Dynamic Constitutive Behavior and Fracture of Lanthanum Metal Subjected to Impact Compression at Different Temperatures and Impact Tension

2013 ◽  
Vol 14 (1) ◽  
pp. 15-26
Author(s):  
Huanran Wang ◽  
Canyuan Cai ◽  
Danian Chen ◽  
Dongfang Ma
Keyword(s):  
Constitutive Equation ◽  
Split Hopkinson Pressure Bar ◽  
Compressive Loading ◽  
Tensile Loading ◽  
Tensile Tests ◽  
Test System ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Impact Compression ◽  
Split Hopkinson

Abstract Based on compressive tests, static on 810 material test system (MTS) and dynamic on the first compressive loading in split Hopkinson pressure bar (SHPB) tests at different strain rates and temperatures for Lanthanum (La) cylinder specimens, this study determined Johnson-Cook (J-C) type compressive constitutive equation of La metal. The determined compressive constitutive equation of La metal was calibrated in numerically simulating the recorded large deformations of La cylinder specimens generated by the multi-compressive loadings in SHPB tests. Based on tensile tests, static on MTS and dynamic on the first tensile loading in optimized tensile split Hopkinson bar (TSHB) tests at different strain rates for La sheet specimens, this study determined the J-C type tensile constitutive equation of La metal. It was found that the La sheet specimens were fractured during the first tensile loading in TSHB tests. The numerical simulations of transmitted and reflected pulses of TSHB tests for La sheet specimens using strain rate dependent failure strain criterion were consistent with the experimental data. The relation between dynamic failure strength and strain rates was discussed. From scanning electron microscope investigation of fractured La specimens, it was found that damage evolution patterns at high loading rates tend to become regular.

Constitutive Equation for 7050 Aluminum Alloy at High Temperatures

2006 ◽  
Vol 532-533 ◽  
pp. 125-128 ◽  
Author(s):  
Xiu Li Fu ◽  
Xing Ai ◽  
Song Zhang ◽  
Yi Wan
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Test System ◽  
Machining Process ◽  
Hopkinson Pressure Bar ◽  
Split Hopkinson ◽  
Pressure Bar

Accurately material constitutive model is essential to understand and predict machining process. High temperature split Hopkinson pressure bar (SHPB) test system is used to investigate flow stress behavior and characteristics of 7050-T7451 aluminum alloy. Specimens are tested from 200°C to 550°C at intervals of 50°C and room temperature, at strain-rate of 2800s-1. The experimental results show that flow stress is strongly dependent on temperature as well as strain rate, flow stress decreases with the increase of temperature, while increase with the increasing of strain rate. The material parameters are determined for both Johnson-Cook constitutive equation and modified Johnson-Cook constitutive equation. The modified JC equation is more suitable for expressing the dynamic behavior of 7050-T7451 aluminum alloy.

scholarly journals Study on the dynamic properties of AM-SLM AlSi10Mg alloy using the Split Hopkinson Pressure Bar (SHPB) technique

2018 ◽  
Vol 183 ◽  
pp. 04005 ◽  
Author(s):  
Bar Nurel ◽  
Moshe Nahmany ◽  
Adin Stern ◽  
Nahum Frage ◽  
Oren Sadot
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Static Mechanical ◽  
Split Hopkinson ◽  
Pressure Bar

Additive manufacturing by Selective Laser Melting of metals is attracting substantial attention, due to its advantages, such as short-time production of customized structures. This technique is useful for building complex components using a metallic pre-alloyed powder. One of the most used materials in AMSLM is AlSi10Mg powder. Additively manufactured AlSi10Mg may be used as a structural material and it static mechanical properties were widely investigated. Properties in the strain rates of 5×102–1.6×103 s-1 and at higher strain rates of 5×103 –105 s-1 have been also reported. The aim of this study is investigation of dynamic properties in the 7×102–8×103 s-1 strain rate range, using the split Hopkinson pressure bar technique. It was found that the dynamic properties at strain-rates of 1×103–3×103 s-1 depend on a build direction and affected by heat treatment. At higher and lower strain-rates the effect of build direction is limited. The anisotropic nature of the material was determined by the ellipticity of samples after the SHPB test. No strain rate sensitivity was observed.

Experimental Research of Foamed Ceramic Composite under Dynamic Loading Using SHPB

2013 ◽  
Vol 718-720 ◽  
pp. 112-116
Author(s):  
Xu Yang Li ◽  
Rui Yuan Huang ◽  
Yong Chi Li ◽  
Guang Fa Gao
Keyword(s):  
Ceramic Composite ◽  
Split Hopkinson Pressure Bar ◽  
Strain Rates ◽  
Test Results ◽  
Hopkinson Pressure Bar ◽  
Softening Effect ◽  
Stress Equilibrium ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Versus Strain

The Split Hopkinson Pressure Bar (SHPB) is used to investigate the dynamic compressive mechanical behavior of a new foamed ceramic composite under impact loading. The stress versus strain curves are obtained under high strain rates. The test results are considered to be able to assure conformability of the tests, validate the stress equilibrium assumption, and show that the stress versus strain curves of foamed ceramic composite display strain hardening effect and damage softening effect as brittle materials. Meanwhile the curve includes short plateau region while no densification region.

scholarly journals Blasting-Induced Permeability Enhancement of Ore Deposits Associated with Low-Permeability Weakly Weathered Granites Based on the Split Hopkinson Pressure Bar

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Lei Yan ◽  
Wenhua Yi ◽  
Liansheng Liu ◽  
Jiangchao Liu ◽  
Shenghui Zhang
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Deformation Modulus ◽  
Constant Speed ◽  
Initial Porosity ◽  
Peak Strain ◽  
Variable Speed ◽  
Hopkinson Pressure Bar ◽  
Impact Compression ◽  
Split Hopkinson ◽  
Pressure Bar

By utilizing the improved split Hopkinson pressure bar (SHPB) test device, uniaxial, constant-speed cyclic, and variable-speed cyclic impact compression tests were conducted on weakly weathered granite samples. By combining nuclear magnetic resonance (NMR) and triaxial seepage tests, this study investigated the change laws in the mechanical properties, porosity evolution, and permeability coefficients of the samples under cyclic impacts. The results showed that in constant-speed cyclic impacts with increasing impact times, deformation modulus decreased, whilst porosity firstly decreased and then increased. Furthermore, dynamic peak strength firstly increased and then decreased whereas peak strain constantly increased before failure of the samples. In the variable-speed cyclic impacts, as impact times increased, deformation modulus firstly increased and then declined with damage occurring after four impact times. The compaction process weakened and even disappeared with increasing initial porosity. Three types of pores were found in the samples that changed in multiscale under cyclic loading. In general, small pores extended to medium- and large-sized pores. After three variable-speed cyclic impacts, the porosity of the samples was larger than the initial porosity and the permeability coefficient was greater than its initial value. The results demonstrate that the purpose of enhancing permeability and keeping the ore body stable can be achieved by conducting three variable-speed cyclic impacts on the samples.

Can a three-dimensional composite really provide better mechanical performance compared to two-dimensional composite under compressive loading?

2018 ◽  
Vol 38 (2) ◽  
pp. 49-61 ◽  
Author(s):  
M Tarfaoui ◽  
M Nachtane
Keyword(s):  
Mechanical Performance ◽  
Split Hopkinson Pressure Bar ◽  
Compressive Loading ◽  
Three Dimensional ◽  
Woven Composites ◽  
Two Dimensional ◽  
Hopkinson Pressure Bar ◽  
Out Of Plane ◽  
Split Hopkinson ◽  
Pressure Bar

A series of split Hopkinson pressure bar tests on two-dimensional and three-dimensional woven composites were presented in order to obtain a reliable comparison between the two types of composites and the effect of the z-yarns along the third direction. These tests were done along different configurations: in-plane and out-of-plane compression test. For the three-dimensional woven composite, two different configurations were studied: compression responses along to the stitched direction and orthogonal to the stitched direction. It was found that three-dimensional woven composites exhibit an increase in strength for both: in-plane and out-of-plane tests.

Characterization and Constitutive Modeling of a Plasticized Poly(vinyl Chloride) for a Broad Range of Strain Rates

2001 ◽  
Vol 74 (4) ◽  
pp. 560-573 ◽  
Author(s):  
Yan Wang ◽  
Ellen M. Arruda ◽  
Phillip A. Przybylo
Keyword(s):  
Vinyl Chloride ◽  
Constitutive Modeling ◽  
Split Hopkinson Pressure Bar ◽  
Test System ◽  
Strain Rates ◽  
Impact Compression ◽  
Plasticized Pvc ◽  
Rate Dependent ◽  
Poly Vinyl Chloride ◽  
Compression Data

Abstract The mechanical behavior, morphological characterization and constitutive modeling of plasticized poly(vinyl chloride) (or PVC) are studied in this paper. The plasticized PVC is tested to large strains over a broad range of strain rates. Uniaxial and plane strain compression data at various constant strain rates ranging from −0.001 to −10 s−1 are collected on a conventional servohydraulic test system. Additional uniaxial impact compression data at approximately constant strain rates ranging from −1160 to −5560 s−1 are obtained using an aluminum split Hopkinson pressure bar apparatus. The large strain load/unload response of the plasticized PVC is nonlinear, it contains hysteresis and plastic deformation, and the initial response is highly rate dependent when the strain rate spans the transition zone between quasi-static and impact strain rates at room temperature. The morphology of plasticized PVC is analyzed via differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA), and described as a physically entangled network. A three-dimensional rate dependent constitutive model for plasticized PVC is developed and shown to successfully predict its stress—strain behavior over a broad range of strain rates.

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.

Sign in / Sign up

Export Citation Format

Share Document