The Effect of a Coupling Agent on the Impact Behaviour of Flax Fibre Composites

2021 ◽  
pp. 1-17
Author(s):  
Cihan Kaboglu ◽  
Jun Liu ◽  
Haibao Liu ◽  
Pietro Russo ◽  
Giorgio Simeoli ◽  
...  
Keyword(s):  
Impact Loading ◽  
Coupling Agent ◽  
Testing Machine ◽  
Natural Fibers ◽  
Flax Fiber ◽  
Image Correlation ◽  
Impact Tests ◽  
Out Of Plane ◽  
Plane Displacement ◽  
The Impact

Abstract The effects of a coupling agent on the behavior of flax fiber reinforced composites have been investigated by testing the specimens under both quasi-static indentation and high velocity impact loading. The specimens are manufactured embedding a commercial flax fiber fabric in a polypropylene (PP) matrix, neat and pre-modified with a maleic anhydride grafted PP, the latter acting as a coupling agent to enhance the interfacial adhesion. Quasi-static (QS) compressive tests were performed using a dynamometer testing machine equipped with a high-density polyethylene indenter having the same geometry of the projectile employed in the impact tests. The impact tests were conducted setting three different impact velocities. Digital Image Correlation maps of out-of-plane displacement were employed to compare the specimens with and without the coupling agent. The QS testing results indicate that the coupling agent has an enhancing influence on the bending stiffness of tested flax composites. The testing results show that the coupling agent improves the mechanical behavior by decreasing the out-of-plane displacement under impact loading. This approach gives rise to new materials potentially useful for applications where impact performance is desired whilst also providing an opportunity for the incorporation of natural fibers to produce a lightweight composite.

scholarly journals Hybrid composite sandwich panels under blast and impact loading

2018 ◽  
Vol 183 ◽  
pp. 02003
Author(s):  
Emily Rolfe ◽  
Hari Arora ◽  
Paul A. Hooper ◽  
John P. Dear
Keyword(s):  
Carbon Fibre ◽  
Glass Fibre ◽  
Blast Loading ◽  
Impact Testing ◽  
Image Correlation ◽  
Small Scale ◽  
Composite Sandwich ◽  
Out Of Plane ◽  
Plane Displacement ◽  
The Impact

Naval vessels may undergo high strain rate loading, including impact, wave slamming and blast loading. Predicting the behaviour of composite sandwich structures to such loading is complicated, hence representative experiments are required. Two panels with hybrid carbon-and glass-fibre skins were fabricated and subjected to full-scale air blast loading. The panels were 1.7 × 1.5 m in size and were subjected to a 100 kg nitromethane charge at a stand-off distance of 15 m. 3D Digital Image Correlation (DIC) was implemented behind each of the panels to record the full-field out-of-plane displacement of the panels. In addition, the panels were instrumented with foil strain gauges on the front skins to record the response of the panel side in contact with the blast. The results revealed that the combination of glass-and carbon-fibre improves the blast resilience when compared to previous blast testing on panels with exclusively glass-fibre or carbon-fibre skins. However, the order in which the glass-and carbon-fibre layers were arranged did not have a significant effect on the overall panel performance. In addition, panels with the same hybrid skins were subjected to high velocity impact testing. An aluminium projectile with 25 mm diameter was fired at small scale panels (160 × 160 mm) using a laboratory gas gun at a velocity of 78 ms−1. 3D DIC was again used to record the out-of-plane displacement of these panels. In contrast to the blast experiment, the impact results showed that the order in which glass-and carbon-fibres were arranged did affect both the out-of-plane displacement and damage to the panels. The least damage occurred when glass-fibre layers were placed on the outermost layers impacted by the projectile.

scholarly journals Sensor Integrated Load-Bearing Structures: Measuring Axis Extension with DIC-Based Transducers

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4104
Author(s):  
Nassr Al-Baradoni ◽  
Peter Groche
Keyword(s):  
Cost Effective ◽  
Image Correlation ◽  
Maximum Deviation ◽  
Single Image ◽  
Eccentric Load ◽  
Load Bearing ◽  
Out Of Plane ◽  
Axis Extension ◽  
Plane Displacement ◽  
Imaging Sensor

In this paper we present a novel, cost-effective camera-based multi-axis force/torque sensor concept for integration into metallic load-bearing structures. A two-part pattern consisting of a directly incident and mirrored light beam is projected onto the imaging sensor surface. This allows the capturing of 3D displacements, occurring due to structure deformation under load in a single image. The displacement of defined features in size and position can be accurately analyzed and determined through digital image correlation (DIC). Validation on a prototype shows good accuracy of the measurement and a unique identification of all in- and out-of-plane displacement components under multiaxial load. Measurements show a maximum deviation related to the maximum measured values between 2.5% and 4.8% for uniaxial loads ( and between 2.5% and 10.43% for combined bending, torsion and axial load. In the course of the investigations, the measurement inaccuracy was partly attributed to the joint used between the sensor parts and the structure as well as to eccentric load.

Using the Simplified 3D DIC Method to Measure the Deformation of 3D Surface

2011 ◽  
Vol 121-126 ◽  
pp. 3945-3949 ◽  
Author(s):  
Shih Heng Tung ◽  
Jui Chao Kuo ◽  
Ming Hsiang Shih ◽  
Wen Pei Sung
Keyword(s):  
Measurement Accuracy ◽  
Good Accuracy ◽  
Correlation Method ◽  
Image Correlation ◽  
2D Digital Image Correlation ◽  
Plate Specimen ◽  
Before And After ◽  
Out Of Plane ◽  
Plane Displacement ◽  
2D And 3D

In recent years, 2D digital image correlation method (DIC) has been widely used in the measurement of plane strain. However, out-of-plane displacement could be induced during the loading and it would affect the measurement accuracy. Thus, a 3D measurement is necessary. This study utilizes a simplified 3D DIC to measure the geometry of an object before and after deformation. Then the finite element concept is involved to determine the strain after deformation. A flat plate specimen with in-plane and out-of-plane displacement is observed. Both 2D and 3D DIC are used to analyze the strain. The results show that using 3D DIC to measure strain is feasible and with a very good accuracy.

scholarly journals The Impact Performance of Woven-Fabric Thermoplastic and Thermoset Composites Subjected to High-Velocity Soft- and Hard-Impact Loading

2019 ◽  
Vol 26 (5-6) ◽  
pp. 1389-1410 ◽  
Author(s):  
Jun Liu ◽  
Haibao Liu ◽  
Cihan Kaboglu ◽  
Xiangshao Kong ◽  
Yuzhe Ding ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Impact Loading ◽  
High Velocity ◽  
Image Correlation ◽  
Woven Fabric ◽  
High Velocity Impact ◽  
Velocity Impact ◽  
Impact Performance ◽  
The Impact ◽  
Carbon Fibre Composites

Abstract The present paper investigates the impact performance of woven-fabric carbon-fibre composites based upon both thermoplastic- and thermoset-matrix polymers under high-velocity impact loading by conducting gas-gun experiments at impact velocities of up to 100 m.s−1. The carbon-fibre reinforced-polymers (CFRPs) are impacted using soft- (i.e. gelatine) and hard- (i.e. aluminium-alloy) projectiles to simulate either a soft bird-strike or a hard foreign-body impact (e.g. runway debris), respectively, on typical composites employed in civil aircraft. The out-of-plane displacements of the impacted composite specimen are obtained by means of a three-dimensional Digital Image Correlation (DIC) system for the soft-projectile impact on the composites and the extent of damage is assessed both visually and by using portable C-scan equipment. The perforation resistance and energy absorbing capability of the composites are also studied by performing high-velocity impact experiments using the hard-projectile and the resulting extent and type of damage are identified. In addition, a Finite Element (FE) model is also developed to investigate the interaction between the projectile and the composite target.

scholarly journals Optical Evaluation on Delamination Buckling of Composite Laminate with Impact Damage

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
J. T. Ruan ◽  
F. Aymerich ◽  
J. W. Tong ◽  
Z. Y. Wang
Keyword(s):  
Composite Laminate ◽  
Impact Damage ◽  
Testing Machine ◽  
Local Deformation ◽  
Image Correlation ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Delamination Buckling ◽  
3D Deformation ◽  
The Impact

The delamination buckling and growth behaviors of a cross-ply composite laminate with damage induced by low velocity impact are investigated optically using three-dimensional digital image correlation (3D-DIC) method. For the 3D deformation measurement, the 3D-DIC setup comprised of two CCD cameras was adopted. The rectangle specimen was impacted under the impact energy of 7.0 J using a drop-weight testing machine, and the impact damage was detected by means of X-ray nondestructive evaluation (NDE) technique. The 3D deformation field measured with the optical system clearly reveals that the delamination buckling characteristic of the specimen mainly appears local deformation mode under compression after impact test. Moreover, the behavior of delamination growth evaluated by the 3D-DIC optical method reasonably agrees with the NDE observed damage result after compression.

scholarly journals The Effects of Sodium Hydroxide and Soda AQ Content on Mechanical and Physical Properties of Waste Flax Fibre Pulp Reinforced Polymer Composite Sheet

2020 ◽  
Vol 9 (2) ◽  
pp. 8-15
Author(s):  
Anupam Kumar ◽  
Ramratan . ◽  
Rohit Kumar
Keyword(s):  
Tensile Strength ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Natural Fiber ◽  
Testing Machine ◽  
Flax Fiber ◽  
Alkaline Solutions ◽  
Volume Percentage ◽  
Flax Fibres ◽  
The Impact

The aim of this study is utilized agricultural waste which may be profitable, pollution free and economically viable for the farmer and industries. In this experiment short flax fiber pulp is the natural fiber component chemically treated with alkaline solutions. Six specimens will be prepared in different volume percentage of flax fiber pulp and epoxy resin in order to get more accurate results. In this study it has been aimed to use flax fibres in composite materials and to study the mechanical properties of the produced samples. The mechanical tests results (thickness test, Tensile strength and impact strength tests) and SEM micrographs indicated flax fibres as an alternative natural fibre source for developing reinforced composites for various industries. The content of short flax fiber pulp is varied (35%, 45%, 55%) weight percentage whereas the epoxy resin is varied (50%, 40%, 30%) percentage is kept constant 15% in hardener. All the sample have been tested in universal testing machine as per ASTM standard for tensile strength and impact strength it is observed that composite with 35% flax fiber pulp is having highest tensile strength of 4 mm (4.57 Mpa) and 8 mm (6.04 Mpa). The impact strength of composite with 35% flax fiber pulp was highest than 45% to 55% flax fiber pulp.

scholarly journals Mechanical characterization and numerical modeling of TPMS lattice structures subjected to impact loading

2021 ◽  
Vol 250 ◽  
pp. 02005
Author(s):  
Rafael Santiago ◽  
Sarah Almahri ◽  
Dong-Wook Lee ◽  
Haleimah Alabdouli ◽  
Omar Banabila ◽  
...  
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
High Energy ◽  
Image Correlation ◽  
Dynamic Strain ◽  
Correlation Technique ◽  
Fe Model ◽  
Strain Rates ◽  
The Impact ◽  
Constitutive Parameters

The advent of Powder Bed Fusion (PBF) techniques allows the additive manufacturing of complex structures, as Triply Periodic Minimal Surfaces (TPMS) lattices, which exhibit promising characteristics for impact applications, such as lightweight and high-energy absorption. Thus, this work aims to develop a numerical model of TPMS structures to investigate the mechanical response of such structures when subjected to impact loadings. To fulfill this task, stainless steel samples made by PBF technique were mechanically characterized at different strain rates using a universal testing machine and Split Hopkinson Pressure Bar. The testing campaign also explored the compressive and tensile material response, with the strain field being monitored by Digital Image Correlation technique. It was noted that the material exhibits a similar elasto-plastic response on both tension and compression and an evident strain rate hardening when the material is loaded from static (0.001 s-1) to dynamic strain rates (4000 s-1). Constitutive parameters were then obtained and implemented in an explicit finite element model developed through Abaqus CAE. Samples of TMPS lattices were manufactured and tested at different loading velocities, which showed that the FE model developed can be used to predict the impact response of TMPS lattices.

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