scholarly journals Behavior of high-density polyethylene at high strain rates

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Jan Trnka ◽  
Eva Nezbedová ◽  
Jan Kober ◽  
Jaroslav Buchar
Keyword(s):  
Experimental Data ◽  
Detailed Analysis ◽  
Frequency Domain ◽  
Linear Viscoelasticity ◽  
High Density Polyethylene ◽  
High Strain ◽  
Strain Rates ◽  
High Strain Rates ◽  
Permanent Strain ◽  
Pressure Bar

The Hopkinson split pressure bar (HSPB) was used for the testing of three polymers at strain rates between 102 to 103 s-1. Higher strain rates were achieved using the direct Hopkinson test. Experimental data were evaluated in time as well as in the frequency domain. A more detailed analysis in the frequency domain showed that the description of tested polymers can be described in the framework of the linear viscoelasticity. The use of the direct Hopkinson test showed the occurrence of a permanent strain.

Evolution of Anand Parameters With Elevated Temperature Aging for SAC Leadfree Alloys

2020 ◽  
Author(s):  
Pradeep Lall ◽  
Vikas Yadav ◽  
Jeff Suhling ◽  
David Locker
Keyword(s):  
Experimental Data ◽  
High Strain ◽  
Constitutive Models ◽  
Tensile Tests ◽  
Model Parameters ◽  
Strain Rates ◽  
Automotive Electronics ◽  
High Strain Rates ◽  
Operating Temperatures ◽  
Electronic Assemblies

Abstract Electronic equipment in automotive, agricultural and avionics applications may be subjected to temperatures in the range of −55 to 200°C during storage, operation and handling in addition to high strain-rates. Strain rates in owing to vibration and shock may range from 1–100 per sec. Temperature in electronic assemblies depends typically on location, energy dissipation and thermal architecture. Some investigators have indicated that the required operating temperature is between −40 to 200°C for automotive electronics located underhood, on engine, on transmission. Prior data indicates the evolution of mechanical properties under extended exposures to high temperatures. However, the constitutive models are often only available for pristine materials only. In this paper, effect of low operating temperatures (−65°C to 0°C) on Anand-model parameters at high strain rates (10–75 per sec) for aged SAC (SAC105 and SAC-Q) solder alloys has been studied. Stress-Strain curves have been obtained at low operating temperatures using tensile tests. The SAC leadfree solder samples were subjected to isothermal-aged up to 4-months at 50°C before testing. Anand Viscoplastic model has been used to describe the material constitutive behavior. Evolution of Anand Model parameters for SAC solder has been investigated. The computed parameters of the experimental data were used to simulate the tensile test and verified the accuracy of the model. A good correlation was found between experimental data and Anand predicted data.

Using Split Hopkinson Pressure Bars to Perform Large Strain Compression Tests on Neoprene at Intermediate and High Strain Rates

2013 ◽  
Vol 631-632 ◽  
pp. 458-462 ◽  
Author(s):  
Peng Duo Zhao ◽  
Yu Wang ◽  
Jian Ye Du ◽  
Lei Zhang ◽  
Zhi Peng Du ◽  
...  
Keyword(s):  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Large Strain ◽  
Rate Sensitivity ◽  
Strain Rates ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
High Strain Rates ◽  
Split Hopkinson ◽  
Pressure Bar

The strain rate sensitivity of neoprene is characterized using a modified split Hopkinson pressure bar (SHPB) system at intermediate (50 s-1, 100 s-1) and high (500 s-1, 1000 s-1) strain rates. We used two quartz piezoelectric force transducers that were sandwiched between the specimen and experimental bars respectively to directly measure the weak wave signals. A laser gap gage was employed to monitor the deformation of the sample directly. Three kinds of neoprene rubbers (Shore hardness: SHA60, SHA65, and SHA70) were tested using the modified split Hopkinson pressure bar. Experimental results show that the modified apparatus is effective and reliable for determining the compressive stress-strain responses of neoprene at intermediate and high strain rates.

Evaluation of Dynamic Properties of Wood-Plastic Composites Using Split Hopkinson Bar Methods

2016 ◽  
Vol 715 ◽  
pp. 23-26
Author(s):  
Masahiro Nishida ◽  
Shun Furuya ◽  
Hirokazu Ito ◽  
Rie Makise ◽  
Masaki Okamoto
Keyword(s):  
High Strain ◽  
Dynamic Properties ◽  
Wood Flour ◽  
Impact Resistance ◽  
Strain Rates ◽  
High Strain Rates ◽  
Wood Plastic Composites ◽  
Plastic Composites ◽  
Pressure Bar ◽  
The Impact

Wood-plastic composites (WPCs) which consist of wood flour and plastics have been widely used as architectural materials for a long time. However, the impact resistance is not always high and basic mechanical properties at high strain rate are not fully understood. In order to clarify the tensile behavior at high strain rates, split Hokinson pressure bar method was used for WPCs consisting of polypropylene. The effects of mixing ratio on the maximum stress and elongation at break were examined at high strain rates.

scholarly journals Measurements of Shearing Property of High N Alloy Steel at Super High Strain Rates

2011 ◽  
Vol 413 ◽  
pp. 42-45
Author(s):  
Xiao An Chen ◽  
Shun Cheng Song ◽  
Ting Hui Wang
Keyword(s):  
Alloy Steel ◽  
High Strain ◽  
Dislocation Dynamics ◽  
Constitutive Relationship ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
High Strain Rates ◽  
Alloy Steels ◽  
Pressure Bar ◽  
Dynamic Shearing

In order to obtain the dynamic shearing property of high N alloy steel, the plugging test was performed by using the improved Hopkinson pressure bar system. As dynamic shearing strengths, the dynamic shearing energies during plugging process of two type high N alloy steels were determined from the shearing constitutive relationship at different super high strain rates. According to the theory of dislocation dynamics in Seeger equation, a dynamic shearing damage constitutive relationship was established and the different parameters of this material were determined by using the curve fitting method. The measured results indicated that the dynamic shearing property of high N alloy steel could be obtained effectively by the improved Hopkinson pressure bar system, and the effects of strain rate could be simulated by dynamic shearing damage constitutive relationship.

Deformation Behavior of Ti-6Al-4V-0.1B Alloy Loaded under High Strain Rates

2016 ◽  
Vol 849 ◽  
pp. 266-270 ◽  
Author(s):  
Yang Yu ◽  
Qi Gao ◽  
Xun Jun Mi ◽  
Song Xiao Hui ◽  
Wen Jun Ye
Keyword(s):  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
High Strain Rates ◽  
The Matrix ◽  
Split Hopkinson ◽  
Pressure Bar

Deformation and fracture behaviors of Ti-6Al-4V-0.1B alloy with Widmanstätten, equiaxed and bimodal microstructures were investigated by Split Hopkinson Pressure Bar (SHPB) under high strain rates of 2100-3200 s-1. The results showed that the equiaxed and bimodal structures had a higher bearing capacity at high strain rates than that of the Widmanstätten structure. With the same microstructure, the increase of strain rate gave rise to an improved uniform plastic deformation. According to an observation on the deformed microstructure, it was found that adiabatic shear behavior was the main reason for failure and fracture of the alloy. The formation and propagation of adiabatic shear bands (ASBs) was the precursor for the failure and fracture of the material. Cavities at the interface between TiB phase and the matrix readily formed due to the uncoordinated deformation, which are not the dominate reason for the failure and fracture.

scholarly journals The Mechanical Properties and the Influence of Parameters for Metallic Closed-Cell Foam Subjected to High-Strain Rates

2015 ◽  
Vol 1119 ◽  
pp. 799-806
Author(s):  
Charles E. Lord ◽  
Zhen Huang
Keyword(s):  
Mechanical Properties ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Metallic Foam ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
High Strain Rates ◽  
Closed Cell ◽  
Pressure Bar ◽  
Cell Foam

As the trend for lighter more efficient structures continues, the requirement for alternative materials follows. One material that has gained attention more recently is porous metallic foam. One drawback to these materials is that there is limited pedigree and understanding of their performance. As with all materials, the use of metallic foam for structures requires knowledge of its mechanical properties; including at high-strain rates. The focus of this paper is to determine the compressive mechanical properties and the influencing parameters for AISI 4340 steel closed-cell foam under high-strain rates (776s-1 to 3007s-1). ANSYS commercial finite element code is used to simulate a closed-cell sample under a split Hopkinson pressure bar test. In this paper the pores are considered to be spherical in shape for simplification while various parameters such as the pore size, the number of pores, the distribution of pores, and the strain rate are varied. Each of these parameters gives this material a unique response which is presented in this paper.

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