Stress Wave Propagation for Nonlinear Viscoelastic Polymeric Materials at High Strain Rates

2003 ◽  
Vol 19 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Li-Lih Wang
Keyword(s):  
Wave Propagation ◽  
High Frequency ◽  
High Strain ◽  
Polymeric Materials ◽  
Elastic Response ◽  
Stress Wave Propagation ◽  
Strain Rates ◽  
High Strain Rates ◽  
Nonlinear Viscoelastic ◽  
The Impact

ABSTRACTWithout knowing the dynamic constitutive relation of materials under high strain rates, no wave propagation can be correctly analyzed. A Series of experimental and theoretical investigation at high strain rates revealed that the nonlinear viscoelastic behavior of polymers and the related composites are well described by the Zhu-Wang-Tang (ZWT) nonlinear viscoelastic constitutive equation. The impulsive reponse of ZWT materials consists of a rate independent nonlinear elastic response and a high frequency linear viscoelastic response. The dispersion and attenuation of nonlinear viscoelastic waves mainly depend on the effective nonlinearity and the high frequency relaxation time θ2. An “effective influence distance” or “effective influence time” is defined to characterize the wave propagation range where θ2 dominates the impact relaxation process.

Design Issues of a Kolsky Tension Bar

2013 ◽  
Vol 535-536 ◽  
pp. 477-480
Author(s):  
Renato R.V. Neves ◽  
Marcilio Alves
Keyword(s):  
Wave Propagation ◽  
High Strain ◽  
Strain Rates ◽  
Design Phase ◽  
Design Issues ◽  
High Strain Rates ◽  
Tensile Wave ◽  
Structural Impact ◽  
Material Sample ◽  
Kolsky Tension Bar

In general, materials exhibit an increase of strength when loaded at high strain rates, which should be taken into account when dealing with structural impact. Kolsky developed an equipment operating based on elastic wave propagation capable of submitting a material sample to high strain rates. This paper presents some design features of such a tensile wave machine, including mechanical and electronic design issues, which may be helpful in a design phase.

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 Impact Tensile Behaviors of PVDF Building Coated Fabrics

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Lianqiong Zheng ◽  
Yilong Ye ◽  
Jinping zhuang ◽  
Yongqian Zheng
Keyword(s):  
Energy Absorption ◽  
High Strain ◽  
Absorption Capacity ◽  
Strain Rates ◽  
Membrane Structures ◽  
High Strain Rates ◽  
Stress Strain ◽  
Strain Relationship ◽  
Coated Fabrics ◽  
The Impact

The paper presents the impact tensile behaviors of two common building membranes (Ferrari 1002T2 membrane and XYD 300N membrane) in PVDF-coated-fabric membrane structures. The tests are conducted using the split Hopkinson bar test device. Typical forms of stress and strain are applied for comparing the stress-strain relationship between quasi-static and high strain rates. Besides, the failure mechanism and energy absorption at high strain rates are discussed. The results show that with the increase of strain rates, the growth rate of the stress of PVDF membrane decreases gradually, which is different from the stress-strain relationship in low strain rates. At high strain rates, the ultimate tensile strength increases linearly with the increase of strain rates. In addition, the energy absorption capacity of the material increases with the increase of strain rates. The results can provide an important basis for the design and analysis of membrane structures under the impact loads.

Research on the Mechanical Behavior of Styropor Concrete at High Strain Rates

2010 ◽  
Vol 168-170 ◽  
pp. 2086-2091
Author(s):  
Ze Bin Hu ◽  
Jin Yu Xu ◽  
Jie Zhu ◽  
Qiang He ◽  
Gang Li ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
High Strain ◽  
Dynamic Strength ◽  
Strain Rates ◽  
Average Strain ◽  
High Strain Rates ◽  
Average Strain Rate ◽  
The Impact

Mechanical behavior of Styropor concrete(EPSC) added with various volumetric fractions of EPS subjected to high strain rates were studied by using the Large-Diameter-SHPB. The infection of volumetric fractions and average strain rate to dynamic properties of EPSC were investigated. The experimental results show that under high strain rate condition, the dynamic strength, dynamic strength increase factor(DIF) and limit strain of EPSC are strain rate dependent, the strain rate effect can be expressed by linear approximations, and the relationship between elastic modulus and average strain rate is independent.With the addition of volumetric fractions of EPS, the impact compressive strength and elastic modulus of EPSC declines, and the toughness of EPSC is reinforced.

Dynamic Characteristics of the Sinter-Forged Cu-Cr Alloys with the Variation of Chrome Content

2006 ◽  
Vol 116-117 ◽  
pp. 255-258
Author(s):  
Jung Han Song ◽  
Hoon Huh
Keyword(s):  
Dynamic Response ◽  
Dynamic Characteristics ◽  
High Speed ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Impact Behavior ◽  
Stress Wave Propagation ◽  
Strain Rates ◽  
High Strain Rates

This paper is concerned with the dynamic characteristics of sinter-forged Cu–Cr alloy for various strain-rates. The amount of the chrome content is varied from 10 %wt to 30 %wt in order to investigate the influence of the chrome content on the dynamic characteristics. The dynamic response at the corresponding level of strain-rate should be obtained with an adequate experimental technique and corresponding apparatus due to the inertia effect and the stress wave propagation. In this paper, the high speed tensile testing machine is utilized in order to identify the dynamic response of the Cu–Cr alloy at the intermediate strain-rates and the split Hopkinson pressure bar is used at the high strain-rates. Experimental results from both the quasi-static and the high strain-rates up to the 5000/s are interpolated with respect to the amount of the chrome content in order to construct the Johnson–Cook and the modified Johnson–Cook model as the constitutive relation for numerical simulation of the dynamic impact behavior of electrodes.

Understanding the impact response of lead-free solder at high strain rates

2020 ◽  
Vol 172 ◽  
pp. 105416
Author(s):  
Xu Long ◽  
Junmeng Xu ◽  
Shaobin Wang ◽  
Wenbin Tang ◽  
Chao Chang
Keyword(s):  
High Strain ◽  
Impact Response ◽  
Lead Free ◽  
Strain Rates ◽  
Lead Free Solder ◽  
High Strain Rates ◽  
Free Solder ◽  
The Impact

scholarly journals Dynamic Tensile Testing of Needle-Punched Nonwoven Fabrics

2020 ◽  
Vol 10 (15) ◽  
pp. 5081
Author(s):  
Francisca Martínez-Hergueta ◽  
Antonio Pellegrino ◽  
Álvaro Ridruejo ◽  
Nik Petrinic ◽  
Carlos González ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Tensile Testing ◽  
High Speed ◽  
High Strain ◽  
Nonwoven Fabric ◽  
Image Correlation ◽  
High Speed Photography ◽  
Strain Rates ◽  
High Strain Rates ◽  
Nonwoven Fabrics

The tensile testing of a needle-punched nonwoven fabric is presented. A high-sensitivity Split-Hopkinson Tensile Bar device was specifically designed for this purpose. The strain gauge measurements were combined with high-speed photography and Digital Image Correlation to analyse the deformation micromechanisms at high strain rates. The experimental set-up allowed to determine the wave propagation velocity of the as-received nonwove fabric, the evolution of the strain field with deformation and the wave interaction inside the fabric. The deformation was accommodated by the same micromechanisms observed during quasi-static tensile testing and ballistic impact, which comprised fibre straightening, rotation and sliding. Heterogeneous strain fields were developed in the nonwoven fabric as a result of the non-linear pseudoplastic response of the fabric and the internal dissipation due to the frictional deformation micromechanisms, preventing the propagation of high magnitude strain waves into the specimen. Additionally, the output forces were analysed to determine the influence of high-strain rates in the mechanical response of the nonwoven fabric, finding an increment of the stiffness for low applied strains under dynamic loading. These findings provide the basis to develop strain-rate dependent constitutive models to predict wave propagation in needle-punched nonwoven fabrics when subjected to impact loads.

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