scholarly journals High Strain Rate Characterization of Shock Absorbing Materials for Landmine Protection Concepts

2003 ◽  
Vol 10 (3) ◽  
pp. 179-186 ◽  
Author(s):  
Jennifer McArthur ◽  
Christopher Salisbury ◽  
Duane Cronin ◽  
Michael Worswick ◽  
Kevin Williams
Keyword(s):  
Strain Rate ◽  
High Strain ◽  
Dynamic Testing ◽  
Stress Wave Propagation ◽  
Published Data ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars ◽  
Dynamic Material Properties ◽  
Foamed Metals

Numerical modelling of footwear to protect against anti-personnel landmines requires dynamic material properties in the appropriate strain rate regime to accurately simulate material response. Several materials (foamed metals, honeycombs and polymers) are used in existing protective boots, however published data at high strain rates is limited.Dynamic testing of several materials was performed using Split Hopkinson Pressure Bars (SHPB) of various sizes and materials. The data obtained from these tests has been incorporated into material models to predict the initial stress wave propagation through the materials. Recommendations for the numerical modeling of these materials have also been included.

scholarly journals The Off-Axis IBII Test for Composites

2020 ◽  
Author(s):  
S. Parry ◽  
L. Fletcher ◽  
F. Pierron
Keyword(s):  
Shear Modulus ◽  
Strain Rate ◽  
High Strain ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Published Data ◽  
Shear Moduli ◽  
Test Methodology ◽  
Split Hopkinson

Abstract Composite components regularly experience dynamic loads in service. Despite this, it is still difficult to obtain accurate mechanical properties of composite materials under high strain rate conditions. In this study, a new application of the Image-Based Inertial Impact (IBII) test methodology was developed, to generate an accurate in-plane transverse and shear moduli dataset from unidirectional (UD) off-axis composite specimens. The obtained dataset was consistent across different sample configurations, where results from the UD45$$^{\circ }$$ ∘ off-axis specimens agreed well with the UD90$$^{\circ }$$ ∘ values. Validation of the shear modulus identification was also undertaken by comparing the results from the UD90$$^{\circ }$$ ∘ and UD45$$^{\circ }$$ ∘ specimens with a multi-directional (MD) configuration. Here, it was found that MD±45$$^{\circ }$$ ∘ specimen shear modulus values where marginally lower than that from the UD specimens, in accordance with the lower fibre volume fraction of the MD laminate. Low strain rate sensitivities in the $$0.5-2\times$$ 0.5 - 2 × 10$$^{3}$$ 3  $$\hbox {s}^{-1}$$ s - 1 regime evidenced in this work suggest previously published data (often from split-Hopkinson bar tests) may include both a material and system i.e. testing apparatus response.

A Numerical Investigation into the Tensile Split Hopkinson Pressure Bars Test for Sheet Metals

2013 ◽  
Vol 421 ◽  
pp. 464-467 ◽  
Author(s):  
Thanh Nam Pham ◽  
Hyo Seong Choi ◽  
Jong Bong Kim
Keyword(s):  
Flow Stress ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Finite Element Analyses ◽  
Compressive Flow ◽  
Design Guide ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars

Determination of theflow stress of materials at high strain rate is very important in automotive and military areas.The compressive flow stress at high strain rate can be obtained relativelyexactly by SHPB(Split Hopkinson Pressure Bars) tests. However, it is difficult to determinethe flow stressexactlyin the tensile state by using the SHPB tests. The difficulty in the tensile SHPB tests is how to fix a specimen on two bars. So, the design of a specimen and holders is needed to obtain more accurate measurement of the flow stress. In this study, the accuracy of the tensile SHPB tests results was numerically investigated. Finite element analyses of the tensile SHPB were carried out for various cases of fixing bolt location and bolting force. From the analysis results, a design guide for the fixing structure was obtained and the causes of error were investigated.

The Effect of Strain Rate on the Material Characteristics of Nickel-Based Superalloy Inconel 718

2007 ◽  
Vol 340-341 ◽  
pp. 283-288 ◽  
Author(s):  
Jung Han Song ◽  
Hoon Huh
Keyword(s):  
Dynamic Response ◽  
High Strain Rate ◽  
Strain Rate ◽  
Turbine Blade ◽  
Inconel 718 ◽  
High Speed ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Experimental Results ◽  
Stress Wave Propagation

The dynamic response of the turbine blade materials is indispensable for analysis of erosions of turbine blades as a result of impulsive loading associated with gas flow. This paper is concerned with the dynamic material properties of the Inconel 718 alloy which is widely used in the high speed turbine blade. The dynamic response at the corresponding level of the strain rate should be acquired with an adequate experimental technique and apparatus due to the inertia effect and the stress wave propagation. In this paper, the dynamic response of the Inconel 718 at the intermediate strain rate ranged from 1/s to 400/s is obtained from the high speed tensile test and that at the high strain rate above 1000/s is obtained from the split Hopkinson pressure bar test. The effects of the strain rate on the dynamic flow stress, the strain rate sensitivity and the failure elongation are evaluated with the experimental results. Experimental results from both the quasi-static and the high strain rate up to 3000/s are interpolated in order to construct the constitutive relation that should be applied to simulate the dynamic behavior of the turbine blade made of the Inconel 718.

Dynamic Behaviors of near β-Type Ti-5Al-5Mo-5V-3Cr Titanium Alloys under High Strain Rate

2015 ◽  
Vol 816 ◽  
pp. 795-803
Author(s):  
Yan Ling Wang ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Rui Liu
Keyword(s):  
Strain Rate ◽  
Titanium Alloys ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Failure Behavior ◽  
Hopkinson Pressure Bar ◽  
Fracture Failure ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Dynamic Loading Conditions

The mechanical properties and fracture failure behavior of the near β-type Ti-5Al-5Mo-5V-3Cr-X (X = 1Fe or 1Zr) titanium alloys were studied by Split Hopkinson Pressure Bar (SHPB) experiment under the dynamic loading conditions at a strain rate of 1.5 × 103 s-1–5.0 × 103 s-1. Results showed that the SHPB specimen fractured in the direction of maximum shearing stress at an angle of 45° with the compression axis. The fracture surface revealed the shear and tension zones with cleavage steps and parabolic dimples. Severe early unloading was observed on the Ti-5553 alloy under a strain rate of 4,900 s-1 loading condition, and the dynamic property of the Ti-55531Zr alloy was proved to be the optimal.

Tensile Ductility of Ultra-Fine Grained Copper at High Strain Rate

2010 ◽  
Vol 160-162 ◽  
pp. 260-266 ◽  
Author(s):  
Tao Suo ◽  
Kui Xie ◽  
Yu Long Li ◽  
Feng Zhao ◽  
Qiong Deng
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Testing Machine ◽  
Coarse Grained ◽  
Dislocation Dynamic ◽  
Pressing Method ◽  
Fine Grained ◽  
Angular Pressing ◽  
Split Hopkinson

In this paper, ultra-fine grained copper fabricated by equal channel angular pressing method and annealed coarse grained copper were tensioned under both quasi-static and dynamic loading conditions using an electronic universal testing machine and the split Hopkinson tension bar respectively. The rapture surface of specimen was also observed via a Scanning Electron Microscope (SEM). The experimental results show that the ductility of polycrystalline copper decreases remarkably due to the grain refinement. However, with the increase of applied strain rate, ductility of the UFG-Cu is enhanced. The fracture morphologies also give the evidence of enhanced ductility of UFG-Cu at high strain rate. It is believed the enhanced ductility of UFG materials at high strain rate can be attributed to the restrained dislocation dynamic recovery.

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