Measurement on Strain Rate Sensitivity and Dynamic Mechanical Properties of Various Polymeric Materials

2011 ◽  
Vol 471-472 ◽  
pp. 385-390 ◽  
Author(s):  
Mohd Firdaus Omar ◽  
Md Akil Hazizan ◽  
Zainal Arifin Ahmad
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Rate Sensitivity ◽  
Polymeric Materials ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical ◽  
Wide Range

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.

scholarly journals Dynamic Mechanical Compression Impulse of Lithium-Ion Pouch Cells

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2105 ◽  
Author(s):  
Alon Ratner ◽  
Richard Beaumont ◽  
Iain Masters
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Lithium Ion ◽  
Rate Sensitivity ◽  
Dynamic Mechanical Properties ◽  
Impact Testing ◽  
Significant Feature ◽  
Dynamic Mechanical ◽  
The Impact

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.

Effect of Particle Sizes on Rate Sensitivity and Dynamic Mechanical Properties of Polypropylene/Silica (PP/Sio2) Nanocomposites

2011 ◽  
Vol 364 ◽  
pp. 181-185 ◽  
Author(s):  
Firdaus Omar Mohd ◽  
Md Akil Hazizan ◽  
Zainal Arifin Ahmad
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Strain Rate ◽  
Testing Machine ◽  
Rate Sensitivity ◽  
Dynamic Mechanical Properties ◽  
Particle Sizes ◽  
Rate Condition ◽  
Dynamic Mechanical ◽  
Silica Nanocomposites

Filler-related characteristic such as particle size, shape and geometry are essential factors that need to be considered during the evaluation of the material’s performance especially in the area of particle filled composites. However, there is limited number of works are reported on this particular issue under high strain rate condition. Based on this concern, the paper presents an experimental results on the effect of particle sizes towards rate sensitivity and dynamic compressive properties of polypropylene/silica nanocomposites across strain rate from 10-2to 10-3s-1. The composite specimens were tested using universal testing machine for static loading and a compression split Hopkinson pressure bar apparatus for dynamic loading. Results show that, the stiffness and strength properties of polypropylene/silica nanocomposites were affected by the size of silica particles. However, the magnitudes of changed are somehow different between micro and nanosizes. On the other hand, particle size also plays a major contribution towards sensitivity of the polypropylene/silica nanocomposites where the smaller the reinforcement sizes, the less sensitive would be the composites. Overall, it is convenience to say that the particle size gives significant contribution towards rate sensitivity and dynamic mechanical properties of polypropylene/silica nanocomposites.

scholarly journals Effect of the Strain Rate and Fiber Direction on the Dynamic Mechanical Properties of Beech Wood

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 881 ◽  
Author(s):  
Shumeng Pang ◽  
Yingjing Liang ◽  
Weijun Tao ◽  
Yijie Liu ◽  
Shi Huan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Beech Wood ◽  
Rate Sensitivity ◽  
Dynamic Mechanical Properties ◽  
Fiber Direction ◽  
Compression Tests ◽  
Static Compression ◽  
Dynamic Mechanical

As a macroscopically orthotropic material, beech wood has different mechanical properties along the fiber direction and the direction perpendicular to the fiber direction, presenting a complicated strain rate sensitivity under impact or blast loadings. To understand the effect of the strain rate on the mechanical properties of beech wood, dynamic compression tests were conducted for the strain rate range of 800 s−1–2000 s−1, and quasi-static compression tests for obtaining the static mechanical properties of beech wood were also performed for comparison. The fiber direction effect on the mechanical properties was also analyzed, considering two loading directions: one perpendicular to the beech fiber direction and the other parallel to the beech fiber direction. The results show that beech wood for both loading directions has a significant strain rate sensitivity, and the mechanical properties of beech wood along the fiber direction are superior to those along the direction perpendicular to the fiber direction. An analysis of the macrostructures and microstructures of beech specimens is also presented to illustrate the failure mechanisms. The beech wood, as a natural protective material, has special dynamic mechanical properties in the aspect of transverse isotropy. This research provides a theoretical basis for application in protective structures.

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
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Composite Plate ◽  
Sandwich Structure ◽  
Aluminum Foam ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Mechanical Properties ◽  
Alkali Resistance ◽  
Foam Core ◽  
Dynamic Mechanical

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.

Strain-Rate Sensitivity of Concrete: Influence of Temperature

2011 ◽  
Vol 243-249 ◽  
pp. 453-456
Author(s):  
Dong Ming Yan ◽  
Wei Xu
Keyword(s):  
Low Temperature ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Dynamic Properties ◽  
Testing Machine ◽  
Concrete Structures ◽  
Free Water ◽  
Rate Sensitivity ◽  
Influence Of Temperature ◽  
Wide Range

Knowledge about the dynamic properties of concrete is vital to the design and safety evaluation of large-scale concrete structures subjected to seismic excitation. There are many factors affecting the dynamic properties of concrete such as moisture content and temperature. Though a lot of concrete structures have been designed to withstand low temperature, research on the strain-rate sensitivity of concrete under low temperature condition is still very limited so far. In this study, both tensile and compressive experiments were carried out to investigate the influence of temperature on the rate-dependent characteristics of concrete. Tensile experiments of dumbbell-shaped specimens were carried out on a MTS810 testing machine and compressive tests on cubic specimens were performed using a servo-hydraulic testing machine. Specimens at two types of temperature, room temperature 20oC and low temperature -30oC, were characterized. The strain rate varied over a wide range. It was concluded from the test data that the strengths of specimens at both types of temperature tended to increase as strain rate increased. Temperature had slight influence on the rate-sensitive behavior of concrete when concrete specimens were dry; however, test on saturated specimens indicated that the role of temperature on the mechanical behavior of concrete subject to dynamic loading was very significant. This phenomenon may be attributed to the state of free water in concrete.

The Dynamic Mechanical Properties of Oxygen Free Copper under the Impact Load

2016 ◽  
Vol 1136 ◽  
pp. 543-548 ◽  
Author(s):  
Qing Feng Liu ◽  
Ning Chang Wang ◽  
Lan Yan ◽  
Feng Jiang ◽  
Hui Huang
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Strain Rate ◽  
Power Law ◽  
Split Hopkinson Pressure Bar ◽  
True Strain ◽  
Dynamic Mechanical Properties ◽  
Experimental Result ◽  
Dynamic Mechanical ◽  
The Impact

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.

Experimental Study on Dynamic Mechanical Properties of Amphibolites, Sericite-quartz Schist and Sandstone under Impact Loadings

2012 ◽  
Vol 13 (2) ◽  
pp. 209-217
Author(s):  
Jun-Zhong Liu ◽  
Jin-Yu Xu ◽  
Xiao-Cong Lv ◽  
De-Hui Zhao ◽  
Bing-Lin Leng
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Failure Mode ◽  
Failure Modes ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Mechanical Properties ◽  
Tensile Failure ◽  
Strength Increase ◽  
Dynamic Mechanical ◽  
Rock Samples

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 .

Study of Dynamic Mechanical Properties on Cement Asphalt Mortar of High Elastic Type

2014 ◽  
Vol 1049-1050 ◽  
pp. 346-353
Author(s):  
Lei Fang ◽  
De Hua Deng ◽  
Jian Wei Peng ◽  
Yong Wang ◽  
Qing Tian
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Strain Rate ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Mechanical Properties ◽  
Experimental Result ◽  
Dynamic Mechanical ◽  
Ca Mortar ◽  
Asphalt Mortar

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.

Comparison of Dynamic Mechanical Properties between Pure Iron (BCC) and Fe-30Mn-3Si-4Al TWIP Steel (FCC)

2014 ◽  
Vol 692 ◽  
pp. 179-186
Author(s):  
Wei Ping Bao ◽  
Zhi Ping Xiong ◽  
Fu Ming Wang ◽  
Jian Shu ◽  
Xue Ping Ren
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Deformation Mechanism ◽  
Pure Iron ◽  
Twip Steel ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Mechanical Properties ◽  
Face Centered Cubic ◽  
Hopkinson Pressure Bar ◽  
Dynamic Mechanical

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.

The Temperature Dependence of the Mechanical Properties of Gamma TiAl

1994 ◽  
Vol 364 ◽  
Author(s):  
B. Viguier ◽  
J. Bonneville ◽  
K. J. Hemker ◽  
J. L. Martin
Keyword(s):  
Mechanical Properties ◽  
Flow Stress ◽  
Strain Rate ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Strain Rate Sensitivity ◽  
Rate Sensitivity ◽  
Dislocation Motion ◽  
Compression Tests ◽  
Wide Range

AbstractMechanical properties of a polycrystalline single phased γ Ti47Al51Mn2 alloy were studied by compression tests in a wide range of temperature (100 K - 1300 K). We report, in this paper, the temperature dependence of both the flow stress and its strain rate sensitivity. These dependencies show the existence of three temperature domains corresponding to different dislocation motion mechanisms. The temperature dependence of the flow stress strain rate sensitivity is compared with values measured in single crystals1.

Sign in / Sign up

Export Citation Format

Share Document