Fiber Reinforced Plastic Composites Research Articles

Biomimetic approaches towards lightweight composite structures for car interior parts

Due to good density specific mechanical properties and low carbon footprint, natural fibre-reinforced plastic composites made from fleeces and felts are frequently used as automotive interior parts. The industry targets further mass reduction. Following a biomimetic technology-pull approach, natural fibre-reinforced polypropylene plates with improved lightweight potential were produced using compression moulding. Best results were obtained for a sandwich structure with thin, unidirectional flax fibre layers surrounding a needle felt based core. It was inspired by the carapace structure of the red-eared slider Trachemys scripta elegans. The lay-up performed well, not only with a high density specific flexural stiffness of 2.33GPa1/3 cm3/g, strength of 9.46 MPa1/2 cm3/g, and energy dissipation but also through less abrupt failure due to an asymmetric orientation of unidirectional fibres in the two face sheets. Combined with a mass-reduced needle felt as a core, this concept displays a promising and unconventional approach for further mass reduced, sustainable interior panels used as non-visible and visible design elements in the vehicle.

Thermal barrier coating for carbon fiber-reinforced composite materials

Carbon fiber-reinforced plastic (CFRP) composites are widely employed in lightweight and high performance applications including supercars, aero-vehicles, and space components. However, although carbon fibers are thermally stable, the low thermal endurance of the matrix materials remains a critical problem in terms of the performance of the material. In this study, we proposed a new, Al 2 O 3 -based thermal barrier coating (TBC) for the CFRP composites. The TBC comprised α-phase Al 2 O 3 particles with a mean diameter of 9.27 μm. The strong adhesion between the TBC and the CFRP substrate was evaluated using a three-point bending test. When the CFRP substrate was subjected to a 500–700 °C flame, the 1.45-mm thick TBC protected the CFRP substrate remarkably by reducing the surface temperature to 188–228 °C. The thermo-mechanical responses of this TBC/CFRP composite were analyzed after thermal shock tests. Surprisingly, 50% of the pristine flexural strength of the TBC/CFRP composite was preserved, whereas that of neat CFRP was reduced significantly by 95%.

Lamb wave-based damage detection of composite structures using deep convolutional neural network and continuous wavelet transform

Carbon fiber reinforced plastics composites have been widely used in aerospace, automotive and other fields for its superior performance. To avoid possible risks, Lamb waves-based structural heath monitoring techniques have been applied to detect the internal damage of these composites. However, due to their intrinsic high degree of anisotropy which makes the failure mode complicated under fatigue loads, an accurate and timely method for damage detection of these composites is still challenging to realize. This paper proposes a novel method for detecting the internal delamination of the carbon fiber reinforced plastics by combining deep convolutional neural network and continuous wavelet transform. This data-driven method can effectively leverage the large amount of data without relying on complex feature extraction. After converting the time series signal into a two-dimensional time–frequency image by the continuous wavelet transform technique, the convolutional neural network model is applied to classify the images. Based on the prediction results of different paths by the model, a damage localization method is also proposed for ply delamination. An experimental study is implemented to verify the effectiveness of this method. The result shows this method is a useful technique for precise diagnosis and positioning of delamination damage in the composite structures.

Optimization of a Totally Fiber-Reinforced Plastic Composite Sandwich Construction of Helicopter Floor for Weight Saving, Fuel Saving and Higher Safety

The application of fiber-reinforced plastic (FRP) composites as structural elements of air vehicles provides weight saving, which results in a reduction in fuel consumption, fuel cost, and air pollution, and a higher speed. The goal of this research was to elaborate a new optimization method for a totally FRP composite construction for helicopter floors. During the optimization, 46 different layer combinations of 4 different FRP layers (woven glass fibers with phenolic resin; woven glass fibers with epoxy resin; woven carbon fibers with epoxy resin; hybrid composite) and FRP honeycomb core structural elements were investigated. The face sheets were composed of a different number of layers with cross-ply, angle-ply, and multidirectional fiber orientations. During the optimization, nine design constraints were considered: deflection; face sheet stress (bending load, end loading); stiffness; buckling; core shear stress; skin wrinkling; intracell buckling; and shear crimping. The single-objective weight optimization was solved by applying the Interior Point Algorithm of the Matlab software, the Generalized Reduced Gradient (GRG) Nonlinear Algorithm of the Excel Solver software, and the Laminator software. The Digimat-HC software solved the numerical models for the optimum sandwich plates of helicopter floors. The main contribution is developing a new method for optimizing a totally FRP composite sandwich structure—due to its material constituents and construction—that is more advantageous than traditional helicopter floors. A case study validated this fact.

Self-Healing Structural Materials.

Self-healing materials have been developed since the 1990s and are currently used in various applications. Their performance in extreme environments and their mechanical properties have become a topic of research interest. Herein, we discuss cutting-edge self-healing technologies for hard materials and their expected healing processes. The progress that has been made, including advances in and applications of novel self-healing fiber-reinforced plastic composites, concrete, and metal materials is summarized. This perspective focuses on research at the frontier of self-healing structural materials.

Bioactive Glass Fiber-Reinforced Plastic Composites Prompt a Crystallographic Lophelia Atoll-Like Skeletal Microarchitecture Actuating Periosteal Cambium.

The touchstone for bone replacing or anchoring trauma implants, besides resorption, includes functional ankylosis at a fixation point and replacement by viable functional neo-bone tissues. These parameters redefined the concept of "resorbability" as "bioresorbability." Interference screws are the most commonly used resorbable anchoring implants for anterior cruciate ligament (ACL) reconstruction (surgery). Over the years, the bioresorbable screw fixation armamentarium has amplified countless choices, but instability and postimplantation complications have raised concerns about its reliability and efficacy. Owing to this interest, in this work, bioactive glass fiber-reinforced plastic (BGFP) composites with (BGFPnb5) and without (BGFP5) niobicoxide composing multiplexed network modifiers are reported as bioresorbable bone-anchoring substitutes. These synergistically designed composites have a fabricated structure of continuous, unidirectional BG fibers reinforced in an epoxy resin matrix using "melt-drawing and microfabrication" technology. The BGFP microarchitecture is comprised of multiplexed oxide components that influence bioactive response in a distinctive lophelia atoll-like apatite formation. Furthermore, it assists in the proliferation, adherence, and migration of bone marrow-derived mesenchymal stem cells. It also exhibits superior physicochemical characteristics such as surface roughness, hydrophilic exposure, distinctive flexural strength, and bioresorption. Thus, it induces restorative bone osseointegration and osteoconduction and actuates periosteum function. In addition, the BGFP influences the reduction of DH5-α Escherichia coli in suspension culture, demonstrating potential antibacterial efficacy. In conclusion, the BGFP composite therapeutic efficacy demonstrates distinctive material characteristics aiding in bone regeneration and restoration that could serve as a pioneer in orthopedic regenerative medicine.

High-frequency vibration effects on the hole integrity in rotary ultrasonic drilling of carbon fiber-reinforced plastic composites

This investigation represented a fundamental research on the potential effects of the high-frequency vibration on the hole integrity involved in rotary ultrasonic drilling (RUD) of carbon fiber-reinforced plastic (CFRP) composites. It was found the increased thickness of the CFRP plate shrunk the flowing velocity of the coolant, which brought about the residual chippings gradually accumulated at the radial clearance between the tool and the material. Furthermore, the chipping accumulation at the clearance seriously increased the friction effects and the resultant thermal load, thus leading to the chipping adhesions on the tool surface and machined cylinder jamming at the central hole of the tool. The mutual constrain between two vertical bundles brought the delamination around the holes generated in conventional drilling (CD) process to a termination at the bundle interface. The ultrasonic superimposition reduced the thrust force of the diamond tool which provided inadequate energy for the delaminated fibers reaching the bundle interface. Moreover, hole position on the two-dimensional orthogonal fabrics significantly influenced the propagation of the delaminated fibers, which weakened the effects of the drilling parameters on the delamination dimensions. Additionally, superimposing an ultrasonic vibration prolonged the abrasive trajectories and increased their overlapping probability, and the induced smoothing effects resulted in the obvious reduction of the surface roughness. The tensile stress exerted on the margin of the machined surface was responsible for the initiation of the CD delamination. After the delaminated fibers reached the bundle interface, the further extrusion of tool brought about the margin suffered from the shear stress, thus leading to the collapse of the machined cylinder. Considering the thrust force of the diamond tool and the undrilled thickness of the machined surface, the critical conditions of the delamination initiation were developed, which revealing that the decreasing of the thrust force caused the reduction of the critical undrilled thickness.

A micromechanical model of carbon fiber-reinforced plastic and steel hybrid laminate composites

The fracture strain of carbon fiber-reinforced plastics (CFRPs) within CFRP/steel hybrid laminate composites is reportedly higher than that of CFRPs due to transverse compressive stress induced by the steel lamina. A micromechanical model was developed to explain this phenomenon and also to predict the mechanical behavior of CFRP/steel hybrid laminate composites. First, the shear lag theory was extended to calculate stress distributions on fibers and matrix material in a CFRP under multiaxial stress condition, considering three deformation states of matrix (elastic and plastic deformation and fracture) and the transverse compressive stress. Then, the deformation behavior of CFRP was predicted using average stress in the ineffective region and the Weibull distribution of carbon fibers. Finally, the mechanical properties of CFRP/steel hybrid laminate composites were predicted by considering the thermal residual stress generated during the manufacturing process. The micromechanical model revealed that increased transverse compressive stress decreases the ineffective lengths of partially broken fibers in the CFRP and results in increased fracture strain of the CFRP, demonstrating the validity of the current micromechanical model.

Ultrasonic machining of carbon fiber–reinforced plastic composites: a review

Carbon fiber–reinforced plastic (CFRP) composites are extensively being applied in manufacturing sectors because of their extraordinary characteristics. However, CFRP composites often require some extra machining processes to improve the dimensional accuracy and component integrity of CFRP composites in manufacturing industries. The ultrasonic machining (USM) process progressively has been examined due to its greater ability in machining difficult to cut, brittle, and hard materials such as CFRP composites and due to its relatively low machining cost. Furthermore, USM shows to be a promising process with better surface quality, lower cutting force, less or no fiber fracture, laminate delamination, and lower tool wear rate. Recently, USM has been extensively investigated by many researchers for the machining of CFRP composites. This paper explores the literature and presents a comprehensive review of the advances in USM of CFRP composites by classifying the studies reported in two perspectives. First, the review summarizes most of the reported studies starting from 2011 to 2020 based on the applied USM process, equipment/system/platform used to carry out experiments, considered process parameters and output variables, and challenges investigated or gap filled. Then, the reported studies are summarized considering the type of USM process variant, CFRP composite, adopted process parameters on machining characteristics, and their respective results and conclusions. The aim is to present the current research status in USM of CFRP composites and thus provide guidance and foundation for future research.

Optimization of Cutting Tool Geometry for Milling Operation using Composite Material – A Review

Fibre reinforced composite materials having their own specific advantages are why they currently gain more and more attention. A vital procedure once preparations of materials are done is the machining process. Various secondary operations such as milling, drilling, turning and various unconventional processes are used for achieving near net shape and size of desired component. Compared to conventional materials, fibre reinforced composite materials are more practical to be use in machining process due to less amount of cutting forces are required to complete the exact shape and size of desired component. Therefore, a review on milling of fibre reinforced composite material will be helpful for numerous researchers and other manufacturing industries, which are currently working in this field. This review paper represents the classification of composite materials, Fiber Reinforced Plastic (FRP) Composites and Carbon Fibre Reinforced Plastic (CFRP) Composites. In addition, this review also defines the machinability of CFRP composites selection and tool design of end mill.

Numerical and experimental investigation of the delamination in drilling of the carbon fiber-reinforced plastic composite

During the drilling of the carbon fiber-reinforced plastic composite, delamination causes undesirable defects that degrade the quality of products. Thus, the backup plate has been adapted to the composite drilling to prevent delamination. In this study, we present a method to predict the delamination factor of composite laminate according to the cutting conditions as well as the backup plate condition using FE model. We analyzed the damage generated at the exit surface of the composite laminate, using cohesive zone model with user-defined material model of the Abaqus/Explicit software. Damage behavior was simply simulated and quantified to the delamination factor using the parameter criterion CSDMG. Furthermore, appropriate CSDMG variables were selected to predict the accurate delamination factors considering the backup plate condition. Based on the experiment, the delamination factor was calculated with the computed tomography images of the drilled workpiece to quantify the damage. Delamination factors of prediction results and experimental data were performed. It was observed that the maximum error was 10.1% and 19.6% with and without backup plate condition respectively.

Progressive damage characterization of biaxial carbon fiber Reinforced epoxy composites

The objective of the work was to investigate bi-axial characteristics of composite materials with cruciform geometry in both experimental and numerical techniques. The carbon reinforced fibers with epoxy composites prepared by hand lay-up technique with various stacking sequences such as 0°/90°, 45°/45°, 15°/75° and 30°/60°. The fabricated composites were machined in cruciform shape, having different notches namely circular, square and rhomboidal according to ASTM – D6856 standard by abrasive water jet machining to ensure dimensional accuracy of ± 0.1 mm. The prepared cruciform specimens were tested using a biaxial fixture developed indigenously by taking the specifications of universal testing machine. The Young’s modulus, proof stress, ultimate tensile strength and fracture toughness were evaluated for 16 specimens of different fibre orientations and notches using software. The response from the biaxial tensile test showed highest stress developing in [0°/90°] Carbon Fibre Reinforced Plastic (CFRP) composites of 61.37 MPa with highest ultimate tensile strength of 71.93 MPa experimentally. Numerical simulation with ANSYS was showing maximum stresses developing in [0°/90°] Carbon Fibre Reinforced Plastic (CFRP) composites 65.37 MPa.

Investigations on tool clogging and surface integrity in ultrasonic vibration-assisted slot grinding of unidirectional CFRP

Carbon fibre-reinforced plastic (CFRP) composites have been widely used in the field of aerospace and transportation because of their excellent mechanical properties. However, excessive tool clogging commonly occurs because of low chip storage space, thereby leading to workpiece failure. The slot grinding experiments with and without ultrasonic vibration were performed by using abrasive tools with defined grain pattern to improve tool life. The mathematical model of the fibre cutting angle in ultrasonic vibration-assisted slot grinding (USG) was established. The influences of ultrasonic vibration on the grinding force, tool clogging and surface integrity of unidirectional CFPR were discussed quantitatively. Results show that the USG featured lower grinding force, shorter fibre chip and better surface integrity than the conventional slot grinding (CSG). In addition, the lowest and highest reduction rates of grinding forces are obtained by using the fibre orientation of 90° and 135°, respectively. The maximum fibre chip lengths produced in USG are approximately 78% and 66% lower than those in CSG with fibre orientations of 0° and 90°, respectively. Several adhesive chips are observed on the USG tool surface. The chip storage spaces in CSG are filled with adhesive chips. The USG has a positive influence on surface roughness and damage because of the changes in fibre cutting angle. Compared with CSG, the USG produces similar fibre fracture patterns, except at the fibre orientation of 0°. Furthermore, the surface defects in USG are lower than those in CSG.

Effect of Production Variables on the Physico-Mechanical Properties of Fibre-Reinforced Plastic Composites Boards Produced from Waste Paper and Re-Cycled Polyethlene

The mechanical and physical properties of fibre reinforced composite boards (FRCB) made from waste paper and recycled polyethylene was investigated. The composite boards were produced at three levels of mixing ratio (50:50, 60:40 and 70:30) and three levels of board density (1000 Kg/m³, 1100 Kg/m³ and 1200 Kg/m³). The fibre from the paper served as the reinforcement while the polyethylene served as the matrix or binder to form the composite board. The board produced was subjected to different standard tests to attain mechanical and physical properties such as modulus of rupture (MOR), modulus of elasticity (MOE), water absorption (WA) and thickness swelling (TS). The mean values obtained for Thickness Swelling after 24 hours and 48 hours ranged from 0.02 ± 0.04 to 6.05 ± 3.21 and 3.06 ±1.27 to 12.59 ±0.05 respectively and that of water absorption after 24 hours and 48 hours ranged from 4.68 ± 0.25 to 15.78 ± 6.15 and 5.36 ± 0.16 to 18.37 ± 6.03 respectively. The mean value for MOR and MOE ranged from 16.36 ± 9.71 to 18.17 ± 6.76 and 3813.4 ± 1938.76 to 4842.8 ± 1381.05 respectively. These results shown that both the WA and TS decreased with the increase in the board density and mixing ratio. On the other hand, MOR and MOE of the board increased with the increase of board density and the mixing ratio. The results obtained from this study shown that natural fibre from waste paper and recycled polyethylene are compatible for use to produce composite material.

Coupling inverse fin method with infrared thermography to determine the effective thermal conductivity of extruded thermoplastic foams

An inverse method for determining the in-plane effective thermal conductivity of porous thermoplastics was implemented by coupling infrared thermography experiments and numerical simulation of heat transfer in straight fins having temperature-dependent convective heat transfer coefficient. The microstructure heterogeneity of extruded polyethylene foam, in which pores are filled with air with different levels of open and closed porosity, was taken into account. The obtained effective thermal conductivity values were compared with previous results obtained using a numerical solution based on periodic homogenization techniques (NSHT) and the transient plane source technique (TPS) to verify the accuracy of the proposed method. The results show that the suggested method is in good agreement with both NSHT and TPS. Moreover, it is also appropriate for structural materials such as unidirectional fiber-reinforced plastic composites, where heat transfer is very different according to the fiber direction (parallel or transverse to the fibers).

Relationship Between Functionalized Multi-Walled Carbon Nanotubes and Damping Properties of Multi-Walled Carbon Nanotubes/Carbon Fiber-Reinforced Plastic Composites for Shaft.

The mechanical properties and damping behavior of carbon fiber-reinforced plastic composites with functionalized multi-walled carbon nanotubes were examined. The functionalized multi-walled carbon nanotubes were blended with epoxy resins to prepare multi-walled carbon nanotubes/carbon fiber-reinforced plastic composites. The dispersion properties of functionalized multi-walled carbon nanotubes in epoxy resins were examined using surface free energy. The mechanical properties of functionalized multi-walled carbon nanotubes/carbon fiber-reinforced plastic composites were measured by interlaminar shear strength and torsion strength. The functionalized multi-walled carbon nanotubes/carbon fiber-reinforced plastic composites had superior mechanical properties due to the increase in dispersion properties of functionalized multi-walled carbon nanotubes in epoxy resins. However, the tan delta values of damping behavior, analyzed by dynamic mechanical analysis, varied with the type of functional groups of functionalized multi-walled carbon nanotubes. The composites obtained from functionalized multi-walled carbon nanotubes obtained through spermidine amidation reaction and carbon fiber-reinforced plastic showed excellent tan delta values due to the flexible segments in side chains.

WITHDRAWN: Effects of hybridization on the mechanical properties of hybrid composite laminates – A review

Abstract Rising environmental anxiety has lifted the research and industrial attention towards the growth of natural and synthetic fiber for various industrial applications. Research is going on to develop newer fiber-reinforced plastic composites in order to replace metals and alloys. In this review paper, we are going to discuss about various recent work or review report on fibers used as an alternative for existing and developing products for the purpose of manufacturing cost effective composite materials. The paper also concentrates on the effect of hybridization on the various mechanical properties of a hybrid composite for the purpose of designing, analyzing and fabricating an aircraft’s wing structure. The proposed structure is made of composites consisting of carbon/aramid/glass/basalt fibers. The component is to be modeled and analyzed by the use of finite element method by ANSYS software for finding out the deflections and stresses induced in the composite. The purpose of this paper is to get a better understanding of the mechanical response of various hybrid composites. The mechanical testing for the fiber composite is to be carried out according to respective ASTM standards for better understanding of their properties.

Adiabatic heating and damage onset in a pultruded glass fiber reinforced composite under compressive loading at different strain rates.

Damage onset and adiabatic heating of a pultruded Glass Fiber-Reinforced Plastic (GFRP) composite was investigated using compression tests at low, intermediate and high strain rates (10−3 s−1, 1 s−1 and 103 s−1). Optical and infrared (IR) cameras monitored the specimens during testing, so that the mechanical response, damage onset, and damage evolution were obtained along with the adiabatic heating of the specimen due to plastic deformation and fracture. The results revealed clear strain rate effects on stiffness, strain softening and damage initiation. The simultaneous optical and IR imaging allowed quantitative description of thermomechanical response of the material and studying the formation and propagation of shear localizations and their temperature history. The maximum temperatures in the fracture zones exceed 80 °C at the strain rate of 103 s−1. Scanning Electron Microscopy (SEM) was used to identify the micro-scale crack paths at different strain rates. The findings allow more exact numerical predictions and design of tubular GFRP pipes for impact applications.

Vibration analysis of interply hybrid composite for an aircraft wing structure

Due to the rise in environmental issues the research and development of natural and synthetic fibers have risen exponentially for various industrial applications. Research is going on to develop newer fiber-reinforced plastic composites in order to replace metals and alloys. Due to the flexibility composite materials offer compared to metals there has been many innovations coming up in the aerospace industry. Composite materials due to their most desirable property, the high strength to weight ratio have play a major role in weight reduction, and they used for both structural applications and components of all automobiles and space crafts. With primary focus of aerospace industry being to reduce weight and thereby reducing fuel consumptions. The objective of this project is to design and fabricate a simple airfoil wing skin using hybrid composites and to experimentally study its vibrational behavior. The primary focus of this project is to understand the effect of hybridization on the mechanical properties namely vibrational behavior of composite structures. The composites used are carbon, aramid, basalt and glass fibers. The specimens were fabricated by the simple and most common hand lay-up method. The hybrid configurations fabricated were CGC (carbon/glass/carbon), AGA (aramid/glass/aramid) & BGB (basalt/glass/basalt). Free vibration tests were performed to study their natural frequencies and also to understand their damping characteristics.

A study on the machinability of advanced arc PVD AlCrN-coated tungsten carbide tools in drilling of CFRP/titanium alloy stacks

This study aims to investigate the effect of an aluminum chromium nitride (AlCrN) coating on tool wear and hole quality in the conventional drilling process of carbon fiber-reinforced plastic (CFRP) composites, titanium alloy (Ti), and CFRP–Ti stack workpieces popular in the aerospace industry. The advanced arc plasma acceleration (APA) method of physical vapor deposition (PVD) was used for all AlCrN coatings. The drilling experiments were conducted with uncoated drills as well as AlCrN-coated drills. When drilling CFRP only, the AlCrN coating was removed at the drill cutting edges and the margin area, which suggests the carbon fibers abraded the coatings. When drilling Ti only, the AlCrN-coated drill mitigated the Ti adhesion formation, which resulted in less tool wear. In addition, hole quality for both CFRP and Ti was improved when the coating was used versus the uncoated tool. The machinability of CFRP–Ti stacks in the drilling process was improved by utilizing the advanced AlCrN coating on the WC tool in terms of drilling forces and hole quality parameters such as average hole size, average hole roundness, hole surface roughness, and Ti exit burr height.