Evaluation of the Material Properties of an OFHC Copper Film at High Strain Rates Using a Micro-Testing Machine

2010 ◽  
Vol 51 (6) ◽  
pp. 845-855 ◽  
Author(s):  
J. S. Kim ◽  
H. Huh
Keyword(s):  
Material Properties ◽  
High Strain ◽  
Testing Machine ◽  
Copper Film ◽  
Ofhc Copper ◽  
Strain Rates ◽  
High Strain Rates

scholarly journals Modelling and simulation of dynamic recrystallization (DRX) in OFHC copper at very high strain rates

2017 ◽  
Author(s):  
G. Testa ◽  
N. Bonora ◽  
A. Ruggiero ◽  
G. Iannitti ◽  
I. Persechino ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
High Strain ◽  
Modelling And Simulation ◽  
Ofhc Copper ◽  
Strain Rates ◽  
High Strain Rates ◽  
Very High

Mechanical Behavior of Advanced High Strength Steel at High Strain Rates

2011 ◽  
Vol 82 ◽  
pp. 178-183 ◽  
Author(s):  
Nilamber Kumar Singh ◽  
Ezio Cadoni ◽  
Maloy K. Singha ◽  
Narinder K. Gupta
Keyword(s):  
Mechanical Behavior ◽  
High Strength Steel ◽  
High Strain ◽  
Testing Machine ◽  
High Strength ◽  
Strain Rates ◽  
Advanced High Strength Steel ◽  
High Strain Rates ◽  
Loading Rates ◽  
Universal Testing

This paper presents the mechanical behavior of advanced high strength steel, Dual Phase 1200 steel (DP1200) at high strain rates (250s-1- 750s-1) under tensile loading. The mechanical behavior of materials depends on the loading rates. The accurate knowledge of the mechanical behavior of materials at high strain rates is essential in order to improve the safety against crash, impacts and blast loads. High strain rate experiments are performed on modified Hopkinson bar (MHB) apparatus; however, some quasi-static (0.001s-1) tests are also conducted on electromechanical universal testing machine at tensile loads. Based on the experimental results, the material parameters of the existing Cowper-Symonds and Johnson-Cook models are determined. These models fit the experimental data well and hence can be recommended for the numerical simulation of the problems involving this material at high strain rates.

scholarly journals Size Dependence and Dynamic Properties of Adobe Masonry Bricks tested at high strain rates

2021 ◽  
Vol 250 ◽  
pp. 06002
Author(s):  
T. Li Piani ◽  
J. Weerheijm ◽  
M. Peroni ◽  
L.J. Sluys
Keyword(s):  
Material Properties ◽  
Size Dependence ◽  
High Strain ◽  
Research Centre ◽  
Experimental Program ◽  
Relevant Parameter ◽  
Strain Rates ◽  
High Strain Rates ◽  
Hydraulic Machines

Masonry is a construction technique which typically reacts in compression. Characterization of its material properties in compression is thus of paramount importance. This especially counts for adobe bricks because their material properties are still unknown to a large extent. This traditional masonry, made of locally available soil and fibres, is spread in areas currently involved in military conflicts, where also European forces operate. Therefore, not only its static properties in compression, but even more the dynamic strength is a relevant parameter. Laboratory characterization of material properties still pose several challenges, among which so-called size dependence is one of the most controversial topics. This entails the possible variation of material properties values from tests on specimens of different size and shape. Several factors may concur to its determination and a well-founded theory does not exist yet. This counts for statics and even more in dynamics. Addressing the properties in compression of bricks at high strain rates is rare, namely no studies of size dependence on masonry bricks in dynamic regimes are published. Lately, a series of experimental campaigns were conducted by the authors at the Joint Research Centre of the European Commission. In these campaigns, a series of compression tests were performed on several types of adobe bricks. Different soil mixtures were used to produce cylindrical samples of different sizes. Compressive tests from 2e-5 s-1 to 10 s-1 and 100 s-2 were executed using hydraulic machines as well as split Hopkinson bars. Next, the static as well as the dynamic material properties as calculated from tests on specimens of different sizes and material compositions have been qualitatively and quantitatively compared and interpreted. In this paper, the experimental program is presented, next the material properties in strength and ductility as well as the dynamic increase factors are investigated.

Modelling of the Ship Structural Ballistic Shields from the 10GHMBA Steel

2011 ◽  
Vol 180 ◽  
pp. 303-312
Author(s):  
Wojciech Jurczak ◽  
Lesław Kyzioł
Keyword(s):  
High Strain ◽  
Terrorist Attack ◽  
Testing Machine ◽  
Impact Testing ◽  
Strain Rates ◽  
High Strain Rates ◽  
Critical Elements ◽  
Hull Structure ◽  
Ballistic Pendulum ◽  
Protective Structures

The contemporary protective structures are now critical elements of the floating units, military, public and other objects. Their task is to weaken the effects of a terrorist action against selected areas with the use of explosives or projectiles. The knowledge of material behaviour at high strain rates is essential for designing the ballistic shields. The hull external shells of the Polish Navy ships now in service do not meet the requirements of ballistic anti-terrorist shields against small arms shooting or the rocket and shell splinters. This is a significant problem in the case of defending a ship against terrorist attack threats. Therefore, there is a tendency for building internal and external ballistic shields in the ship hull structure to protect the critical compartments and action stations. The paper presents investigations of materials subjected to high strain rates, with the 10GHMBA E-620 bainitic steel as an example. The experiments were carried out on the MTS 810.12 testing machine, rotary impact testing hammer, the Taylor test stand and on the ballistic pendulum. In the final part of the paper, some numerical simulations are presented allowing to analyse the fast-changing processes arising during loading the structure by an impact of high velocity bodies.

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.

Material Behaviors of PBX Simulant with Various Strain Rates

2013 ◽  
Vol 535-536 ◽  
pp. 117-120 ◽  
Author(s):  
Chung Hee Park ◽  
Seh Wan Jeong ◽  
Hoon Huh ◽  
Jung Su Park
Keyword(s):  
Strain Hardening ◽  
High Speed ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Materials Testing ◽  
Strain Rates ◽  
High Strain Rates ◽  
Material Behaviors ◽  
Compressive Tests

This paper is concerned with the material behaviors of PBX(Polymer Bonded eXplosive) simulant at various strain rates ranging from 0.0001/sec to 3150/sec. Material behaviors of PBX at the high strain rates are important in the prediction of deformation modes of PBX in a warhead which undergoes severe impact loading. Inert PBX stimulant which has analogous material behaviors with PBX was utilized for material tests due to safety issues. Uniaxial compressive tests at quasi-static and intermediate strain rates were conducted with cylindrical specimen using a dynamic materials testing machine, INSTRON 8801. Uniaxial compressive tests at high strain rates ranging from 1200/sec to 3150/sec were conducted using a split Hopkinson pressure bar. Deformation behaviors were investigated using captured images obtained from a high-speed camera. The strain hardening behaviors of PBX simulant were formulated by proposed strain rate-dependent strain hardening model.

Characterization of Hardening Behavior at Ultra-High Strain Rate, Large Strain, and High Temperature

2016 ◽  
Vol 725 ◽  
pp. 138-142
Author(s):  
Ming Jun Piao ◽  
Hoon Huh ◽  
Ik Jin Lee
Keyword(s):  
High Temperature ◽  
High Strain ◽  
Large Strain ◽  
Thermal Softening ◽  
Ofhc Copper ◽  
Strain Rates ◽  
High Strain Rates ◽  
Softening Effect ◽  
Wide Range

This paper is concerned with the characterization of the OFHC copper flow stress at strain rates ranging from 10−3 s−1 to 106 s−1 considering the large strain and high temperature effects. Several uniaxial material tests with OFHC copper are performed at a wide range of strain rates from 10−3 s−1 to 103 s−1 by using a INSTRON 5583, a High Speed Material Testing Machine (HSMTM), and a tension split Hopkinson pressure bar. In order to consider the thermal softening effect, tensile tests at 25°C and 200°C are performed at strain rates of 10−3 s−1,101 s−1, and 102 s−1. A modified thermal softening model is considered for the accurate application of the thermal softening effect at high strain rates. The large strain behavior is challenged by using the swift power law model. The high strain rates behavior is fitted with the Lim–Huh model. The hardening curves are evaluated by comparing the final shape of the projectile from numerical simulation results with the Taylor impact tests.

scholarly journals Experimental characterization of dynamic deformation behaviour for SCM440 steel at high strain rates

2018 ◽  
Vol 183 ◽  
pp. 02019
Author(s):  
Keunho Lee ◽  
Yerim Lee ◽  
Sanghyun Woo ◽  
Changsoo Lee ◽  
Leeju Park
Keyword(s):  
High Strain ◽  
Dynamic Deformation ◽  
Deformation Behaviour ◽  
Testing Machine ◽  
Experimental Tests ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
High Strain Rates

The dynamic deformation behaviours of SCM 440 steel were characterized at the strain rates from 10-3 s-1 to 106 s-1. The uniaxial tensile tests at different temperature of 25 °C, 350 °C, and 700 °C were performed by a hydraulic universal testing machine equipped with a heating stage, and the compressive tests were conducted by using a spilt Hopkinson pressure bar (SHPB) at room temperature. Material coefficients of the Johnson-Cook constitutive model considering temperature effects were obtained based on the stressstrain relations from the experimental tests. In addition, Taylor impact tests on the SCM 440 steel were carried out to evaluate the accuracy of the determined material coefficients and characterize the dynamic behavior at the ultra-high strain rates and high temperature, by comparison with numerical simulations.

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