scholarly journals Mechanical properties and constitutive model of Sn-58Bi alloy

2021 ◽  
Author(s):  
Kebin Zhang ◽  
Wenbin Li ◽  
Ping Song ◽  
Changfang Zhao ◽  
Kewin Zhang
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Constitutive Model ◽  
Strain Rate ◽  
Compressive Stress ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Strain Rates ◽  
Stress Strain ◽  
Static Conditions

Abstract Sn-58Bi alloy is a strain-rate-sensitive material. To study the mechanical properties of Sn-58Bi alloy, an MTS universal testing machine and split-Hopkinson pressure bar were used to conduct quasi-static and dynamic testing on Sn-58Bi alloy, obtaining the stress-strain curve of Sn-58Bi alloy at the strain rate of 0.001–6316 s−1. By comparing the tensile and compressive stress–strain curves of Sn-58Bi alloy under quasi-static conditions, it is found that Sn-58Bi alloy is brittle, with its tensile yield strength lower than its compressive yield strength. By comparing the compressive stress–strain curves of Sn-58Bi alloy at different strain rates, it is found that the yield strength of Sn-58Bi alloy increases with increasing strain rate, and a strain-hardening phenomenon is manifested at high strain rate. By revising the Johnson–Cook constitutive model, the constitutive model of Sn-58Bi alloy at different strain rates was established, with the calculated results of the model in good agreement with the experimental results.

scholarly journals Dynamic Constitutive Model of Ultra-High Molecular Weight Polyethylene (UHMWPE): Considering the Temperature and Strain Rate Effects

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1561 ◽  
Author(s):  
Kebin Zhang ◽  
Wenbin Li ◽  
Yu Zheng ◽  
Wenjin Yao ◽  
Changfang Zhao
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Plastic Material ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Ballistic Performance ◽  
Stress Strain ◽  
Different Temperatures

The temperature and strain rate significantly affect the ballistic performance of UHMWPE, but the deformation of UHMWPE under thermo-mechanical coupling has been rarely studied. To investigate the influences of the temperature and the strain rate on the mechanical properties of UHMWPE, a Split Hopkinson Pressure Bar (SHPB) apparatus was used to conduct uniaxial compression experiments on UHMWPE. The stress–strain curves of UHMWPE were obtained at temperatures of 20–100 °C and strain rates of 1300–4300 s−1. Based on the experimental results, the UHMWPE belongs to viscoelastic–plastic material, and a hardening effect occurs once UHMWPE enters the plastic zone. By comparing the stress–strain curves at different temperatures and strain rates, it was found that UHMWPE exhibits strain rate strengthening and temperature softening effects. By modifying the Sherwood–Frost model, a constitutive model was established to describe the dynamic mechanical properties of UHMWPE at different temperatures. The results calculated using the constitutive model were in good agreement with the experimental data. This study provides a reference for the design of UHMWPE as a ballistic-resistant material.

scholarly journals Determination of High Strain-Rate Compressive Stress-Strain Loops of Selected Polymers

2010 ◽  
Vol 24-25 ◽  
pp. 349-355 ◽  
Author(s):  
Takashi Yokoyama ◽  
Kenji Nakai
Keyword(s):  
Strain Rate ◽  
Compressive Stress ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Viscoelastic Behavior ◽  
Strain Range ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Stress Strain ◽  
Dissipation Energy

Compressive stress-strain loops of selected polymers at strain rates up to nearly 800/s are determined in a strain range of nearly 8% on the standard split Hopkinson pressure bar. Four different commercially available extruded polymers are tested at room temperature. The compressive stress-strain loops at low and intermediate strain rates are measured on an Instron testing machine. The effects of strain rate on the Young's modulus, flow stress and dissipation energy are discussed. It is shown that the area included within the stress-strain loop increases with increasing strain rate as well as a given strain, that is, all four extruded polymers tested exhibit intrinsic strain-rate dependent viscoelastic behavior and a high elastic aftereffect following complete unloading.

A Dynamic Mechanical Analysis of T2 Copper at High Strain Rates

2019 ◽  
Vol 812 ◽  
pp. 38-44
Author(s):  
Shuai Chen ◽  
Wen Bin Li ◽  
Xiao Ming Wang ◽  
Wen Jin Yao
Keyword(s):  
Yield Strength ◽  
Strain Rate ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Pure Copper ◽  
Dislocation Slip ◽  
Strain Rates ◽  
High Strain Rates ◽  
Stress Strain ◽  
Shpb Test

This work compares the pure copper (T2 copper)’s stress-strain relationship at different strain rates in the uni-axial tension test and Split Hopkinson Pressure Bar (SHPB) test. Small samples were utilized in the high strain rate SHPB test in which the accuracy was modified by numerical simulation. The experimental results showed that the T2 copper’s yield strength at high strain rates largely outweighed the quasi static yield strength. The flow stress in the stress-strain curves at different strain rates appeared to be divergent and increased with the increase in strain rates, showing great strain strengthening and strain rate hardening effects. Metallographic observation showed that the microstructure of T2 copper changed from equiaxed grains to twins and the interaction between the dislocation slip zone grain boundary and twins promoted the super plasticity distortion in T2 copper.

scholarly journals Study on Dynamic Mechanical Properties and Constitutive Model Construction of TC18 Titanium Alloy

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 44 ◽  
Author(s):  
Changming Zhang ◽  
Anle Mu ◽  
Yun Wang ◽  
Hui Zhang
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Flow Stress ◽  
Yield Strength ◽  
Constitutive Model ◽  
Testing Machine ◽  
Dynamic Mechanical Properties ◽  
Stress Strain ◽  
Dynamic Mechanical ◽  
Different Temperatures

In order to investigate the static and dynamic mechanical properties of TC18 titanium alloy, the quasi-static stress–strain curve of TC18 titanium alloy under room temperature was obtained by DNS 100 electronic universal testing machine (Changchun Institute of Mechanical Science Co., Ltd., Changchun, China). Meanwhile, the flow stress–strain curves under different temperatures and strain rates are analyzed by split Hopkinson pressure bar (SHPB) device with synchronous assembly system. On the basis of the two experimental data, the JC constitutive model under the combined action of high temperature and impact load is established using the linear least squares method. The results show the following: the yield strength and flow stress of TC18 titanium alloy increase slowly with the increase of the strain rate, and the strain value corresponding to the yield strength is reduced. With the increase of strain, the flow stress increases at first and then decreases at different temperatures. The strain value corresponding to the transition point rises with the temperature increase, and the corresponding stress value remains basically unchanged. With the increase of experimental temperature, the flow stress shows a downward trend, and the JC constitutive model can predict the plastic flow stress well.

Measurement of Mechanical Properties of St 37 Material at High Strain Rates Using a Split Hopkinson Pressure Bar

2014 ◽  
Vol 660 ◽  
pp. 562-566 ◽  
Author(s):  
Akbar Afdhal ◽  
Leonardo Gunawan ◽  
Sigit P. Santosa ◽  
Ichsan Setya Putra ◽  
Hoon Huh
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Test Specimen ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Stress Strain ◽  
Split Hopkinson ◽  
Pressure Bar

The dynamic mechanical properties of a material are important keys to investigate the impact characteristic of a structure such as a crash box. For some materials, the stress-strain relationships at high strain rate loadings are different than that at the static condition. These mechanical properties depend on the strain rate of the loadings, and hence an appropriate testing technique is required to measure them. To measure the mechanical properties of a material at high strain rates, ranging from 500 s-1 to 10000 s-1, a Split Hopkinson Pressure Bar is commonly used. In the measurements, strain pulses are generated in the bars system, and pulses being reflected and transmitted by a test specimen in the bar system are measured. The stress-strain curves as the material properties of the test specimen are obtained by processing the measured reflected and transmitted pulses. This paper presents the measurements of the mechanical properties of St 37 mild steel at several strain rates using a Split Hopkinson Pressure Bar. The stress-strain curves obtained in the measurement were curve fitted using the Power Law. The results show that the strength of St 37 material increases as the strain rate increases.

scholarly journals Rheological Behaviours and Constitutive Models for 9Cr18Mo Stainless Steel at High Temperature and High Strain Rate

2021 ◽  
Author(s):  
Haishen Jia ◽  
Jilin Zhang ◽  
Xiangbin Yi ◽  
Jiancheng Shen ◽  
Linhu Tang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Constitutive Model ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Constitutive Models ◽  
Stress Strain

Abstract The compression test was conducted on 9Cr18Mo stainless steel by using the UTM5305 universal testing machine and the split Hopkinson pressure bar (SHPB) test device. In this way, the stress–strain curves pertaining to quasi-static (strain rate of 0.001 ~ 0.1 s-1) and dynamic (temperature range of 25 ~ 650 ℃ and strain rate of 800 ~ 4,000 s-1) states were attained. According to the stress–strain curves, the rheological behaviours of 9Cr18Mo stainless steel at high temperature and high strain rate were discussed. Based on the test data, the parameters of two constitutive models (Johnson-Cook (J-C) and Power-Law (P-L)) for 9Cr18Mo stainless steel were identified and the correlation coefficients (R) and average absolute relative errors (AAREs) of the two constitutive models were compared. The results showed that 9Cr18Mo stainless steel presents strain-rate sensitivity and significant thermal softening, that is, the flow stress on 9Cr18Mo stainless steel increases with strain rate while significantly reduces with increasing temperature. The R values are 0.9697 and 0.9896 and the AAREs of two constitutive models are 2.77% and 1.85%, respectively. Hence, the P-L constitutive model shows a higher prediction accuracy compared with the J-C constitutive model and can better describe the rheological behaviours of 9Cr18Mo stainless steel at high temperature and high strain rate.

Tensile Stress-Strain Curves Modeling of Four Kinds of Solders with Temperature and Rate Dependence

2005 ◽  
Vol 297-300 ◽  
pp. 905-911 ◽  
Author(s):  
Xu Chen ◽  
Li Zhang ◽  
Masao Sakane ◽  
Haruo Nose
Keyword(s):  
Tensile Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Strain Rate Range ◽  
Rate Dependence ◽  
Strain Rates ◽  
Stress Strain ◽  
Rate Range

A series of tensile tests at constant strain rate were conducted on tin-lead based solders with different Sn content under wide ranges of temperatures and strain rates. It was shown that the stress-strain relationships had strong temperature- and strain rate- dependence. The parameters of Anand model for four solders were determined. The four solders were 60Sn-40Pb, 40Sn-60Pb, 10Sn-90Pb and 5Sn-95Pb. Anand constitutive model was employed to simulate the stress-strain behaviors of the solders for the temperature range from 313K to 398K and the strain rate range from 0.001%sP -1 P to 2%sP -1 P. The results showed that Anand model can adequately predict the rate- and temperature- related constitutive behaviors at all test temperatures and strain rates.

Plastic Flow Stress and Constitutive Model for H96 Brass Alloy

2015 ◽  
Vol 782 ◽  
pp. 130-136 ◽  
Author(s):  
Ping Zhou ◽  
Wei Guo Guo ◽  
Hai Hui Wu
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Plastic Flow ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Experimental Results ◽  
Dynamic Strain ◽  
Strain Rates ◽  
Brass Alloy ◽  
Plastic Flow Stress

To explore the thermo-mechanical response of H96 brass alloy, the quasi-static (universal-testing machine) and dynamic (the split Hopkinson pressure bar apparatus) uniaxial compression experiments have been performed under the temperatures from 293 K to 873 K and the strain rates from 0.001 s-1 to 6000 s-1, and the strains over 60% are obtained. Results show that, H96 brass alloy has strong strain hardening behavior, and it becomes weaker with the increasing temperature. In addition, this alloy is sensitive to strain rates; and, it has temperature sensitivity, the dynamic strain aging occurs at the temperature of 473 K and a quasi-static strain rate of 0.001 s-1. Based on the thermal activation dislocation mechanism, paralleled with the experimental results, a plastic flow constitutive model with the physical conception is developed. The model is suitable to predict the plastic flow stress at different temperatures and strain rates. According to comparing results, the model predictions are in good agreement with the experimental results.

High Strain-Rate Compressive Behavior and Constitutive Modeling of Selected Polymers Using Modified Ramberg-Osgood Equation

2014 ◽  
Vol 566 ◽  
pp. 80-85
Author(s):  
Kenji Nakai ◽  
Takashi Yokoyama
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Compressive Stress ◽  
Constitutive Modeling ◽  
High Strain ◽  
Strain Rates ◽  
Stress Strain ◽  
Strain Behavior ◽  
Least Squares Fit ◽  
Wide Range

The present paper is concerned with constitutive modeling of the compressive stress-strain behavior of selected polymers at strain rates from 10-3 to 103/s using a modified Ramberg-Osgood equation. High strain-rate compressive stress-strain curves up to strains of nearly 0.08 for four different commercially available extruded polymers were determined on the standard split Hopkinson pressure bar (SHPB). The low and intermediate strain-rate compressive stress-strain relations were measured in an Instron testing machine. Six parameters in the modified Ramberg-Osgood equation were determined by fitting to the experimental stress-strain data using a least-squares fit. It was shown that the monotonic compressive stress-strain behavior over a wide range of strain rates can successfully be described by the modified Ramberg-Osgood constitutive model. The limitations of the model were discussed.

Strain-Rate Dependence of Compressive Yield Strength of Titanium Grade 4 with Coarse-Grained and Ultrafine-Grained Structures: Experimental Results and Theoretical Calculation

2018 ◽  
Vol 1145 ◽  
pp. 100-105
Author(s):  
Ivan V. Smirnov ◽  
Alexander Y. Konstantinov
Keyword(s):  
Yield Strength ◽  
Strain Rate ◽  
Yield Stress ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Pure Titanium ◽  
Coarse Grained ◽  
Strain Rates ◽  
Ultrafine Grained ◽  
Titanium Grade

The nanocrystalline (NC) and ultrafine-grained (UFG) structures of metallic materials can lead to their extraordinary high strength. However, most of the papers on this topic consider deformation parameters of NC and UFG materials only for the case of quasi-static tensile tests. Characteristics of dynamic strength and fracture of such materials remain unexplored. This paper presents a study of the mechanical behavior of pure titanium Grade 4 with a coarse-grained (CG) and UFG structure under uniaxial compression with different strain rates. The UFG structure was provided using the method of equal-channel angular pressing. The dynamic compression was carried out on a setup with the Split-Hopkinson pressure bar. It is found that in the observed range of strain rates 10–3-3×103 s–1, the yield stress of the CG titanium increases by 20%, and does not exceed the yield stress of the UFG titanium. However, the yield stress of the UFG titanium remains close to a quasi-static value. It is shown that these strain-rate dependencies of the yield strength can be predicted by the incubation time approach. The calculated curves show that at strain rates above 104 s–1 the yield stress of the CG titanium becomes higher than the yield strength of the UFG titanium.

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