Superplasticity and Superplastic Tensile Behaviour of AA5083

2014 ◽  
Vol 902 ◽  
pp. 24-28 ◽  
Author(s):  
B. Yogesha ◽  
H.V. Divya ◽  
S.S. Bhattacharya
Keyword(s):  
Superplastic Deformation ◽  
Polycrystalline Materials ◽  
Uniaxial Tensile ◽  
Tensile Behaviour ◽  
Uniaxial Tensile Test ◽  
Strain Rates ◽  
Analytical Characterization ◽  
Structural Superplasticity ◽  
Aa5083 Alloy

In the present investigation experimental and analytical characterization of the high temperature (superplastic) deformation of AA5083 alloy was carried out. Uniaxial tensile test was performed in a temperature range of 748 823K at different initial strain rates. Superplasticity is the ability of polycrystalline materials to exhibit, in a relatively uniform/isotropic manner, very large tensile elongations prior to failure, under appropriate conditions of temperature and strain rates. The phenomenon of superplasticity arising due to specific microstructural conditions is commonly referred to as "structural" superplasticity or "micrograin" superplasticity.

Modeling of Anisotropic Deformation in Superplastic Sheet Metal Stretching

2005 ◽  
Vol 127 (1) ◽  
pp. 159-164 ◽  
Author(s):  
Fadi K. Abu-Farha ◽  
Marwan K. Khraisheh
Keyword(s):  
Sheet Metal ◽  
Microstructural Evolution ◽  
Superplastic Deformation ◽  
Yield Function ◽  
Internal Variables ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Initial State ◽  
Plane Stress Condition ◽  
Deformation And Failure

Currently available models describing superplastic deformation are mostly based on uniaxial tensile test data and assume isotropic behavior, thus leading to limited predictive capabilities of material deformation and failure. In this work we present a multi-axial microstructure-based constitutive model that describes the anisotropic superplastic deformation within the continuum theory of viscoplasticity with internal variables. The model accounts for microstructural evolution and employs a generalized anisotropic dynamic yield function. The anisotropic yield function can describe the evolution of the initial state of anisotropy through the evolution of unit vectors defining the direction of anisotropy during deformation. The generalized model is then reduced to the plane stress condition to simulate sheet metal stretching in superplastic blow forming using pressurized gas. Different ratios of biaxial stretching were investigated, including the case simulating the uniaxial loading condition, where the model successfully captured the uniaxial experimental data. The model is also used to develop a new forming pressure profile that accounts for anisotropy and microstructural evolution.

Superplastic Behaviors of Casting AZ31 Magnesium Alloy

2007 ◽  
Vol 551-552 ◽  
pp. 237-240
Author(s):  
Hong Bo Li ◽  
J. Zhao ◽  
Jun Ting Luo ◽  
M. Hang
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Deformation Behavior ◽  
Superplastic Deformation ◽  
Optical Microscope ◽  
Az31 Magnesium Alloy ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Tensile Experiment ◽  
Uniaxial Tensile Experiment

The superplasticity of magnesium alloy is important in industrial application. However the superplastic deformation of casting magnesium alloy is hard to be realized. In this paper, the stress–strain behaviors of casting AZ31 magnesium alloy with various strain rates at different deformation temperatures were investigated. The alloy was tested in the tensile condition with initial grain size of 25μm. It was found that the elongation of the alloy at 400°C with ε& = 4.25×10-4 s-1 is almost 200%. According to the results of uniaxial tensile experiment, the alloy exhibited superplastic deformation behavior with the slow stain rate in a temperature range of 350 to 450°C. The microstructures deformed and undeformed samples were observed with aid of optical microscope.

Tensile behaviour and damage characteristic of recycled aluminium alloys AA6061 undergoing finite strain deformation

2020 ◽  
pp. 095440622095034
Author(s):  
CS Ho ◽  
MK Mohd Nor
Keyword(s):  
Strain Rate ◽  
Aluminium Alloys ◽  
Elevated Temperatures ◽  
Microstructural Analysis ◽  
Optical Microscope ◽  
Uniaxial Tensile ◽  
Tensile Behaviour ◽  
Uniaxial Tensile Test ◽  
Increasing Temperature ◽  
Damage Characteristic

The effects of temperature and strain rate of hot-forged recycled aluminium alloys AA6061 are examined via uniaxial tensile test implementations in this paper. The tests are conducted at elevated temperatures of 100 °C, 200 °C and 300 °C, at two different strain rates of 10−4 s−1 and 10−3 s−1. The tensile behaviour and damage characteristic are analysed in terms of stress-strain curves and microstructural analysis, respectively. The microstructure and fracture surface of such materials are observed using Scanning Electron Microscope (SEM) and Optical Microscope (OM). The flow stress of recycled AA6061 increases with increasing strain rate and decreases with increasing temperature. ImageJ software is used to quantify void characteristics. It is observed that the quantity and size of the micro-voids are strain-rate sensitive. This is due to the growth and coalescence of the micro-voids. The OM analysis shows the gap between the grain boundaries becomes wider with the increasing temperature that affects the strength of the material. The outcome of this work gives valuable information before the appropriate applications, especially in automotive and aerospace fields, can be established. It can be agreed that there is still a need for improved recycling methods to fulfil the needs in the required applications, as shown by its primary resources. It is a massive challenge and an obvious drawback in such materials due to the degradation of material’s properties related to damage.

Effect of quasi-static and intermediate strain rates on the tensile properties of hybrid polymer composites

2021 ◽  
pp. 095440622110288
Author(s):  
Fatih Balikoglu ◽  
Tayfur K Demircioglu ◽  
Ege A Diler ◽  
Akın Ataş
Keyword(s):  
Tensile Strength ◽  
Strain Rate ◽  
Polymer Composites ◽  
Hybrid Composites ◽  
Uniaxial Tensile ◽  
Tensile Behaviour ◽  
Strain Rates ◽  
Hybrid Polymer ◽  
Hybrid Laminates ◽  
Intermediate Strain Rates

This study presents the results of an investigation on the tensile behaviour of hybrid polymer composites under different strain rates. Glass/carbon, aramid/carbon, glass/aramid, and glass/aramid/carbon hybrid laminates were produced using vacuum assisted resin transfer molding method with epoxy resin system. Uniaxial tensile testing was performed to determine the tensile strength, modulus and failure strain of the hybrid laminates under quasi static (0.001 s‒1) and intermediate (5 and 10 s‒1) strain rates. Tensile strength and elastic modulus of hybrid composites increased with increasing the strain rate. Hybrid laminates with glass fibre were more sensitive to the strain rate. Carbon layers located at the centre of the hybrid laminates resulted in increased tensile strength, indicating the major role of stacking sequence on the behaviour of hybrid composites. Scanning electron microscope (SEM) was used to examine the fracture surfaces of the laminates. The extent of damage propagation was significantly broader at intermediate strain rates.

scholarly journals Quantifying Tensile Properties of Bamboo Silicone Biocomposite using Yeoh Model

2018 ◽  
Vol 7 (4.26) ◽  
pp. 245 ◽  
Author(s):  
Kamarul Nizam Hassan ◽  
Jamaluddin Mahmud ◽  
Anwar P.P. Abdul Majeed ◽  
Mohd Azman Yahya
Keyword(s):  
Experimental Data ◽  
Tensile Properties ◽  
Coefficient Of Determination ◽  
Elastic Behaviour ◽  
Uniaxial Tensile ◽  
Tensile Behaviour ◽  
Uniaxial Tensile Test ◽  
Constitutive Function ◽  
Yeoh Model ◽  
Fitting Model

The utilisation of bamboo has the potential of improving the properties of silicone. However, a thorough investigation has yet to be reported on the mechanical properties of bamboo silicone biocomposite. This study was carried out with the aim to quantify the tensile properties and assess the tensile behaviour of bamboo silicone biocomposite using Yeoh hyperelastic constitutive function. The specimens were prepared from the mix of bamboo particulate and pure silicone at various fibre composition ratio (0wt%, 1wt%, 3wt% and 5wt%) cured overnight at room temperature. A uniaxial tensile test was carried out by adopting the ASTM D412 testing standard. The Coefficient of Variation, CV, and the Coefficient of Determination, r2, were determined to assess the reliability of the experimental data and fitting model. The results of the determined Yeoh material constants for 5wt% specimen is found to be C1 = 12.0603×10-3 MPa, C2 = 8.7353×10-5 MPa and C3 = -11.6165×10-8 MPa, compared to pure silicone (0wt%) C1 = 5.6087×10-3 MPa, C2 = 8.6639×10-5 MPa and C3 = -7.6510×10-8 MPa. The results indicate that the bamboo fibre improves the stiffness of the silicone rubber by 115 percent. A low variance was exhibited by the experimental data with a CV value of less than 8 percent. The Yeoh Model demonstrated an excellent prediction of the elastic behaviour of bamboo silicone biocomposite with a fitting accuracy of more than 99.93 percent.  

scholarly journals Hyperelastic and Viscoelastic Properties of Brain Tissue in Tension

2012 ◽  
Author(s):  
Badar Rashid ◽  
Michel Destrade ◽  
Michael D. Gilchrist
Keyword(s):  
Finite Element ◽  
Brain Tissue ◽  
Brain Injuries ◽  
Diffuse Axonal Injury ◽  
Viscoelastic Behavior ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Average Rise

Mechanical characterization of brain tissue at high loading velocities is particularly important for modelling Traumatic Brain Injury (TBI). During severe impact conditions, brain tissue experiences a mixture of compression, tension and shear. Diffuse axonal injury (DAI) occurs in animals and humans when the strains and strain rates exceed 10% and 10/s, respectively. Knowing the mechanical properties of brain tissue at these strains and strain rates is thus of particular importance, as they can be used in finite element simulations to predict the occurrence of brain injuries under different impact conditions. In this research, uniaxial tensile tests at strain rates of 30, 60 and 90/s up to 30% strain and stress relaxation tests in tension at various strain magnitudes (10%–60%) with an average rise time of 24 ms were performed. The brain tissue showed a stiffer response with increasing strain rates, showing that hyperelastic models are not adequate and that viscoelastic models are required. Specifically, the tensile engineering stress at 30% strain was 3.1 ± 0.49 kPa, 4.3 ± 0.86 kPa, 6.5 ± 0.76 kPa (mean ± SD) at strain rates of 30, 60 and 90/s, respectively. The Prony parameters were estimated from the relaxation data. Numerical simulations were performed using a one-term Ogden model to analyze hyperelastic and viscoelastic behavior of brain tissue up to 30% strain. The material parameters obtained in this study will help to develop biofidelic human brain finite element models, which subsequently can be used to predict brain injuries under impact conditions.

MEASUREMENT OF THE LOCAL LONGITUDINAL STRAIN IN THE UNIAXIAL TENSILE TEST UP TO HIGH STRAIN RATES

1988 ◽  
Vol 49 (C3) ◽  
pp. C3-739-C3-743
Author(s):  
N. EISENREICH ◽  
C. FABRY ◽  
R. FISCHER ◽  
A. GEISSLER ◽  
H. P. KUGLER ◽  
...  
Keyword(s):  
Tensile Test ◽  
Longitudinal Strain ◽  
High Strain ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Strain Rates ◽  
High Strain Rates
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