Analysis and assessment of electromagnetic ring expansion as a high‐strain‐rate test

1989 ◽  
Vol 65 (2) ◽  
pp. 411-422 ◽  
Author(s):  
William H. Gourdin
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Ring Expansion ◽  
Rate Test ◽  
High Strain Rate Test

Plastic flow behavior of 7017 and 7055 aluminum alloys under different high strain rate test methods

2014 ◽  
Vol 612 ◽  
pp. 343-353 ◽  
Author(s):  
Bidyapati Mishra ◽  
Chandan Mondal ◽  
Rajnish Goyal ◽  
Partha Ghosal ◽  
K. Siva Kumar ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
High Strain Rate ◽  
Strain Rate ◽  
Plastic Flow ◽  
High Strain ◽  
Flow Behavior ◽  
Test Methods ◽  
Rate Test ◽  
High Strain Rate Test

scholarly journals Suitability of the electromagnetic ring expansion test to characterize materials under high strain rate deformation

2016 ◽  
Vol 80 ◽  
pp. 15002
Author(s):  
Kang Yang ◽  
Geoffrey Taber ◽  
Thaneshan Sapanathan ◽  
Anupam Vivek ◽  
Glenn S Daehn ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Ring Expansion ◽  
Expansion Test ◽  
High Strain Rate Deformation

High Strain Rate Test of a Steel Plate under Blast Loading from High Explosive

2013 ◽  
Vol 767 ◽  
pp. 144-149 ◽  
Author(s):  
Tei Saburi ◽  
Shiro Kubota ◽  
Yuji Wada ◽  
Tatsuya Kumaki ◽  
Masatake Yoshida
Keyword(s):  
Strain Rate ◽  
Dynamic Stress ◽  
Steel Plate ◽  
High Strain ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Time Deformation ◽  
Rate Test ◽  
High Strain Rate Test

In this study, a high strain rate test method of a steel plate under blast loading from high explosive was designed and was conducted by a combined experimental/numerical approach to facilitate the estimation process for the dynamic stress-strain curve under practical strain rate conditions. The steel plate was subjected to a blast load, which was generated by Composition C4 explosive and the dynamic deformation of the plate was observed with a high-speed video camera. Time-deformation relations were acquired by image analysis. A numerical simulation for the dynamic behaviors of the plate identical to the experimental condition was conducted using a coupling analysis of finite element method (FEM) and discrete particle method (DPM). Explosives were modeled by discrete particles and the steel plate and other materials were modeled by finite element. The blast load on the plate was described fluid-structure interaction (FSI) between DPM and FEM. As inverse analysis scheme to estimate dynamic stress-strain curve, an evaluation using a quasistatic data was conducted. In addition, two types of approximations for stress-strain curve were assumed and optimized by least square method. One is a 2-piece approximation, and was optimized by least squares method using a yield stress and a tangent modulus as parameters. The other is a continuous piecewise linear approximation, in which a stress-strain curve was divided into some segments based on experimental time-deformation relation, and was sequentially optimized using youngs modulus or yield stress as parameter. The results showed that the piecewise approximation can gives reasonably agreement with SS curve obtained from the experiment.

scholarly journals Intermediate Strain Rate Testing Devices

2020 ◽  
Author(s):  
Trunal Bhujangrao
Keyword(s):  
Experimental Data ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Full Range ◽  
Strain Rates ◽  
Intermediate Strain Rate ◽  
Wide Range ◽  
Rate Testing ◽  
Rate Test

The existing experimental tests are mainly designed to study the mechanical response of materials at various strain rates. Many researchers performed the experimental test in tension, compression, and shear (with torsion test) over a wide range of strain rates. They found out that material exhibits an increase in yield stress as well as flows stress with an increase in strain rate. It illustrates that there is a need for experimental data to study the material behaviour over the full range of strain rates, from quasi-static to high strain rate test. Many special techniques have been developed to bridge the strain rate gap between quasi-static and high strain rate testing to provide a method for an intermediate strain rate test for engineering materials. Some researchers have tried to conduct intermediate strain rate tests with standard servo-hydraulic load frames. However, the results of such tests are not accurate. The problem is that during the experiment, the whole machine is not in static equilibrium. The inertial effect influences the experimental data. The records obtained from these machines are often noisy with large oscillation. therefore, the comprehensive review is given to describes the development and evolution of the existing intermediate strain rate testing devices which includes the working principles, some critical theories, technological innovation in load measurement techniques, components of the device, basic technical assumption, and measuring techniques. In addition, some research direction on future implementation and development of an intermediate strain rate apparatus is also discussed in detail.

Development of Electromagnetic Ring Expansion Apparatus for High-Strain-Rate Test

2009 ◽  
Vol 147-149 ◽  
pp. 645-650 ◽  
Author(s):  
Jacek Janiszewski ◽  
Wiesław Pichola
Keyword(s):  
High Strain ◽  
Capacitor Bank ◽  
Ring Expansion ◽  
Initial Charge ◽  
Rate Test ◽  
High Strain Rate Test ◽  
Preliminary Experimental Data ◽  
Set Up ◽  
Impulse High Voltage ◽  
Copper Ring

The structure of the experimental set-up for electromagnetic ring expansion and its electric properties are presented in the paper. While earlier expanding ring apparatuses were usually equipped with shaped-charge, thyratron or ignitron switches, we propose to use the impulse high-voltage thyritor as a switch to discharge capacitor bank. Furthermore, the preliminary results of the copper ring fragmentation properties are presented for different initial charge of capacitor bank (0,5 ÷ 2 kV). On the basis of our calculated and preliminary experimental data of the ring motion for expansion at 2 kV, we estimated the radial ring velocity, which was close to 250 m/s.

Identification of optimized constitutive model parameters at a high strain rate using electromagnetic ring expansion test results

2011 ◽  
Vol 225 (4) ◽  
pp. 781-789 ◽  
Author(s):  
M Sedighi ◽  
M Khandaei ◽  
H Shokrollahi
Keyword(s):  
Experimental Data ◽  
Constitutive Model ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Optimization Procedure ◽  
Ring Expansion ◽  
Model Parameters ◽  
Test Results ◽  
Expansion Test

In this article, parameters of the material constitutive model have been identified at high strain rate electromagnetic ring expansion test using experimental data taken from literature for oxygen-free electronic copper (OFE Cu). The experimental data were processed using a finite-element optimization procedure in which the measured deformation has been applied to a specimen. An optimal set of material constants for JohnsonCook constitutive model have been computed by minimizing the standard deviation of differences between experimental and calculated stressstrain curves. The applicability of identified parameters has been validated successfully by using simulation of reverse Taylor impact test results. The presented method in this article was found to be an effective method for identifying the material model parameters at high strain rates.

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