016 ◽  
Vol 1136 ◽  
pp. 543-548 ◽  
Author(s):  
Qing Feng Liu ◽  
Ning Chang Wang ◽  
Lan Yan ◽  
Feng Jiang ◽  
Hui Huang

The dynamic mechanical properties of oxygen free copper has been tested under the different strain rate (4700s-1~21000s-1) at the room temperature by split Hopkinson pressure bar (SHPB), the true stress-true strain curves has been obtained. Power-Law constitutive model and Johnson-Cook constitutive model have been built to fit the experimental result from SHPB test of oxygen free copper, meanwhile, the constitutive model can be applied to the simulation analysis of cutting process. The results show that the oxygen free copper is sensitive to the strain rate. In addition, the Johnson-Cook constitutive model predicts the plastic flow stress of the oxygen free copper more accurately than the Power-Law constitutive model at the high strain rate.



Author(s):  
Jun-Zhong Liu ◽  
Jin-Yu Xu ◽  
Xiao-Cong Lv ◽  
De-Hui Zhao ◽  
Bing-Lin Leng

Abstract In order to investigate rock dynamic mechanical properties of amphibolites, sericite-quartz schist and sandstone under the different strain rates varying from 30 s -1 to 150 s -1 , the specimens were subjected to axial impact at different projectile speeds by using the split Hopkinson pressure bar (SHPB) of 100 mm in diameter. The optimal experimental size of rock samples is verified by analyzing the stress equilibrium of cylindrical rock samples in different thicknesses. It has studied the mechanic properties of these three rocks which under impact loadings; and analysed the dynamic compressive strength, failure modes, energy dissipation variation with the strain-rate and the strain-rate hardening effect from the perspective of material microstructure. Experimental results show that the dynamic Young's modulus of rock samples increase with strain-rate slightly. The dynamic failure modes of different rock samples are always different. When at a lower strain-rate, the damage of sandstone takes a peeling off the external radial tensile failure mode, but that of amphibolites takes axial splitting mode; when at a higher strain-rate, sandstone takes granular crushing failure mode, and that of amphibolites and of sericite-quartz schist take massive crushing mode. Significant strain-rate effect can be represented by a linear relation between the specific energy absorption and the strain-rate , or between the dynamic strength increase factor η and .



2014 ◽  
Vol 1049-1050 ◽  
pp. 346-353
Author(s):  
Lei Fang ◽  
De Hua Deng ◽  
Jian Wei Peng ◽  
Yong Wang ◽  
Qing Tian

Dynamic mechanical properties of high elastic type cement and asphalt mortar (CA mortar) for high-speed railway was studied by split Hopkinson pressure bar (SHPB) in this paper. The experimental result show that the compressive strength of CA mortar increases gradually with the increasing of strain-rate. However, the increasing rate of compressive of CA mortar decreases with the further increasing strain-rate. The increasing rate of compressive strength is 57.65% for the strain-rate ranging from 25.16 s-1to 35.79 s-1 and 20.39% for the strain-rate from 94.64 up to 111.15 s-1, respectively. The larger the strain-rate is, the more serious the cracking is when CA mortar specimen damaged. The specific energy adsorption of CA mortar increases with the increasing strain-rate.



2011 ◽  
Vol 471-472 ◽  
pp. 385-390 ◽  
Author(s):  
Mohd Firdaus Omar ◽  
Md Akil Hazizan ◽  
Zainal Arifin Ahmad

Strain rate sensitivity and dynamic mechanical properties of polymeric materials are affected to a certain extent especially by the rate of loading. However, there is limited number of works reported on that particular issue. Therefore, the paper presents on static and dynamic mechanical properties of various polymeric materials across strain rate from 10-2 to 10-3 s-1. The specimen were tested using universal testing machine (UTM) for static loading and a conventional split Hopkinson pressure bar (SHPB) apparatus for dynamic loading. From the results, the compression modulus and compressive strength of all tested specimen increased significantly with increasing strain rates. In addition, positive increment in terms of strain rate sensitivity was recorded for all tested polymers over a wide range of strain rate investigated. Meanwhile, the thermal activation volume has decreased as increasing strain rate. Of the three polymers, polypropylene shows the highest strain rate sensitivity at static region. On the other hand, at dynamic region, polycarbonate shows the highest strain rate sensitivity than that of polypropylene and polyethylene.



2014 ◽  
Vol 692 ◽  
pp. 179-186
Author(s):  
Wei Ping Bao ◽  
Zhi Ping Xiong ◽  
Fu Ming Wang ◽  
Jian Shu ◽  
Xue Ping Ren

Dynamic mechanical properties and microstructures of pure iron and Fe-30Mn-3Si-4Al TWIP (TWinning Induced Plasticity) steel were conducted by SHPB (Split-Hopkinson Pressure Bar), OM (Optical Microscopy) and TEM (Transmission Electron Microscope), at the strain rate ranging from 102 to 105 s-1 and at room temperature. The effect of high strain rate on the mechanical responses of pure iron and Fe-30Mn-3Si-4Al TWIP steel belonging to BCC (Body Centered Cubic) and FCC (Face Centered Cubic) structures respectively was evaluated. The comparison of deformation mechanism was analyzed between them and it concluded that dislocation gliding is a major deformation mechanism in pure iron with BCC structure and deformation twinning plays a significant role in Fe-30Mn-3Si-4Al TWIP steel with FCC structure.



2016 ◽  
Vol 649 ◽  
pp. 35-38 ◽  
Author(s):  
S.G. Ma ◽  
Z.M. Jiao ◽  
J.W. Qiao ◽  
H.J. Yang ◽  
Y. Zhang ◽  
...  


2018 ◽  
Vol 910 ◽  
pp. 123-129 ◽  
Author(s):  
X.N. Mu ◽  
H.N. Cai ◽  
Hong Mei Zhang ◽  
Q.B. Fan ◽  
Y. Wu

In this study, the titanium matrix composites (TiMCs) were fabricated by adding graphene nanoplatelets (GNPs). The dynamic compression test was carried out to study the effect of strain-rate and the GNPs content on dynamic mechanical properties of GNPs/Ti. Results show that the GNPs content (0wt%~0.8wt%) correspond to specific microstructure which affect the dynamic mechanical properties of the composites. Under high strain-rate (3500s-1), the 0.4wt%GNPs/Ti has the highest dynamic stress (~1860MPa) and strain (~30%). The adiabatic shearing band (ASB) microstructure of GNPs/Ti with various GNPs content has been observed under 3500s-1 strain-rate and the ASB microstructure evolution of 0.4wt%GNPs/Ti under different strain rate was investigated in particular.



Entropy ◽  
2019 ◽  
Vol 21 (12) ◽  
pp. 1154
Author(s):  
Bingfeng Wang ◽  
Chu Wang ◽  
Bin Liu ◽  
Xiaoyong Zhang

The dynamic mechanical properties and microstructure of the (Al0.5CoCrFeNi)0.95Mo0.025C0.025 high entropy alloy (HEA) prepared by powder extrusion were investigated by a split Hopkinson pressure bar and electron probe microanalyzer and scanning electron microscope. The (Al0.5CoCrFeNi)0.95Mo0.025C0.025 HEA has a uniform face-centered cubic plus body-centered cubic solid solution structure and a fine grain-sized microstructure with a size of about 2 microns. The HEA possesses an excellent strain hardening rate and high strain rate sensitivity at a high strain rate. The Johnson–Cook plastic model was used to describe the dynamic flow behavior. Hat-shaped specimens with different nominal strain levels were used to investigate forced shear localization. After dynamic deformation, a thin and short shear band was generated in the designed shear zone and then the specimen quickly fractured along the shear band.



Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2105 ◽  
Author(s):  
Alon Ratner ◽  
Richard Beaumont ◽  
Iain Masters

Strain rate sensitivity has been widely recognized as a significant feature of the dynamic mechanical properties of lithium-ion cells, which are important for their accurate representation in automotive crash simulations. This research sought to improve the precision with which dynamic mechanical properties can be determined from drop tower impact testing through the use of a diaphragm to minimize transient shock loads and to constrain off-axis motion of the indenter, specialized impact absorbers to reduce noise, and observation of displacement with a high speed camera. Inert pouch cells showed strain rate sensitivity in an increased stiffness during impact tests that was consistent with the poromechanical interaction of the porous structure of the jellyroll with the liquid electrolyte. The impact behaviour of the inert pouch cells was similar to that of an Expanded Polypropylene foam (EPP), with the exception that the inert pouch cells did not show hysteretic recovery under the weight of the indenter. This suggests that the dynamic mechanical behaviour of the inert pouch cells is analogous to a highly damped foam.



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