scholarly journals Ultra-High Strain Rate Constitutive Modeling of Pure Titanium Using Particle Impact Test

2020 ◽  
Vol 87 (9) ◽  
Author(s):  
Xuchen Wang ◽  
Mostafa Hassani
Keyword(s):  
Strain Rate ◽  
Constitutive Modeling ◽  
Impact Test ◽  
High Strain ◽  
Pure Titanium ◽  
Particle Impact ◽  
Strain Rates ◽  
Commercially Pure Titanium ◽  
High Strain Rates ◽  
High Deformation

Abstract With the advent of advanced testing techniques such as laser-induced particle impact test, it is possible to study materials mechanics under extremely high deformation rates, i.e., above 106 s−1, a relatively less explored regime of strain rates. Inspired by the classical Taylor impact test, in this study, we accelerate microparticles of commercially pure titanium to a range of impact velocities, from 144 to 428 m/s, toward a rigid substrate and record their deformation upon impact in real-time. We also conduct finite element modeling of the experimentally recorded impacts using two constitutive equations, namely, Johnson–Cook and Zerilli–Armstrong. We show that the titanium microparticles experience strain rates in the range of 106–1010 s−1 upon impact. We evaluate the capability of the Johnson–Cook and Zerilli–Armstrong equations in predicting the deformation response of pure Ti at ultra-high strain rates. With an optimization-based constitutive modeling approach, we also propose updated strain rate-related parameters for both equations and improve the extent to which the two models can describe the deformation of pure titanium at ultra-high strain rates.

scholarly journals Synchronized Full-Field Strain and Temperature Measurements of Commercially Pure Titanium under Tension at Elevated Temperatures and High Strain Rates

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
Guilherme Corrêa Soares ◽  
Mikko Hokka
Keyword(s):  
Elevated Temperatures ◽  
High Strain ◽  
Pure Titanium ◽  
Heating System ◽  
Strain Rates ◽  
Commercially Pure Titanium ◽  
High Strain Rates ◽  
Noise Floor ◽  
Full Field ◽  
Commercially Pure

Understanding the mechanical behavior of materials at extreme conditions, such as high temperatures, high strain rates, and very large strains, is fundamental for applications where these conditions are possible. Although tensile testing has been used to investigate material behavior under high strain rates and elevated temperatures, it disregards the occurrence of localized strains and increasing temperatures during deformation. The objective of this work is to combine synchronized full-field techniques and an electrical resistive heating system to investigate the thermomechanical behavior of commercially pure titanium under tensile loading at high temperatures and high strain rates. An electrical resistive heating system was used to heat dog-bone samples up to 1120 °C, which were then tested with a tensile Split Hopkinson Pressure Bar at strain rates up to 1600 s−1. These tests were monitored by two high-speed optical cameras and an infrared camera to acquire synchronized full-field strain and temperature data. The displacement and strain noise floor, and the stereo reconstruction error increased with temperature, while the temperature noise floor decreased at elevated temperatures. A substantial decrease in mechanical strength and an increase in ductility were observed with an increase in testing temperature. The localized strains during necking were much higher at elevated temperatures, while adiabatic heating was much lower or non-existent at elevated temperatures.

scholarly journals Deformation Resistance and Recrystallization of Commercially Pure Titanium in the High Strain Rate Hot Deformation

1986 ◽  
Vol 72 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Takehide SENUMA ◽  
Hiroshi YADA ◽  
Hirobumi YOSHIMURA ◽  
Hisaaki HARADA ◽  
Takuji SHINDO ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Hot Deformation ◽  
High Strain ◽  
Pure Titanium ◽  
Deformation Resistance ◽  
Commercially Pure Titanium ◽  
Commercially Pure

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.

Tensile behaviors of co-woven-knitted fabric reinforced composites under various strain rates

2011 ◽  
Vol 45 (24) ◽  
pp. 2495-2506 ◽  
Author(s):  
Pibo Ma ◽  
Hong Hu ◽  
Lvtao Zhu ◽  
Baozhong Sun ◽  
Bohong Gu
Keyword(s):  
Strain Rate ◽  
Failure Modes ◽  
Shear Failure ◽  
High Strain ◽  
Tensile Failure ◽  
Knitted Fabric ◽  
Strain Rates ◽  
High Strain Rates ◽  
Textile Composite ◽  
Interface Failure

This article reports the tensile behaviors of a novel kind of 3D textile composite, named as co-woven-knitted fabric (CWKF) reinforced composite, under quasi-static and high strain rates. The tensile tests were conducted along the warp direction (0°), bias direction (45°), and weft direction (90°) at quasi-static strain rate of 0.001/s and high strain rates ranging from 1589/s to 2586/s. The results indicate that the tensile strength, failure strain, tensile stiffness, energy absorption, and resilient energy are strain rate sensitive along all the three directions. The relationships between the mechanical parameters and the strain rate were also analyzed. The fractograph of the CWKF composite demonstrate that the tensile failure modes are matrix shear failure and fibers breakage under the quasi-static testing condition while interface failure and fibers pullout are at high strain rates.

PRESSURE-SENSITIVITY AND CONSTITUTIVE MODELING OF AN ELASTOMER AT HIGH STRAIN RATES

2009 ◽  
Author(s):  
T. Jiao ◽  
R. J. Clifton ◽  
S. E. Grunschel ◽  
Mark Elert ◽  
Michael D. Furnish ◽  
...  
Keyword(s):  
Constitutive Modeling ◽  
High Strain ◽  
Strain Rates ◽  
Pressure Sensitivity ◽  
High Strain Rates

Comparative Study of the Dynamic Behavior of AA2519 Aluminum Alloy in T6 and T8 Temper Conditions

2019 ◽  
Author(s):  
Adewale Olasumboye ◽  
Gbadebo Owolabi ◽  
Olufemi Koya ◽  
Horace Whitworth ◽  
Nadir Yilmaz
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Stress Response ◽  
Flow Stress ◽  
Yield Strength ◽  
Strain Rate ◽  
High Strain ◽  
Second Phase ◽  
Strain Rates ◽  
High Strain Rates

Abstract This study investigates the dynamic response of AA2519 aluminum alloy in T6 temper condition during plastic deformation at high strain rates. The aim was to determine how the T6 temper condition affects the flow stress response, strength properties and microstructural morphologies of the alloy when impacted under compression at high strain rates. The specimens (with aspect ratio, L/D = 0.8) of the as-cast alloy used were received in the T8 temper condition and further heat-treated to the T6 temper condition based on the standard ASTM temper designation procedures. Split-Hopkinson pressure bar experiment was used to generate true stress-strain data for the alloy in the range of 1000–3500 /s strain rates while high-speed cameras were used to monitor the test compliance with strain-rate constancy measures. The microstructures of the as received and deformed specimens were assessed and compared for possible disparities in their initial microstructures and post-deformation changes, respectively, using optical microscopy. Results showed no clear evidence of strain-rate dependency in the dynamic yield strength behavior of T6-temper designated alloy while exhibiting a negative trend in its flow stress response. On the contrary, AA2519-T8 showed marginal but positive response in both yield strength and flow behavior for the range of strain rates tested. Post-deformation photomicrographs show clear disparities in the alloys’ initial microstructures in terms of the second-phase particle size differences, population density and, distribution; and in the morphological changes which occurred in the microstructures of the different materials during large plastic deformation. AA2519-T6 showed a higher susceptibility to adiabatic shear localization than AA2519-T8, with deformed and bifurcating transformed band occurring at 3000 /s followed by failure at 3500 /s.

scholarly journals An Image-Based Impact Test for the High Strain Rate Tensile Properties of Brittle Materials

2018 ◽  
Vol 183 ◽  
pp. 02042
Author(s):  
Lloyd Fletcher ◽  
Fabrice Pierron
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
High Strain Rate ◽  
Strain Rate ◽  
Stress Wave ◽  
High Strain ◽  
Brittle Materials ◽  
Test Method ◽  
Strain Rates ◽  
High Strain Rates

Testing ceramics at high strain rates presents many experimental diffsiculties due to the brittle nature of the material being tested. When using a split Hopkinson pressure bar (SHPB) for high strain rate testing, adequate time is required for stress wave effects to dampen out. For brittle materials, with small strains to failure, it is difficult to satisfy this constraint. Because of this limitation, there are minimal data (if any) available on the stiffness and tensile strength of ceramics at high strain rates. Recently, a new image-based inertial impact (IBII) test method has shown promise for analysing the high strain rate behaviour of brittle materials. This test method uses a reflected compressive stress wave to generate tensile stress and failure in an impacted specimen. Throughout the propagation of the stress wave, full-field displacement measurements are taken, from which strain and acceleration fields are derived. The acceleration fields are then used to reconstruct stress information and identify the material properties. The aim of this study is to apply the IBII test methodology to analyse the stiffness and strength of ceramics at high strain rates. The results show that it is possible to identify the elastic modulus and tensile strength of tungsten carbide at strain rates on the order of 1000 s-1. For a tungsten carbide with 13% cobalt binder the elastic modulus was identified as 516 GPa and the strength was 1400 MPa. Future applications concern boron carbide and sapphire, for which limited data exist in high rate tension.

Compressive Behavior of Plain and Fiber-Reinforced High-Strength Concrete Subjected to High Strain Rate Loading

2011 ◽  
Vol 82 ◽  
pp. 57-62 ◽  
Author(s):  
Sha Sha Wang ◽  
Min Hong Zhang ◽  
Ser Tong Quek
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strength Concrete ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
High Strength ◽  
Strain Rates ◽  
Compressive Behavior ◽  
High Strain Rates ◽  
Strength Concrete

This paper presents a laboratory experimental study on the effect of high strain rate on compressive behavior of plain and fiber-reinforce high-strength concrete (FRHSC) with similar strength of 80-90 MPa. Steel fibers, polyethylene fibers, and a combination of these were used in the FRHSC. A split Hopkinson pressure bar equipment was used to determine the concrete behavior at strain rates from about 30 to 300 s-1. The ratio of the strength at high strain rates to that at static loading condition, namely dynamic increase factor (DIF), of the concretes was determined and compared with that recommended by CEB-FIP code. Fracture patterns of the specimens at high strain rates are described and discussed as well. Results indicate that the CEB-FIP equation is applicable to the plain high strength concrete, but overestimates the DIF of the FRHSC at strain rates beyond a transition strain rate of 30 s-1. Based on the experimental results, a modified equation on DIF is proposed for the FRHSC.

Sign in / Sign up

Export Citation Format

Share Document