Fiber Stacking Research Articles

Postbuckling response of functionally graded hybrid plates with cutouts under in-plane shear load

The present study deals with the investigation of buckling and postbuckling responses of functionally graded hybrid square plates which are symmetric about its mid plane. The cutouts of various sizes and shapes located at the center of the plate are considered. The plate is subjected to positive and negative in-plane shear loads. The boundary conditions used are simply supported on all the four edges of the plate. Three stacking sequences are considered to investigate the optimum stacking sequence at which the critical buckling and first failure loads are highest. Functionally graded hybrid plates (FH) subjected to negative in-plane shear load is more effective compared to plates subjected to positive in-plane shear load. Diamond shaped cutout with small sized perforation has the highest critical buckling and first ply failure loads amongst the FH plates with cutouts. It is observed that the direction of applied in-plane shear load, fiber stacking sequence; cutout shape and size substantially influence the strength and failure characteristics of functionally graded hybrid composite plates.

Application of Laser-Ultrasonic Technique of Acoustic Impedance Measurement with Signals Detection by Backward-Mode Scheme for Porosity Content Evaluation in CFRP Laminates

The aim of this work is the development and experimental implementation of the laser-ultrasonic method for CFRPs porosity assessment with one-side access to an investigated object. The scheme with the laser thermooptical generation and backward-mode piezoelectric detection of longitudinal acoustic waves is used. The proposed method is based on the measurement of the acoustic impedance of a composite specimen by using the value of the integral of the ultrasonic pulse reflected from an immersion layer-specimen interface. The existence of the relationship between the porosity content, ultrasound velocity, and material’s density allows one to assess the porosity of CFRPs by the measured acoustic impedance. The proposed method does not require plane parallelism of the input and output surfaces of the studied objects, as well as measuring the thickness of the object. This allows studying CFRP structures with complex shapes. This method may be of use for various types of composite materials, regardless of acoustical waves propagating features related to a periodical material’s structure. CFRP specimens with three reinforcement schemes and different average volume porosity contents were investigated. It is shown that the local porosity distribution in the studied CFRPs is nonuniform along the fiber stacking plane. The porosity content obtained by the laser-ultrasonic method was checked using the X-ray computer tomography. The porosity values, averaged from the laser-ultrasonic measurement results, coincide with the X-ray tomography data within the error limits. The method can be useful for quality control of obtained composite structures with the aim of modernization of technology processes and selecting optimal production conditions and also for the detection of changes in composite structures during their operation or during fatigue testing processes.

The Influence of Fiber Orientation and Stacking Sequence on the Crush Behavior of Hybrid AL/GFRP Tubes under Axial Impact

The Influence of Fiber Orientation and Stacking Sequence on the Crush Behavior of Hybrid AL/GFRP Tubes under Axial Impact

Broad Bandwidth, Self-Powered Acoustic Sensor Created by Dynamic Near-Field Electrospinning of Suspended, Transparent Piezoelectric Nanofiber Mesh.

Freely suspended nanofibers, such as spider silk, harnessing their small diameter (sub-micrometer) and spanning fiber morphology, behave as a nonresonating acoustic sensor. The associated sensing characteristics, departing from conventional resonant acoustic sensors, could be of tremendous interest for the development of high sensitivity, broadband audible sensors for applications in environmental monitoring, biomedical diagnostics, and internet-of-things. Herein, a low packing density, freely suspended nanofiber mesh with a piezoelectric active polymer is fabricated, demonstrating a self-powered acoustic sensing platform with broad sensitivity bandwidth covering 200-5000 Hz at hearing-safe sound pressure levels. Dynamic near-field electrospinning is developed to fabricate in situ poled poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) nanofiber mesh (average fiber diameter ≈307 nm), exhibiting visible light transparency greater than 97%. With the ability to span the nanomesh across a suspension distance of 3 mm with minimized fiber stacking (≈18% fiber packing density), individual nanofibers can freely imitate the acoustic-driven fluctuation of airflow in a collective manner, where piezoelectricity is harvested at two-terminal electrodes for direct signal collection. Applications of the nanofiber mesh in music recording with good signal fidelity are demonstrated.

Role of Surface Functionalized Crystalline Nano-silica on Mechanical, Fatigue and Drop Load Impact Damage Behaviour of Effective Stacking Sequenced E-glass Fibre-reinforced Epoxy Resin Composite

This present investigation deals the role of surface functionalized crystalline nano-silica addition into epoxy resin on fatigue, fracture toughness and drop load impact damage behaviour with various stacking sequence of E-glass fibre. The main objective of this current investigation was revealing the importance of surface-functionalized crystalline nano-silica particle in E-glass fibre reinforced epoxy composite. Crystalline nano-silica of 20nm and E-glass fibre of 600 GSM was used as reinforcements. Both the particles and fibre was surface-functionalized using 3-Aminopropyletrimethoxyle (APTMS) via wet solution method. The hybrid composites were prepared via hand layup technique with different fibre stacking sequence. The mechanical results revealed that fibre pattern of L-A-L with 1.0vol.% of nano-silica gave highest tensile and flexural strength. The fatigue results revealed that the addition of 0.5 vol.% crystalline nano-silica into glass-epoxy composite (ES1) gives highest fatigue life cycle of 38544 in 50% of tensile stress. Similarly, the fracture toughness results revealed that a highest fracture toughness of 31.5 MPa was observed for composite designation ES2. The composite, which contains 1.0vol.% of surface functionalized crystalline nano-silica with L-A-L fibre pattern gives very high drop load impact resistance. Thus for high strength structural applications, automobile, aircraft and sports related applications these composites could be more suitable and replaced.

Mechanical Conduct on Banana Fiber Fortified Polymer Composite with the Effect of Fiber Stacking and Length of Fiber on the Properties of Composites

In view of the growing normal concerns, bio composite delivered out of customary fiber and polymeric tar, is one of the late headways in the business and comprises the present degree of experimental work. The utilization of composite materials field is expanding bit by bit in designing. The composite comprises of fundamentally two stages for example grid and fiber. The availability of trademark fiber and effortlessness of amassing have allured researchers worldwide to endeavour by local benchmarks open cheap fiber and to learning their reachability of fortress judgments and to what degree they satisfy the obliged specifics of extraordinary fortified polymer composite went for basic order. Fiber fortified polymer composites has various inclinations, for instance, by and large negligible exertion of creation, easy to create and preferred quality difference over immaculate polymer tars due with this reason fiber reinforced polymer composite used inside a combination of arrangement as class of structure material. This work depict the mechanical conduct of banana fiber fortified polymer composite with the remarkable references to the effect of fiber stacking and length of fiber on the properties of composites.

Effect of Glass Fiber Stacking Sequence on the Notch Sensitivity of Glass Fiber Reinforced Epoxy Matrix Composites

This research article investigated the effect of stacking sequence of glass fibers on the notched and unnotched tensile strength of glass fibers plies reinforced epoxy matrix composites fabricated by the hand lay-up technique. The orientation of glass fabrics was kept at [(0/90)]5, [(45/-45)]5 and [(0/90), (45/-45), ]s and all the laminates were prepared using five plies for different stacking sequences with fiber volume content of 38.6 vol.% with different ratios of the specimen hole diameter to the specimen width with three different values (0.1, 0.2, 0.5). The notch sensitivity of these composites was evaluated applying Whitney-Nuismer mathematical model. The results indicated that the composites with [(0/90)]5 stacking sequence displays the highest tensile unnotched strength, whereas the composites with [±45°]5 stacking sequence displays the least strength. Moreover, the notch sensitivity of [±45°]5 composites is almost higher than those of other stacking sequences with different D/W ratios. On the other hand, the notch sensitivity of [(0/90), (45/-45), ]s composites is slightly lower than those of [(0/90)]5 composite structures for different D/W ratios. Moreover, SEM micrographs indicates the most common failure modes for [(0/90), (45/-45), ]s and [(45/-45)]5 are more significant delamination and matrix cracking than that of [(0, 90)]5.

A cuckoo search based neural network to predict fatigue life in rotor blade composites

In modern wind turbine blades industry, fiber-reinforced composites are mostly used for their good mechanical characteristics: high stiffness, low density and long fatigue life. Wind turbine blades are constructed in different structural elements from a variety of composite laminates, often including Unidirectional (UD) material in spars and multiple forms of Multidirectional (MD) in skins and webs. The purpose of this paper is to identify materials that have appropriate fiber orientations to improve fatigue life. By using Cuckoo Search-based Neural Network (CSNN), we have developed a model to predict fatigue life under tension-tension charges for five composite materials, with different fiber stacking sequences embedded in three types of resin matrices (epoxy, polyester and vinylester), which are all appropriate for the design of wind turbine blades. In the CSNN approach used in this work, the cost function was assessed using the Mean Square Error (MSE) computed as the squared difference between the predicted values and the target values for a number of training set samples, obtained from an experimental fatigue database. The results illustrate that the CSNN can provide accurate fatigue life prediction for different MD/UD composite laminates, under different angles of fiber orientation.

Design of a 70 MPa type IV hydrogen storage vessel using accurate modeling techniques for dome thickness prediction

The aim of this study is to propose methods for dome thickness distribution and the charge pressure of the liner for a 70 MPa type IV hydrogen storage vessel. The netting theory was employed to design the lay-up of the cylindrical section. For precise prediction of the dome thickness, a cubic spline function was utilized. Variable polar radii were used to reduce the fiber stacking and thickness accumulation near polar openings. To evaluate the designed lay-up, various failure criteria were applied so as to predict precisely the failure of composite layers in finite element analysis. In order to determine the most appropriate range of the internal pressure when filling hydrogen gas during filament winding process, the compressive pressure applied on the liner was calculated by taking into account the variety of winding tension, and the buckling and static analysis of the liner were carried out, respectively. The methods presented in this work provide a valuable reference for designing the type IV hydrogen storage vessels.

Laser Optoacoustic Method for Quantitative Porosity Assessment of Carbon Fiber Reinforced Plastic Composites Based on Acoustic Impedance Measurement

Abstract—A method for measuring the acoustic impedance for the assessment of the porosity of carbon fiber reinforced plastic composites using laser thermo-optical excitation of longitudinal acoustic waves is proposed and experimentally realized. The acoustic impedance of the test sample is measured from the magnitude of the antiderivative ultrasonic pulse reflected from the immersion liquid–sample interface. A method for calculating the porosity of carbon fiber plastic composites based on the measured acoustic impedance is presented. Composite samples with three different carbon fiber layers stacking schemes were investigated. It is shown that in the studied composites, the local porosity distribution is nonuniform along the fiber stacking plane. The porosity value, averaged from optoacoustic measurement results, actually coincides with X-ray tomography data within the error limits. The presented method for determining porosity does not require determining the volume and mass of the studied object and can be used for investigation of composite structures with complex shapes.

Effect of Stacking Sequence and Fiber Orientation on Natural Frequency of Hybrid Composites – an FE Approach

Hybridization technique wherein more than one type of fiber is combined in the same matrix provides an added advantage to the designer to further explore the potential of fiber-reinforced polymer composite. The dynamic behavior of an interlayer hybrid composite is complex as the stiffness of each layer of the fiber can influence the modal parameters like frequency and mode shapes. In this work the dynamic behavior of the interlayer hybrid composites is investigated. The Eigen values and Eigen vectors for glass & carbon fiber reinforced hybrid polymer composites are numerically obtained using the Finite Element software (ANSYS). The effects of fiber direction and inter layer fiber stacking sequence on the Eigen values and Eigen vectors are studied. The variation of natural frequencies for boundary conditions such as Free-Free-Free-Free (F-F-F-F) & Clamped-Free-Free-Free (C-F-F-F) are also presented in this paper.

Influence of glass/carbon fiber stacking sequence on mechanical and three-body abrasive wear resistance of hybrid composites

Glass and carbon fiber reinforced polymer hybrid composites are the need of the hour to overcome the weakness of individual fibers. The mechanical and abrasive wear property of the hybrid composites needs to be evaluated to ascertain the feasibility in structural and tribological applications. In this article, hybrid composites of different stacking sequence such as [G3C2]S, [GCG2C]S and[G2C2G]S has been designed. The flexural strength and three body abrasive wear resistance of the hybrid composites were evaluated and compared among themselves. It is observed that the flexural strength and modulus of [GCG2C]S type hybrid composite was improved by 46.1% and 49.5% respectively as compared to plain glass fiber reinforced polymer composites. The specific wear rate was evaluated by three-body abrasive wear at different operating parameters and optimized the same through response surface methodology. Box–Behnken design of the experiment was adopted to design the experiments. The model has predicted the minimum specific wear rate for [GCG2C]S hybrid composite is18.8476 × 10–3 mm3 Nm−1 at applied load of 33.15 N and sliding distance of 1100 m. The model predicted results were compared with experimental one and found a good agreement between them. The worn surface of the composites was analyzed by scanning electron microscope to understand the wear mechanism.

Glass Fiber Hybrid and Stacking Sequence Effects on the Properties of Sisal/Polyester Composite

The need for biodegradable materials is the motivation behind studying the hybridization effect of natural and synthetic fiber composite. In this study six different compositions of sisal and glass are studied. Mechanical properties viz. tensile and bending are evaluated and compared for different compositions. Glass used at core showed slightly higher tensile strength than at skin. Also, it is found that the flexural strength is highest for 4 sisal layers at core and glass at skin. Fatigue life evaluation of all glass and all sisal composition is also performed which shows better fatigue performance of all glass composition.

Characterization of Polydioxanone in Near-Field Electrospinning.

Electrospinning is a popular method for creating random, non-woven fibrous templates for biomedical applications, and a subtype technique termed near-field electrospinning (NFES) was devised by reducing the air gap distance to millimeters. This decreased working distance paired with precise translational motion between the fiber source and collector allows for the direct writing of fibers. We demonstrate a near-field electrospinning device designed from a MakerFarm Prusa i3v three-dimensional (3D) printer to write polydioxanone (PDO) microfibers. PDO fiber diameters were characterized over the processing parameters: Air gap, polymer concentration, translational velocity, needle gauge, and applied voltage. Fiber crystallinity and individual fiber uniformity were evaluated for the polymer concentration and translational fiber deposition velocity. Fiber stacking was evaluated for the creation of 3D templates to guide the alignment of human gingival fibroblasts. The fiber diameters correlated positively with polymer concentration, applied voltage, and needle gauge; and inversely correlated with translational velocity and air gap distance. Individual fiber diameter variability decreases, and crystallinity increases with increasing translational fiber deposition velocity. These data resulted in the creation of tailored PDO 3D templates, which guided the alignment of primary human fibroblast cells. Together, these results suggest that NFES of PDO can be scaled to create precise geometries with tailored fiber diameters for biomedical applications.

The crashworthiness performance of stacking sequence on filament wound hybrid composite energy absorption tube subjected to quasi-static compression load

This study investigates the energy absorption response of hybrid kenaf/glass fibre-reinforced epoxy when subjected to an axial quasi-static compression load with the effect of three stacking sequence of hybrid kenaf/glass reinforced epoxy. To characterise and evaluate the physical and mechanical properties, the hybrid composite tube was compared with synthetic glass fibre-reinforced epoxy. The hybrid and synthetic composites tube sampling were prepared by using automated filament winding technique which it provides the process with a proper fabricating procedure, quality control and stable process due to the mixture/ratio of the fibre and resin volume controlled by the winding speed and fibre tension. Crashworthiness mechanism of hybrid and synthetic composite tubes specimen were discussed to understand failure modes behaviour and energy absorption characteristics in term of quasi-static compressive response. Four different failure modes were observed in crushing tests as fibre/resin fracturing, local buckling, brittle fracturing and delamination. In the view of fibre stacking sequence aspect, fibre volume fraction in the hybrid specimen (HTS45-A) is a highest compared to other specimen and at the same time alleviates the capabilities in progressive failure with the significant increase 28% of initial peak load and 68% of the energy absorbed compared to the glass fibre-reinforced epoxy tube. Meanwhile, the glass fibre-reinforced tube showed the greatest specific energy absorption characteristics with the lowest initial peak load value with stability in progressive crushing behaviour. Also, experimental results have showed that kenaf fibre could be utilised as a potential reinforcement material in hybridisation with synthetic glass fibre composites as energy absorption tube application.

Vibration Evaluation of Laminated Hybrid Composite using Finite Element

the winning studies sample in composite is for the development of composite with carbon fiber. it's far crucial to break down the vibration behavior of composite for powerful usage in severa applications so that they experience with one-of-a-type types of stacking scenario and particular varieties of vibration with numerous stacking succession of filaments. CFRP s have immoderate firmness, and light-weight homes so their packages had been diverse. Be that as it may, CFRP s enjoy the ill effects of a high recurrence vibration. in this paper, numerical examinations have been finished to don't forget vibration behavior of composite overlaid shafts the use of ANSYS 18.1 programming. From the results, the effect of fiber stacking succession at the common frequencies are researched.

Effect of Interlaminated Carbon and Basalt Fiber Reinforced Hybrid Composites on Mode I Fracture Toughness

The fracture toughness and failure behavior of interlaminated hybrid composites were investigated. Hybrid interlaminated carbon and basalt fibers have been manufactured by fluid injection molding. The compact tension (CT) from hybrid composite panel has been used for Mode-I tension tests based on ASTM-D5045 standards. The experiment was aimed at investigating the stress intensity factor (KIC) of interlaminated hybrid composites having different stacking of carbon and basalt fibers. The experimental results showed that hybrid composites with configuration CBCBC (B2 code) have maximum average values about 5.8% and 2.0% higher than the C4 and B1 configurations, respectively. Replacing 20%, 30%, and 40% carbon by basalt fibers led to decrease in stress intensity factors (KIC) by 8.87%, 7:56%, and 5.46%, respectively. Additionally, SEM measurements showed that the dominant failures that occurred include delamination, pull-out fiber to epoxy and fiber splitting. Thus, the fracture toughness of composites is significantly influenced by interlaminated hybrid composite epoxies.

Experimental Research o n Hybrid Natural Glass Fiber Based Epoxy Composite

Polymeric substances fortified with engineered strands like glass, carbon, and aramid give addition of over the top firmness and vitality to weight proportion when contrasted with ordinary substances like wooden, concrete and numerous others. In spite of those favors present day examines are occurring inside the territory of home grown composites because of low primer cost and accessibility of simplicity. Hand arrangement approach is utilized for setting up the examples, with different weight division of bi-directional glass fiber. The proportion of filler is fixed with/without 10 wt.- %. Examples were cut from the created overlay with regards to the ASTM norms for various tests. The precise experimentation prompts self discipline of good estimated way parameters and texture factors that dominatingly impact the harm charge. It has been found that put on rate lower with developing fiber weight rate. Mechanical homes of composites are increments with development of fiber stacking. The mechanical and wear conduct of stuffed composites is more noteworthy propelled then unfilled composites.

Dynamic Characteristics of Twisted Composite Panels

Composite materials are being increasingly used in turbo-machinery blades because of their higher specific strength and stiffness, and these can be tailored through the variation of fiber orientation and stacking sequence to obtain an efficient design. Thus the dynamic characteristics of laminated composite twisted cantilever panels are of great importance in engineering applications. Analytical solutions are seldom capable of accurately analyzing these types of problems because of the complex orthographic nature of material and geometry. The finite element method (FEM) is the most commonly used numerical technique. The present research work deals with the review of finite element formulation of dynamic problems applied to orthotropic laminated plates and to carry out a parametric FEM analysis of laminated composite twisted curved panels. The effects of parameters like twist angle, stacking sequence and thickness, lamination angle, and orthotropic ratio on the natural frequencies and mode shapes of twisted cantilevered composite plates are investigated.

Effect of Chemical Treatment on Ramie / Rattan /Silicone Polymer Composites

During the most recent couple of years, regular strands have gotten considerably more consideration than any time in recent memory from the examination network everywhere throughout the world. These characteristic filaments offer various favorable circumstances over conventional engineered strands. Stagnant mechanical possessions of arbitrarily situated personally blended Ramie (Boehmeria nivea) and Rattan (Malay rotan) fiber fortified polymer composites, for example, flexural, Impact, hardness quality, water retention properties and so on, were examined as an element of fiber stacking according to ASTM measures. At first Silicone gum arranged was exposed to assessment of its ideal mechanical properties. At that point strengthening of the tar with Ramie (Boehmeria nivea) and Rattan (Malay rotan) fiber was practiced in three unique structures: molecule measure by utilizing advanced gum. Contemporary effort uncovers that mechanical possessions, for example, flexural, solidity, aquatic retention and so on of the Silicone pitch increments to significant degree when strengthened by the fortitude.