Tensile behaviour of adhesive anchors under different strain rates

2019 ◽  
Vol 192 ◽  
pp. 113-125 ◽  
Author(s):  
Lenda T. Ahmed ◽  
Abass Braimah
2011 ◽  
Vol 82 ◽  
pp. 124-129 ◽  
Author(s):  
Ezio Cadoni ◽  
Matteo Dotta ◽  
Daniele Forni ◽  
Stefano Bianchi

In this paper the first results of the mechanical characterization in tension of two high strength alloys in a wide range of strain rates are presented. Different experimental techniques were used for different strain rates: a universal machine, a Hydro-Pneumatic Machine and a JRC-Split Hopkinson Tensile Bar. The experimental research was developed in the DynaMat laboratory of the University of Applied Sciences of Southern Switzerland. An increase of the stress at a given strain increasing the strain-rate from 10-3 to 103 s-1, a moderate strain-rate sensitivity of the uniform and fracture strain, a poor reduction of the cross-sectional area at fracture with increasing the strain-rate were shown. Based on these experimental results the parameters required by the Johnson-Cook constitutive law were determined.


Author(s):  
C. Ganesan ◽  
P.S. Joanna ◽  
Dalbir Singh

This study investigates about the effect of different strain rates on the tensile behaviour of kevlar epoxy composites and progressive failure of kevlar epoxy composites under displacement controlled axial loading. A series of experimental tests were conducted under different strain rates to find out the tensile behaviour of kevlar epoxy composites. Two different strain rates 0.5mm/ min and 1.5mm/ min were applied to the kevlar epoxy specimen in order to understand the difference in mechanical properties and progressive failures of composites. Tensile strength increases with an increase in strain rates. Failure in kevlar epoxy composites is analysed under different stages for both 0.5mm/min and 1.5 mm/min. For all the tests, failure starts with matrix cracking followed by delamination and ends with fracture.


2016 ◽  
Vol 68 (3) ◽  
pp. 127-140 ◽  
Author(s):  
Wei-ping Zhang ◽  
Hui Chen ◽  
Xiang-lin Gu

2019 ◽  
Vol 218 ◽  
pp. 667-680 ◽  
Author(s):  
Ezio Cadoni ◽  
Daniele Forni ◽  
Emmanuel Bonnet ◽  
Svatopluk Dobrusky

2014 ◽  
Vol 902 ◽  
pp. 24-28 ◽  
Author(s):  
B. Yogesha ◽  
H.V. Divya ◽  
S.S. Bhattacharya

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.


2011 ◽  
Vol 488-489 ◽  
pp. 286-289
Author(s):  
V.G. Izzard ◽  
C.H. Bradsell ◽  
H. Hadavinia ◽  
V.J. Morris ◽  
P.J.S. Foot ◽  
...  

One of the primary applications of polymer based cellular solids is to act as an energy absorbing material during impact where compressive strain rates may reach 500-800/s. In reality, impacts occur over a wide range of temperatures and velocities at different angles of incidence. Understanding and modelling the behaviour of the polymer foams requires characterisation of the material response in detail. The stress-strain response that covers both compressive and tensile behaviour for a wide range of strain rates and temperatures are needed to characterize the mechanical performance of polymer foams as polymeric foams are highly nonlinear materials that undergo large deformation in crashworthiness related cases. It is reported in literature that any increase or decrease in temperature over the glass transition region can cause changes by order of magnitude in elastic modulus of polymeric foams. However, creation of cross linking at high temperature can affect the elastic modulus. In this work, the behaviour of two, polyamide-6 (PA-6) based closed cell foams at elevated temperatures were investigated covering the glass transition temperature. This work presents the variation of elastic and tangent modulus of two low densities PA-6 and PA-6/polyolefin (Nylon alloy) based foams. Empirical equations have been proposed to allow the prediction of modulus over a temperature range of 23°C to 120°C for these materials.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1653
Author(s):  
Muhammad Ameerul Atrash Mohsin ◽  
Lorenzo Iannucci ◽  
Emile S. Greenhalgh

A dynamic tensile experiment was performed on a rectangular specimen of a non-crimp fabric (NCF) thermoplastic composite T700 carbon/polyamide 6.6 specimens using a split Hopkinson pressure (Kolsky) bar (SHPB). The experiment successfully provided useful information on the strain-rate sensitivity of the NCF carbon/thermoplastic material system. The average tensile strength at three varying strain rates: 700, 1400, and 2100/s was calculated and compared to the tensile strength measured from a standardized (quasi-static) procedure. The increase in tensile strength was found to be 3.5, 24.2, and 45.1% at 700, 1400, and 2100/s strain rate, respectively. The experimental findings were used as input parameters for the numerical model developed using a commercial finite element (FE) explicit solver LS-DYNA®. The dynamic FE model was validated against experimental gathering and used to predict the composite system’s behavior in various engineering applications under high strain-rate loading conditions. The SHPB tension test detailed in this study provided the enhanced understanding of the T700/polyamide 6.6 composite material’s behavior under different strain rates and allowed for the prediction of the material’s behavior under real-world, dynamic loading conditions, such as low-velocity and high-velocity impact.


2014 ◽  
Vol 611-612 ◽  
pp. 92-98 ◽  
Author(s):  
Irena Eipert ◽  
Giribaskar Sivaswamy ◽  
Rahul Bhattacharya ◽  
Muhammad Amir ◽  
Paul Blackwell

Present work focusses on the effect of stress relaxation on the tensile behaviour of two commercially pure titanium alloys of different strength levels (Grade 1 and Grade 4) subjected to tensile tests at room temperature. The stress relaxation tests were performed by interrupting the tensile tests at regular strain intervals of 5% in the plastic region of the tensile curve and compared to the monotonic tensile tests at different strain rates ranging from 10-4to 10-1s-1. To understand the effect of anisotropy, samples were taken along 0° and 90° to rolling direction (RD) for both the alloys. Improvement in ductility of different levels at all the strain rates was observed in both the alloys when stress relaxation steps were introduced as compared to monotonic tests. However there is not much change in the flow stress as well as in strain hardening behaviour of the alloys. The true stress-true strain curves of Grade 4 samples taken in 90° to RD exhibited discontinuous yielding phenomenon after the yield point, which is termed as a yield-point elongation (YPE). The improvement in ductility of the Cp-Ti alloys can be linked to recovery process occurring during the stress relaxation steps which resulted in the improvement in ductility after repeated interrupted tensile tests. The paper presents and summarise the results based on the stress relaxation for the two different alloys.


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