scholarly journals The Off-Axis IBII Test for Composites

2020 ◽  
Author(s):  
S. Parry ◽  
L. Fletcher ◽  
F. Pierron
Keyword(s):  
Shear Modulus ◽  
Strain Rate ◽  
High Strain ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Published Data ◽  
Shear Moduli ◽  
Test Methodology ◽  
Split Hopkinson

Abstract Composite components regularly experience dynamic loads in service. Despite this, it is still difficult to obtain accurate mechanical properties of composite materials under high strain rate conditions. In this study, a new application of the Image-Based Inertial Impact (IBII) test methodology was developed, to generate an accurate in-plane transverse and shear moduli dataset from unidirectional (UD) off-axis composite specimens. The obtained dataset was consistent across different sample configurations, where results from the UD45$$^{\circ }$$ ∘ off-axis specimens agreed well with the UD90$$^{\circ }$$ ∘ values. Validation of the shear modulus identification was also undertaken by comparing the results from the UD90$$^{\circ }$$ ∘ and UD45$$^{\circ }$$ ∘ specimens with a multi-directional (MD) configuration. Here, it was found that MD±45$$^{\circ }$$ ∘ specimen shear modulus values where marginally lower than that from the UD specimens, in accordance with the lower fibre volume fraction of the MD laminate. Low strain rate sensitivities in the $$0.5-2\times$$ 0.5 - 2 × 10$$^{3}$$ 3  $$\hbox {s}^{-1}$$ s - 1 regime evidenced in this work suggest previously published data (often from split-Hopkinson bar tests) may include both a material and system i.e. testing apparatus response.

scholarly journals Thermal conductivity of textile reinforcements for composites

2018 ◽  
Vol 1 ◽  
pp. 251522111775115 ◽  
Author(s):  
Yue El-Hage ◽  
Simon Hind ◽  
François Robitaille
Keyword(s):  
Thermal Conductivity ◽  
Carbon Fibre ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Three Dimensional ◽  
Fibre Volume ◽  
Published Data ◽  
Manufacturing Processes ◽  
Composites Manufacturing ◽  
The Relationship

Thermal conductivity data for dry carbon fibre fabrics are required for modelling heat transfer during composites manufacturing processes; however, very few published data are available. This article reports in-plane and through-thickness thermal conductivities measured as a function of fibre volume fraction ( Vf) for non-crimp and twill carbon reinforcement fabrics, three-dimensional weaves and reinforcement stacks assembled with one-sided carbon stitch. Composites made from these reinforcements and glass fibre fabrics are also measured. Clear trends are observed and the effects of Vf, de-bulking and vacuum are quantified along with orthotropy ratios. Limited differences between the conductivity of dry glass and carbon fibre fabrics in the through-thickness direction are reported. An unexpected trend in the relationship between that quantity and Vf is explained summarily through simple simulations.

scholarly journals Strain Rate Effects on Tensile and Compressive Behaviour of Woven-Knitting Glass/Epoxy Composites

2013 ◽  
Vol 22 (1) ◽  
pp. 096369351302200 ◽  
Author(s):  
Mehmet Aktas ◽  
H. Ersen Balcioğlu ◽  
Gürhan Külahli
Keyword(s):  
Strain Rate ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Testing Machine ◽  
Fibre Volume ◽  
Woven Fabric ◽  
Epoxy Composites ◽  
Compressive Properties ◽  
Compressive Behaviour ◽  
Low Strain Rate

The main purpose of this study was to investigate the tensile and compressive behaviour of woven-knitting glass/epoxy composites under low strain rate by using UTEST testing machine with capacity of 50kN. The strain rate values were selected as 0.005, 0.0005 and 0.00005s−1. The effect of knitting direction as wale, course and 45° and knitting structure as rib and milano on the tensile and compressive behaviour of woven-knitting glass/epoxy composites under low strain rate was also discussed. The woven-knitting composite samples were tested under uni-axial tensile and compressive loading. The woven-knitting composites have eight layer with woven fabric (W), rib (R) and milano (M) knitting fabrics as (W2/R2)S and (W2/M2)S. The woven-knitting composites were manufactured by hand lay-up method. The fibre volume fraction and thickness of manufactured woven-knitting composites were measured 65% in weight and 2.9mm, respectively. The experimental results showed that the tensile and compressive properties of woven-knitting glass/epoxy composites decrease from 0.005 s−1 to 0.00005s−1. The tensile properties in all directions of plate with rib knitting were obtained higher than the plate with milano knitting. However, the highest compressive properties were obtained from plate with rib knitting in course direction.

scholarly journals High Strain Rate Characterization of Shock Absorbing Materials for Landmine Protection Concepts

2003 ◽  
Vol 10 (3) ◽  
pp. 179-186 ◽  
Author(s):  
Jennifer McArthur ◽  
Christopher Salisbury ◽  
Duane Cronin ◽  
Michael Worswick ◽  
Kevin Williams
Keyword(s):  
Strain Rate ◽  
High Strain ◽  
Dynamic Testing ◽  
Stress Wave Propagation ◽  
Published Data ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars ◽  
Dynamic Material Properties ◽  
Foamed Metals

Numerical modelling of footwear to protect against anti-personnel landmines requires dynamic material properties in the appropriate strain rate regime to accurately simulate material response. Several materials (foamed metals, honeycombs and polymers) are used in existing protective boots, however published data at high strain rates is limited.Dynamic testing of several materials was performed using Split Hopkinson Pressure Bars (SHPB) of various sizes and materials. The data obtained from these tests has been incorporated into material models to predict the initial stress wave propagation through the materials. Recommendations for the numerical modeling of these materials have also been included.

Effect of fibre content on the mechanical properties of hemp fibre woven fabrics/polypropylene composite laminates

2021 ◽  
pp. 096739112110239
Author(s):  
Sheedev Antony ◽  
Abel Cherouat ◽  
Guillaume Montay
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Composite Laminates ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Woven Fabrics ◽  
Fibre Content ◽  
Viscoelastic Behaviour ◽  
Hemp Fibre

Nowadays natural fibre composites have gained great significance as reinforcements in polymer matrix composites. Composite material based on a polymer matrix reinforced with natural fibres is extensively used in industry due to their biodegradability, recyclability, low density and high specific properties. A study has been carried out here to investigate the fibre volume fraction effect of hemp fibre woven fabrics/PolyPropylene (PP) composite laminates on the tensile properties and impact hammer impact test. Initially, composite sheets were fabricated by the thermal-compression process with desired number of fabric layers to obtain composite laminates with different fibre volume fraction. Uniaxial, shear and biaxial tensile tests were performed and mechanical properties were calculated. Impact hammer test was also carried out to estimate the frequency and damping parameters of stratified composite plates. Scanning Electron Microscope (SEM) analysis was performed to observe the matrix and fibre constituent defects. Hemp fabrics/PP composite laminates exhibits viscoelastic behaviour and as the fibre volume fraction increases, the viscoelastic behaviour decreases to elastic behaviour. Due to this, the tensile strength increases as the fibre content increases. On the other hand, the natural frequency increases and damping ratio decrease as the fibre volume fraction increases.

scholarly journals Insulation Characteristics of Sisal Fibre/Epoxy Composites

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
A. Shalwan ◽  
M. Alajmi ◽  
A. Alajmi
Keyword(s):  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Thermal Characteristics ◽  
Fibre Volume ◽  
Point Of View ◽  
Natural Fibres ◽  
Epoxy Composites ◽  
Ongoing Research ◽  
Sisal Fibre ◽  
The Impact

Using natural fibres in civil engineering is the aim of many industrial and academics sectors to overcome the impact of synthetic fibres on environments. One of the potential applications of natural fibres composites is to be implemented in insulation components. Thermal behaviour of polymer composites based on natural fibres is recent ongoing research. In this article, thermal characteristics of sisal fibre reinforced epoxy composites are evaluated for treated and untreated fibres considering different volume fractions of 0–30%. The results revealed that the increase in the fibre volume fraction increased the insulation performance of the composites for both treated and untreated fibres. More than 200% insulation rate was achieved at the volume fraction of 20% of treated sisal fibres. Untreated fibres showed about 400% insulation rate; however, it is not recommended to use untreated fibres from mechanical point of view. The results indicated that there is potential of using the developed composites for insulation purposes.

New Development of Cattail Fibre in Composite Uses

2013 ◽  
Vol 746 ◽  
pp. 385-389
Author(s):  
Li Yan Liu ◽  
Yu Ping Chen ◽  
Jing Zhu
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Environmental Benefits ◽  
Bending Properties ◽  
New Development ◽  
Original Plant ◽  
Reinforcing Material ◽  
Pp Composites

This paper is aiming to develop the cattail fibre as reinforcing material due to its environmental benefits and excellent physical and insulated characteristics. The current work is concerned with the development of the technical fibres from the original plant and research on their reinforcing properties in the innovative composites. Polypropylene (PP) fibre was used as matrix in this research which was fabricated into fibre mats with cattail fibre together with different fibre volume fractions. Cattail fibre reinforced PP laminates were manufactured and compared with jute/PP composites. The tensile and bending properties of laminates were tested. The SEM micrographs of fracture surface of the laminates were analyzed as well. The results reveal that the tensile and bending properties of cattail/PP laminates are closed to those of jute/PP composites. The mechanical properties of cattail/jute/PP laminates with fibre volume fraction of 20/35/45 is betther than those of laminate reinforced with cattail fibers.

Dynamic Behaviors of near β-Type Ti-5Al-5Mo-5V-3Cr Titanium Alloys under High Strain Rate

2015 ◽  
Vol 816 ◽  
pp. 795-803
Author(s):  
Yan Ling Wang ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Rui Liu
Keyword(s):  
Strain Rate ◽  
Titanium Alloys ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Failure Behavior ◽  
Hopkinson Pressure Bar ◽  
Fracture Failure ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Dynamic Loading Conditions

The mechanical properties and fracture failure behavior of the near β-type Ti-5Al-5Mo-5V-3Cr-X (X = 1Fe or 1Zr) titanium alloys were studied by Split Hopkinson Pressure Bar (SHPB) experiment under the dynamic loading conditions at a strain rate of 1.5 × 103 s-1–5.0 × 103 s-1. Results showed that the SHPB specimen fractured in the direction of maximum shearing stress at an angle of 45° with the compression axis. The fracture surface revealed the shear and tension zones with cleavage steps and parabolic dimples. Severe early unloading was observed on the Ti-5553 alloy under a strain rate of 4,900 s-1 loading condition, and the dynamic property of the Ti-55531Zr alloy was proved to be the optimal.

scholarly journals The Mechanical Properties of Steel-Polypropylene Fibre Composites Concrete (HyFRCC)

2015 ◽  
Vol 773-774 ◽  
pp. 949-953 ◽  
Author(s):  
Izni Syahrizal Ibrahim ◽  
Wan Amizah Wan Jusoh ◽  
Abdul Rahman Mohd Sam ◽  
Nur Ain Mustapa ◽  
Sk Muiz Sk Abdul Razak
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Volume Fraction ◽  
Concrete Strength ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Polypropylene Fibre ◽  
Experimental Results

This paper discusses the experimental results on the mechanical properties of hybrid fibre reinforced composite concrete (HyFRCC) containing different proportions of steel fibre (SF) and polypropylene fibre (PPF). The mechanical properties include compressive strength, tensile strength, and flexural strength. SF is known to enhance the flexural and tensile strengths, and at the same time is able to resist the formation of macro cracking. Meanwhile, PPF contributes to the tensile strain capacity and compressive strength, and also delay the formation of micro cracks. Hooked-end deformed type SF fibre with 60 mm length and fibrillated virgin type PPF fibre with 19 mm length are used in this study. Meanwhile, the concrete strength is maintained for grade C30. The percentage proportion of SF-PPF fibres are varied in the range of 100-0%, 75-25%, 50-50%, 25-75% and 0-100% of which the total fibre volume fraction (Vf) is fixed at 0.5%. The experimental results reveal that the percentage proportion of SF-PPF fibres with 75-25% produced the maximum performance of flexural strength, tensile strength and flexural toughness. Meanwhile, the percentage proportion of SF-PPF fibres with 100-0% contributes to the improvement of the compressive strength compared to that of plain concrete.

scholarly journals Postheated Model of Confined High Strength Fibrous Concrete

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Kaleem A. Zaidi ◽  
Umesh K. Sharma ◽  
N. M. Bhandari ◽  
P. Bhargava
Keyword(s):  
High Temperature ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
High Strength ◽  
Fibre Volume ◽  
Experimental Results ◽  
Confined Concrete ◽  
Structural Safety ◽  
Stress Strain ◽  
Fibrous Concrete

HSC normally suffers from low stiffness and poor strain capacity after exposure to high temperature. High strength confined fibrous concrete (HSCFC) is being used in industrial structures and other high rise buildings that may be subjected to high temperature during operation or in case of an accidental fire. The proper understanding of the effect of elevated temperature on the stress-strain relationship of HSCFC is necessary for the assessment of structural safety. Further stress-strain model of HSCFC after exposure to high temperature is scarce in literature. Experimental results are used to generate the complete stress-strain curves of HSCFC after exposure to high temperature in compression. The variation in concrete mixes was achieved by varying the types of fibre, volume fraction of fibres, and temperature of exposure from ambient to 800°C. The degree of confinement was kept constant in all the specimens. A comparative assessment of different models on the high strength confined concrete was also conducted at different temperature for the accuracy of proposed model. The proposed empirical stress-strain equations are suitable for both high strength confined concrete and HSCFC after exposure to high temperature in compression. The predictions were found to be in good agreement and well fit with experimental results.

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