Response and failure of fiber metal laminates subjected to high strain rate tensile loading

2018 ◽  
Vol 53 (11) ◽  
pp. 1489-1506 ◽  
Author(s):  
Ankush P Sharma ◽  
Sanan H Khan ◽  
Venkitanarayanan Parameswaran
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Glass Fiber ◽  
High Speed ◽  
High Strain ◽  
Image Correlation ◽  
Fiber Metal Laminates ◽  
Rate Dependent ◽  
Dependent Behavior ◽  
Fiber Metal

The tensile behavior of fiber metal laminates consisting of layers of aluminum 2024-T3 alloy and glass fiber reinforced composites under high strain rate loading is investigated. Fiber metal laminates having four different layups, but all having the same total metal layer thickness, were fabricated using a combined hand lay-up cum vacuum bagging method. The fiber metal laminate specimens were loaded in high strain rate tension using a split Hopkinson tensile bar. The rate-dependent behavior of the glass fiber composite was also obtained as baseline data. The strain on the gage area of the specimen was measured directly using high-speed digital image correlation. Another high-speed camera was used to capture the sequence of damage by viewing the specimen edgewise. The results indicated that the strength of the fiber metal laminates increased at high strain rates primarily due to the rate-dependent behavior of the composite used. The response was also influenced by the distribution of the metallic layers in the fiber metal laminates. The failure in the case where the individual composite layers were separated by metallic layers was more progressive in nature.

Effect of high strain rate on tensile response and failure analysis of titanium/glass fiber reinforced polymer composites

2021 ◽  
pp. 002199832110188
Author(s):  
Ankush P Sharma ◽  
R Velmurugan
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Glass Fiber ◽  
High Strain ◽  
Failure Strain ◽  
Image Correlation ◽  
Fiber Reinforced ◽  
Tensile Response ◽  
Glass Fiber Reinforced ◽  
Composite Layers

The high strain rate tensile response of titanium-based fiber metal laminates (FMLs), consisting of layers of titanium Ti-6Al-4V alloy sheet and glass fiber reinforced composites, is examined. A hand layup method is used to fabricate four different layups of FMLs, exhibiting the same thickness of the total metal layer. A split Hopkinson tensile bar apparatus is used to load titanium and composite under a high strain rate to obtain baseline data. High-speed digital image correlation is used to measure the strain directly on the specimen gage region. The elastic-plastic response of FMLs up to maximum stress is predicted by the classical laminated plate model and orthotropic plasticity model. This is followed by a behavior considering the mechanics of delamination. The results show that the layup sequence of titanium-based FMLs considerably affects the failure behavior of composites following ultimate strength. This strength increases at high strain rates and seems higher for titanium-based FMLs than aluminium-based FMLs. This is primarily caused by the rate-dependent response of the titanium and composite. The failure strain of glass fiber reinforced epoxy (GFRP) constituent, failure strain, and toughness of FMLs are affected by isolating composite layers by metallic layers within FMLs and are found to be rate sensitive. Isolation of composite layers from one another by metallic layers results in more progressive failure of FMLs. The proposed models are validated with experiments of aluminium-based FMLs available in the literature.

scholarly journals High-Strain-Rate Shear Testing Applied to Ti-6Al-4V

2010 ◽  
Vol 89-91 ◽  
pp. 437-442 ◽  
Author(s):  
Jan Peirs ◽  
Patricia Verleysen ◽  
Joris Degrieck
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Speed ◽  
High Strain ◽  
Image Correlation ◽  
Experimental Techniques ◽  
Shear Behaviour ◽  
Split Hopkinson ◽  
Set Up ◽  
Static Behaviour

In this contribution, two experimental techniques to study the dynamic shear behaviour of metals are presented and applied to Ti-6Al-4V. For bulk materials hat-shaped specimens are subjected to a high-strain-rate load in a split Hopkinson compression bar set-up. For sheet materials a purpose-developed, novel shear specimen geometry, is loaded in a Hopkinson tensile bar set-up. The value of both techniques to assess the dynamic material behaviour is discussed. The experiments are optimized by means of numerical simulations. Digital image correlation is used to extract the specimen deformation from high speed camera recordings. It is shown that the dynamic behaviour, including fracture of Ti-6Al-4V differs considerably from the static behaviour. Both experimental techniques gain complementary information.

scholarly journals Experimental methodology for the measurement of plasticity on metals at high strain-rates

2018 ◽  
Vol 183 ◽  
pp. 02063 ◽  
Author(s):  
Alexander Sancho ◽  
Mike J. Cox ◽  
Giles Aldrich-Smith ◽  
Tim Cartwright ◽  
Catrin M. Davies ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Speed ◽  
High Strain ◽  
Tensile Tests ◽  
Detection Algorithm ◽  
Image Correlation ◽  
Experimental Methodology ◽  
Tensile Behaviour ◽  
Strain Rates

An experimental methodology has been developed for the tensile characterisation of ductile isotropic metals at high strain-rate. This study includes the region beyond plastic instability or necking, which is rarely analysed for conventional applications. The research explores an imaging technique used to track the geometry of the specimen during tensile tests and calculate true local values of stress and strain by applying Bridgman theory [1]. To improve the quality of the images taken at high strain-rate an in-situ high speed shadowgraph technique has been developed, and to obtain better results from the images a sub-pixel accuracy edge detection algorithm has been implemented. The technique has been applied to an austenitic stainless steel. Its tensile behaviour has been assessed by testing round samples at strain-rates ranging from quasi-static to ~103 s-1. The results obtained with the proposed methodology have been validated by comparison with more conventional techniques such as video-extensometer and digital image correlation in the pre-necking region and good performance even at the highest strain-rate tested has been proved.

The Effect of Strain Rate on the Material Characteristics of Nickel-Based Superalloy Inconel 718

2007 ◽  
Vol 340-341 ◽  
pp. 283-288 ◽  
Author(s):  
Jung Han Song ◽  
Hoon Huh
Keyword(s):  
Dynamic Response ◽  
High Strain Rate ◽  
Strain Rate ◽  
Turbine Blade ◽  
Inconel 718 ◽  
High Speed ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Experimental Results ◽  
Stress Wave Propagation

The dynamic response of the turbine blade materials is indispensable for analysis of erosions of turbine blades as a result of impulsive loading associated with gas flow. This paper is concerned with the dynamic material properties of the Inconel 718 alloy which is widely used in the high speed turbine blade. The dynamic response at the corresponding level of the strain rate should be acquired with an adequate experimental technique and apparatus due to the inertia effect and the stress wave propagation. In this paper, the dynamic response of the Inconel 718 at the intermediate strain rate ranged from 1/s to 400/s is obtained from the high speed tensile test and that at the high strain rate above 1000/s is obtained from the split Hopkinson pressure bar test. The effects of the strain rate on the dynamic flow stress, the strain rate sensitivity and the failure elongation are evaluated with the experimental results. Experimental results from both the quasi-static and the high strain rate up to 3000/s are interpolated in order to construct the constitutive relation that should be applied to simulate the dynamic behavior of the turbine blade made of the Inconel 718.

Research on Numerical Algorithm of Constitutive Equation under High Speed Deformation in Hadfield Steel

2012 ◽  
Vol 562-564 ◽  
pp. 688-692 ◽  
Author(s):  
Deng Yue Sun ◽  
Jing Li ◽  
Fu Cheng Zhang ◽  
Feng Chao Liu ◽  
Ming Zhang
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Deformation Behavior ◽  
High Speed ◽  
High Strain ◽  
Equivalent Stress ◽  
Hadfield Steel ◽  
Stress And Strain ◽  
Strain Rates ◽  
The Finite Element Method

The influence of the strain rate on the plastic deformation of the metals was significant during the high strain rate of loading. However, it was very difficult to obtain high strain rate data (≥ 104 s-1) by experimental techniques. Therefore, the finite element method and iterative method were employed in this study. Numerical simulation was used to characterise the deformation behavior of Hadfield steel during explosion treatment. Base on experimental data, a modified Johnson-Cook equation for Hadfield steel under various strain rate was fitted. The development of two field variables was quantified during explosion hardening: equivalent stress and strain rates.

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