scholarly journals Homogenization effects on simulated pultruded glass fibre reinforced laminate under compression – from static to dynamic models

2021 ◽  
Vol 250 ◽  
pp. 02034
Author(s):  
Nazanin Pournoori ◽  
Oscar Rodera García ◽  
Jarno Jokinen ◽  
Mikko Hokka ◽  
Mikko Kanerva
Keyword(s):  
Glass Fibre ◽  
Dynamic Models ◽  
Split Hopkinson Pressure Bar ◽  
Element Model ◽  
High Rate ◽  
Single Element ◽  
Hopkinson Pressure Bar ◽  
Computationally Efficient ◽  
Glass Fibre Reinforced ◽  
Homogenized Model

This study presents a numerical analysis of failure in pultruded glass fibre reinforced polymer (GFRP) with three reinforcement layers, subjected to out-of-plane compressive loadings at low and high strain rates (10-3 s-1 and 103 s-1). The simulations targets to a computationally efficient homogenization with different element types and sizes. A single-element model was created to demonstrate the highest level of homogenization. The material properties in the homogenized model were calculated using the ESAComp (Altair) software. The 3D Hashin failure criterion was implemented as a user-defined subroutine into the finite element method using Abaqus (Simulia/Dassault Systemes) to predict the failure. The comparison between different meshes and elements shows the sufficient accuracy of the homogenized model to predict the material response at the damage onset, but the location of the crack was not accurately predicted as expected. High-rate impact simulations of the Split Hopkinson Pressure Bar tests showed that the mesh does not significantly affect the failure (strain) predicted by the homogenized model.

Flexural behaviour of glass fibre-reinforced plastic laminates with drilled hole

2012 ◽  
Vol 226 (2) ◽  
pp. 149-158 ◽  
Author(s):  
P K Rakesh ◽  
I Singh ◽  
D Kumar
Keyword(s):  
Glass Fibre ◽  
Polymer Matrix Composites ◽  
Element Model ◽  
Hole Drilling ◽  
Loading Conditions ◽  
Flexural Behaviour ◽  
Reinforced Plastic ◽  
Glass Fibre Reinforced Plastic ◽  
Glass Fibre Reinforced ◽  
Plastic Laminates

Drilling is one of the most commonly used process for hole making. Drilling of polymer matrix composites (PMCs) causes substantial damage around the drilled hole. Drilling-induced damage not only decreases the strength of the composite laminate with hole, but it also deteriorates the long-term performance of the PMC laminates under different loading conditions. In the present research investigation, the flexural behaviour of the glass fibre-reinforced plastic laminates with drilled hole was experimentally investigated under three-point loading conditions. The results of the experimental investigation were compared with those of the finite element model and were found to be in close agreement.

Simultaneous effects of strain rate and temperature on mechanical response of fabricated Mg–SiC nanocomposite

2019 ◽  
Vol 54 (5) ◽  
pp. 659-668 ◽  
Author(s):  
K Rahmani ◽  
GH Majzoobi ◽  
A Atrian
Keyword(s):  
Strain Rate ◽  
Mechanical Response ◽  
Split Hopkinson Pressure Bar ◽  
High Rate ◽  
Dynamic Tests ◽  
Hopkinson Pressure Bar ◽  
Compaction Temperature ◽  
Static Tests ◽  
Split Hopkinson ◽  
Pressure Bar

Mg–SiC nanocomposite samples were fabricated using split Hopkinson pressure bar for different SiC volume fractions and under different temperature conditions. The microstructures and mechanical properties of the samples including microhardness and stress–strain curves were captured from quasi-static and dynamic tests carried out using Instron and split Hopkinson pressure bar, respectively. Nanocomposites were produced by hot and high-rate compaction method using split Hopkinson pressure bar. Temperature also significantly affects relative density and can lead to 2.5% increase in density. Adding SiC-reinforcing particles to samples increased their Vickers microhardness from 46 VH to 68 VH (45% increase) depending on the compaction temperature. X-ray diffraction analysis showed that by increasing temperature from 25℃ to 450℃, the Mg crystallite size increases from 37 nm to 72 nm and decreases the lattice strain from 45% to 30%. In quasi-static tests, the ultimate compressive strength for the compaction temperature of 450℃ was improved from 123% for Mg–0 vol.% SiC to 200% for the Mg–10 vol.% SiC samples compared with those of the compaction at room temperature. In dynamic tests, the ultimate strength for Mg–10 vol.% SiC sample compacted at high strain rate increased remarkably by 110% compared with that for Mg–0 vol.% SiC sample compacted at low strain rate.

Temperature Rise in Polymeric Materials During High Rate Deformation

2008 ◽  
Vol 75 (1) ◽  
Author(s):  
M. Garg ◽  
A. D. Mulliken ◽  
M. C. Boyce
Keyword(s):  
Strain Rate ◽  
Temperature Rise ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Polymeric Materials ◽  
Test System ◽  
High Rate ◽  
Single Element ◽  
Strain Rates ◽  
Work Of Deformation

Many polymeric materials undergo substantial plastic strain prior to failure. Much of this post yield deformation is dissipative and, at high strain rates, will result in a substantial temperature rise in the material. In this paper, an infrared (IR) detector system is constructed to measure the rise in temperature of a polymer during high strain rate compression testing. Temperature measurements were made using a high-speed mercury-cadmium-telluride (HgCdTe) single-element photovoltaic detector sensitive in the mid-infrared spectrum (6–12μm), while mechanical deformation was accomplished in a split Hopkinson pressure bar (SHPB). Two representative polymers, an amorphous thermoplastic (polycarbonate (PC)) and a thermoset epoxy (EPON 862/W), were tested in uniaxial compression at strain rates greater than 1000s−1 while simultaneously measuring the specimen temperature as a function of strain. For comparison purposes, analogous measurements were conducted on these materials tested at a strain rate of 0.5s−1 on another test system. The data are further reduced to energy quantities revealing the dissipative versus storage character of the post yield work of deformation. The fraction of post yield work that is dissipative was found to be a strong function of strain for both polymers. Furthermore, a greater percentage of work is found to be dissipative at high rates of strain (>1000s−1) than at the lower rate of strain (0.5s−1) for both polymers; this is consistent with the need to overcome an additional energy barrier to yield at strain rates greater than 100s−1 in these two polymers. The highly cross-linked thermoset polymer was found to store a greater percentage of the post yield work of deformation than the physically entangled thermoplastic.

High Strain Rate and High Temperature Behavior of Ti–6Al–4V Alloy Under Compressive Loading

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Nitin B. Bhalerao ◽  
Suhas S. Joshi ◽  
N. K. Naik
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Equilibrium ◽  
Dynamic Properties ◽  
Weight Ratio ◽  
High Rate ◽  
Material Strength ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Two Phase

The titanium alloy (grade 5) is a two-phase material, which finds significant applications in aerospace, medical, marine fields, owing to its superior characteristics like high strength-to-weight ratio, excellent corrosion resistance, and good formability. Hence, the dynamic characteristics of the Ti-6Al-4V alloy are an important area to study. A compressive split Hopkinson pressure bar (SHPB) was used to evaluate the dynamic properties of Ti-6Al-4V alloy under various strain rates between 997 and 1898s−1, and at temperatures between −10 °C and 320 °C. It was evident that the material strength is sensitive to both strain rate and temperature; however, the latter is more predominant than the former. The microstructure of the deformed samples was examined using electron back-scattered diffraction (EBSD). The microscopic observations show that the dynamic impact characteristics of the alloy are higher at higher strain rates than at quasi-static strain rates. The SHPB tests show that the force on the transmitter bar is lower than the force on the incident bar. This indicates that the dynamic equilibrium cannot be achieved during high rate of damage evolution. Various constants in Johnson–Cook (JC) model were evaluated to validate the results. An uncertainty analysis for the experimental results has also been presented.

Shock Induced Deformation and Damage in Rat Brain Slices

2010 ◽  
Author(s):  
Jiwoon Kwon ◽  
Sung J. Lee ◽  
Ghatu Subhash ◽  
Michael King ◽  
Malisa Sarntinoranont
Keyword(s):  
Brain Tissue ◽  
High Speed ◽  
Shock Loading ◽  
Split Hopkinson Pressure Bar ◽  
Brain Slices ◽  
High Rate ◽  
Hopkinson Pressure Bar ◽  
Post Traumatic Stress ◽  
Tissue Slices ◽  
High Rate Loading

Shock-induced traumatic brain injury (TBI) and post traumatic stress disorder (PTSD) have received increasing attention because many soldiers returning from Iraq and Afghanistan suffer from these disorders. The shock loading duration is typically on the order of few hundred microseconds and hence the strain rate of deformation is very high. Therefore, in the current study, high-rate loading experiments were conducted on brain tissue slices which mimic loading durations encountered in shock loading [1]. The polymer split Hopkinson pressure bar (PSHPB) was used to generate high rate loading as a high speed digital camera captured the deformation of brain tissue. To further clarify initial injury events, post-test damage was assessed through histological studies. This experimental model provides the opportunity for time-resolved visualization of actual tissue deformation thus allowing improved ability to isolate damage-sensitive tissue regions.

scholarly journals Development of a constitutive model for DPX2 explosive

2018 ◽  
Vol 183 ◽  
pp. 01059
Author(s):  
Philip Church ◽  
Peter Gould ◽  
David Williamson
Keyword(s):  
Constitutive Model ◽  
Impact Loading ◽  
Split Hopkinson Pressure Bar ◽  
Model Development ◽  
Tensile Tests ◽  
High Rate ◽  
Hopkinson Pressure Bar ◽  
Static Compression ◽  
Physically Based ◽  
Stress States

There is a significant challenge in simulating the behaviour of PBXs under high strain rate impact loading. A Porter-Gould physically based constitutive model has been developed for the DPX2 explosive. A series of quasi-static compression and tensile tests over a range of temperatures were performed together with DMA tests to calibrate the model. In particular tests were performed for different L/D ratios to understand the complex localisation and damage behaviour of the material. High rate tests on the compression Split Hopkinson Pressure Bar (SHPB) for a range of temperatures were then used for validation of the model under idealised stress states. Some model development is still required, particularly at lower temperatures near the glass transition temperature. In addition a series of classical Taylor Tests were used to validate the model under impact loading conditions at room temperature. The DYNA3D simulations gave very good results compared to the experiments for these impact conditions.

scholarly journals A Simple Rate–Temperature Dependent Hyperelastic Model Applied to Neoprene Rubber

2020 ◽  
Vol 6 (3) ◽  
pp. 336-347
Author(s):  
A. R. Trivedi ◽  
C. R. Siviour
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
High Rate ◽  
Hopkinson Pressure Bar ◽  
Temperature Dependent ◽  
Temperature Superposition ◽  
High Strain Rate Deformation ◽  
Split Hopkinson ◽  
Hyperelastic Model ◽  
Pressure Bar ◽  
Two Parameter

Abstract Rubber is widely used in engineering applications in which it may be subjected to impact loading leading to high strain rate deformation. This resulting deformation may occur at a variety of temperatures, notwithstanding the self-heating of the material. For this reason, it is necessary to study the mechanical behaviour of these materials over a range of loading conditions. The strong rate and temperature dependence of their properties provides a further motivation for this understanding. In this paper, the relationships between the response of a neoprene rubber at various strain rates and temperatures are investigated, and a simple model making use of the time–temperature superposition (TTS) principle proposed to describe the material behaviour. As it is challenging to obtain high rate data on rubbery materials using conventional apparatus, such as the split-Hopkinson pressure bar (SHPB), the simple two parameter hyperelastic model proposed here provides a useful complementary tool to interrogate the response.

Development of a Material Constitutive for High-Rate Using a Combined Experiment/Computation Method

2004 ◽  
Vol 261-263 ◽  
pp. 269-276
Author(s):  
J.F. Lu ◽  
Zhuo Zhuang ◽  
K. Shimamura
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Equivalent Strain ◽  
High Rate ◽  
Computation Method ◽  
Failure Behavior ◽  
Hopkinson Pressure Bar ◽  
Material Constants ◽  
Split Hopkinson ◽  
Pressure Bar

To describe the high-rate behaviour of metals, a revised form of the classic Johnson-Cook strength model with unknown material constants has been used. The 1D stress-strain relations as well as the effects of strain, strain rate and temperature are examined by Split Hopkinson Pressure Bar (SHPB) test. The undetermined material constants are solved using a variable-dissociation method. The element failure criterion based on maximum equivalent strain is also introduced to estimate the material failure behavior under high strain rate. A corresponding user-defined material subroutine (UMAT) has been developed for revised Johnson-Cook model, which is implemented into ABAQUS. Using this implicit scheme, several groups of finite element simulations under different strain rates are completed in ABAQUS/Standard. The results agree well with the test data and other results by explicit code.

A Study of the Dynamic Behavior of Elastomeric Materials Using Finite Elements

1996 ◽  
Vol 118 (4) ◽  
pp. 503-508 ◽  
Author(s):  
G. E. Vallee ◽  
Arun Shukla
Keyword(s):  
Finite Element ◽  
Dynamic Behavior ◽  
Split Hopkinson Pressure Bar ◽  
Material Model ◽  
Element Model ◽  
Material Behavior ◽  
Hopkinson Pressure Bar ◽  
Material Models ◽  
Finite Element Program ◽  
Elastomeric Materials

A numerical method is described for determining a dynamic finite element material model for elastomeric materials loaded primarily in compression. The method employs data obtained using the Split Hopkinson Pressure Bar (SHPB) technique to define a molecular constitutive model for elastomers. The molecular theory is then used to predict dynamic material behavior in several additional deformation modes used by the ABAQUS/Explicit (Hibbitt, Karlsson, and Sorenson, 1993a) commercial finite element program to define hyperelastic material behavior. The resulting dynamic material models are used to create a finite element model of the SHPB system, yielding insights into both the accuracy of the material models and the SHPB technique itself when used to determine the dynamic behavior of elastomeric materials. Impact loading of larger elastomeric specimens whose size prohibits examination by the SHPB technique are examined and compared to the results of dynamic load-deflection experiments to further verify the dynamic material models.

Sign in / Sign up

Export Citation Format

Share Document