Hybrid Composite Laminates Research Articles

Influence of yarn-hybridisation on the mechanical performance and thermal conductivity of composite laminates

Recently, advanced composite materials have been widely used in numerous applications due to their superior properties. However, their sensitivities to damages during impact loading event limits their usage. In this regards, the influence of yarn hybridisation on the mechanical and thermal performance of composite laminates have been studied using low velocity impact, compression after impact (CAI), flexural and thermal conductivity tests. Two types of composite laminates were manufactured using hybrid yarns (S-glass and polypropylene [PP]) and S-glass yarns through the combination of commingling and core-wrapping methods and converted to non-crimp cross-ply preforms for both laminates. C-scan tests and cross-section microscopy examinations were adopted to identify the damaged areas of impacted laminates and explain the damage failures, which occurred during impact loadings. Results revealed that the hybrid laminates displayed higher damage area reduction compared to glass composites. Although the hybrid composite laminates illustrated considerably lower compressive strength, their residual compressive strength (damage tolerance) was significantly higher than glass composites. Fractography analysis has illustrated that the new damage failure modes such as intra-yarn cracks have been observed in the hybrid yarns laminates. These damage modes have contributed for higher energy absorpsion leading to an enhancement of the damage tolerance of the hybrid laminates. Furthermore, the incorporation of PP fibres resulted in a reduction of thermal conductivity of hybrid laminates compared to pure glass laminates.

Response of glass/carbon hybrid composites subjected to repeated low velocity impacts

This work investigated the effect of repeated low-velocity impacts at different energy levels on vinyl ester composite laminates. In particular, hybrid composite laminates made by carbon woven fabric and glass woven fabric impregnated by vinyl ester resin were subjected to 1, 5 and 10 impacts for three different energy levels (U=5 J, 10 J and 20 J). The multi-impact damage evolution was studied by combining several non-destructive techniques such as Pulsed Thermography, Electronic Speckle Pattern Interferometry and Ultrasonic C-scanning. Along with images of detected damaged areas, some impact parameters such as contact force, deflection and absorbed energy were provided.

Strain rate effect on the tensile properties of plain weave aramid, carbon, and glass fabric reinforced monolithic and hybrid composites

Abstract The tensile responses of three monolithic composites (aramid, carbon, and glass) and three different interply hybrid composite laminates (aramid/carbon, glass/aramid, and glass/carbon) were studied at quasi-static and intermediate strain rates. Monolithic composites were found to be more sensitive to strain rate than hybrid counterparts. The hybrids with glass layers had the highest sensitivity among the hybrid laminates. Tensile strengths of aramid, carbon, and glass monolithic composites improved by 15.2 %, 10.1 %, and 22.2 %, respectively, as the strain rate was increased from 0.001 s−1 to 10 s−1, while increases in tensile strengths of aramid/carbon, glass/aramid and glass/carbon hybrid laminates were 8.8 %, 17.7 %, and 5.2 %, respectively. Hybridization of glass with aramid gave the highest failure strain gain. Carbon layers located at the centre of the hybrid laminates resulted in increased tensile strength.

Vibration of variable stiffness composite laminate and hybrid composite laminate plates coupled to sloshing fluid

In the present article, Reddy shear deformation plate theory is employed to investigate the free vibration of vertical laminated composite plates coupled to sloshing liquid. Two different types of composite plate are considered; hybrid composite laminate (HCL) plate, which consists of two types of fiber, and variable stiffness composite laminate (VSCL) plate, which is made of curvilinear fibers. The applied Reddy shear deformation theory introduces a nonlinear through-thickness distribution for the transverse shear stress, and it satisfies the zero stress conditions at the bottom and top surfaces of the plate. The sloshing fluid, which is partly in contact with the plate, is modeled as ideal, and the bulging and sloshing modes related to that are calculated using the fluid velocity potential. The interaction between fluid and solid is modeled through the continuity equation and boundary conditions at the fluid–solid interface. To extract the vibrational characteristics of the structure coupled to fluid, a polynomial approximation based on the Rayleigh-Ritz method is employed. After validating the proposed methodology, a parametric study is conducted to show the effects of various parameters associated with the fluid and structure on the natural frequencies of the system.

Study on the interface bond strength of DP780 steel/CFRP composite laminate based on hot-press curing integration

The metal and carbon fiber reinforced plastic (CFRP) hybrid parts are increasingly used in automobile industry to meet the demand for vehicle weight reduction. The interface bond strength between metal and CFRP is the key to the part properties. The effects of different surface treatments on the interface bond strength of DP780 Steel/CFRP composite laminate based on hot-press curing integration were studied. Single lap test and single-leg bending (SLB) test were used to characterize the interface bond strength of the hybrid composite laminate. Interface failure mechanism was analyzed through surface roughness, fracture mode and fracture morphology. The experimental results showed that the steel surface treated by laser exhibited the highest surface roughness and the greatest surface energy in contrast to other surface treatments, such as degreasing, acid corrosion and grinding. The single lap test results showed that the laser-treated specimen had the maximum interface bond strength and there were a lot of fibers residues on the steel fracture surface. In SLB tests, there was no gap between the laser-treated steel and CFRP interface. The interface was bonded finely, which greatly improved the interface bond strength.

Effect of Hybridization Approach on Mechanical Performance of Jute-hemp/epoxy Hybrid Composite Laminates

ABSTRACT In this study, four-layered hybrid jute-hemp/epoxy composite laminates were fabricated by increasing and decreasing the number of layers of both jute and hemp reinforcements during stacking. Two jute(J) and hemp(H) controlled i.e., A(0J4H) and E(4J0H) and three jute(J)-hemp(H) hybrid i.e., B(1J3H), C(2J2H) and D(3J1H), composite laminates were fabricated. Composites were fabricated by hand layup followed by compression molding technique, and different mechanical tests (tensile, flexural, Charpy and drop weight impact) were performed. Results showed that hemp/epoxy laminate A(0J4H) revealed the highest tensile, flexural, Charpy and drop weight impact testing results followed by three hybrid composite laminates i.e., B(1J3H), C(2J2H) and D(3J1H), respectively. In hybrid composites, trend of mechanical properties was increased with the increase in number of plies of hemp reinforcements. The least mechanical testing results were presented by the E(4J0H) laminate because it was comprised of only four plies of jute reinforcement. Drop weight impact tested samples revealed that hybrid laminates C(2J2H) showed the least damage area in comparison with others due to the presence of equal number of jute and hemp plies. Also, within the same time duration, the highest force value was achieved along with less displacement by A(0J4H) laminate during drop weight impact test.

Analytical modelling of low-velocity impact response characterization of titanium and glass fibre reinforced polymer hybrid laminate composites

The low-velocity impact behaviour and energy absorption mechanisms of fibre​ metal laminates (FMLs) at different impact energy levels before the first composite failure are derived analytically using a mass–spring arrangement. Four FML layups comprise glass fibre/epoxy layers and titanium alloy Ti-6Al-4V sheets, unveiling the same total metal layer thickness. The impactor mass consequence is also predicted. The results specify that the deformation energy of FML constituents accounts primarily for the FMLs overall energy absorption, 86%–93%, and 87%–93%, with both membrane and bending strain energy, and membrane strain energy only, separately. Here, a higher percentage of energy is absorbed by FML 4/3–0.3, followed by FMLs 3/2–0.3(O), 3/2–0.4, and 2/1–0.6. FMLs are 16 % more impact resistant than equivalent monolithic titanium. Also, the predicted force history of FMLs is in good comparison with experiments at 30 J, with membrane energy only correlating well than with both membrane and bending energy. The estimated maximum force, entire energy absorption of FMLs is realistic with experiments at 30 J, 45 J, and 60 J. The predicted response of aluminium-based FMLs also matches well with experiments at various energy, preserving the presented model strength. Further, the behaviour of FMLs is to be comparable under low- and high-mass impactors. However, FMLs maximum force and energy absorption seem to be correspondingly lower and higher under a high-mass impactor. Higher impact resistance seems to be displayed by titanium- to aluminium-based FMLs. Also, the above FMLs appear to display higher total energy absorption under low- to high-velocity impact.

Experimental study of carbon/glass fiber-reinforced hybrid laminate composites with torsional loads by using acoustic emission and Micro-CT

In this work, a torsion experiment was carried out on composite specimens with different off-axis angles to study the damage-evolution behavior of carbon/glass fiber-reinforced hybrid composites. The results show that the off-axis angle can improve the toughness of the specimen during the torsion process and enhance anti-torsion performance in the early stage. After applying Micro-CT and scanning-electron-microscope (SEM) technology, the damage distribution for a composite specimen under torsion was determined. AE technology for monitoring the entire torsion process was also applied, and for damage characterization post-processing based on Fuzzy C-Means (FCM) cluster analysis was performed on collected AE signals. AE signals were clearly divided into three categories that correspond to three damage modes, and frequency characteristics of the AE signal for each damage mode were found. The results can offer guidance for structural health monitoring (SHM) for composites under torsion.

Hybridization Effect on Mechanical Properties of Basalt/Kevlar/Epoxy Composite Laminates.

The present work investigates the fabrication of Kevlar/epoxy and basalt/epoxy and Kevlar/basalt/epoxy hybrid composite laminates and compares their mechanical properties. Mechanical characterization tests, including tension, flexural, impact and hardness tests, as per ASTM standards, were conducted on coupons cut out from the fabricated composite panels. A hand layup fabrication technique was used to fabricate composite panels with seven layers in them. Eight such laminates, with two containing pure Kevlar/epoxy and basalt/epoxy and the remaining ones containing Kevlar/basalt, were stacked in different sequences and impregnated in an epoxy matrix to provide a hybrid configuration. The microscopic examination of the fabricated laminates revealed that there was good bonding between the reinforcements and matrix material. Out of the eight composite panels including the hybrids, the ones with the pure basalt/epoxy exhibited more tensile and flexural strength than its Kevlar/epoxy counterpart due to its higher density value. The tensile and flexural strength of the hybrid laminates (i.e., combinations of basalt/Kevlar/epoxy) showed values in between pure basalt/epoxy and Kevlar/epoxy laminates in general. A similar trend was observed in terms of hardness and impact strength for the fabricated composite laminates.

Failure mechanism of carbon/ultra-high molecular weight polyethylene twill fiber reinforced hybrid laminates under ballistic impact

Carbon fiber reinforced plastic (CFRP) have been widely used in recent years for their high specific strength and stiffness. However, due to the high brittleness and low elongation, its application in protection engineering was limited. The introduction of other ductile fibers can ameliorate this shortcoming. In this paper, laminated construction and failure mechanism of twill carbon fiber and ultra-high molecular weight polyethylene (UHMWPE) fiber hybrid composite laminates under ballistic impact were comprehensively studied. Three different interface properties were characterized by peeling test. The simulation results were in good agreement with the ballistic impact experimental results. The sample of 4C4P with carbon fiber in the front and UHMWPE fiber in the back shows the best impact energy absorption performance,with the specific energy absorption increased by 92.22%. Based on the computed tomography (CT) scanning, delamination damage cloud images of the composite laminates were presented for the first time. The improvement of interlayer fracture toughness can enhance the impact resistance of laminates, which mainly depending on the stacking sequence and interface properties. It provided a new idea for the study of impact damage of laminated structures.

A multiobjective discrete combination optimization method for dynamics design of engineering structures

AbstractThis paper presents a new multiobjective discrete optimization method for the engineering design of dynamic problems. A discrete combinatorial optimization problem is solved using a particle swarm optimization algorithm coupled with a stair‐form interpolation model. To address multiobjective optimization issues, a weighted average approach is implemented to convert the multiobjective optimization problem into an equivalent single‐objective optimization problem. Design constraints are taken into consideration by using the penalty function strategy. The proposed method is first verified with a 10‐bar truss structure design problem, where the cross‐sectional area of each bar is optimized to minimize both volume and node displacement. Second, the dynamic issue for hybrid composite laminates is investigated by maximizing the fundamental frequency and minimizing the cost. The results reveal that the optimized results generated by the proposed method agree well with those from other approaches.

Improving the mechanical performance and impact damage tolerance of glass composite laminates via multi-scales of hybridisation

The glass fabric composite laminates are widely used in the various applications compared to the non-crimp cross-ply laminates due to their high fracture toughness and better impact damage tolerance. However, their in-plane properties are limited owing to the interlacements of their warps and wefts. In this regard, an experimental investigation of the multi-scales hybridisation (i.e. yarns-hybridisation and hybrid layers methods) for improving the mechanical performance, and impact damage tolerance of continuous glass fibre-epoxy composite laminates has been presented. The two types of composite laminates that have intra yarns (i.e. hybrid yarns) and inter-ply (i.e. hybrid layers) with multi-stacking sequence were manufactured via vacuum infusion process and then compared with 2D hybrid fabrics and glass cross-ply composite laminates with respect to in-plane properties and impact damage tolerance respectively. The tensile strength properties and the low-velocity impact response of all laminates were identified by using tensile strength and drop-weight impact tests at different energy levels. The impact damage tolerance was studied by using compression-after-impact (CAI) strength tests, measuring the residual compressive strength of the damaged laminates. The damage characterisation based on impact and compression, and compression after impact was also examined using scanning electronic microscopy (SEM). The outcome of this investigation demonstrated that the intra- and inter-ply hybrid composite laminates showed higher tensile strength and modulus of elasticity, compared to hybrid fabric composites. Moreover, the impact damage tolerances of intra- and inter-ply hybrid laminates were found to be slightly higher than the non-crimp cross-ply glass laminates for certain-impact energy levels.

Influence of stacking sequence on mechanical properties and moisture absorption of epoxy-based woven flax and basalt fabric hybrid composites

Hybrid composite laminates (HCL) were prepared by lay-up molding using a hot-press bed for reinforcing epoxy-based woven flax and basalt fabric composites. Mechanical properties and moisture absorption of HCL were measured, and the fracture surface was examined by scanning electron microscopy (SEM). The present results indicated that the mechanical properties of HCL are strongly dependent on the sequence of fiber reinforcement. HCL (S2, S3, S4, S5) with symmetric stacking sequences that increase with basalt fibers (wt %) showed a positive hybridization effect on mechanical properties and curve characteristics. However, the mechanical properties of S7 (asymmetric stacking) were lower than S3, S4, S5 (symmetric stacking), which indicated that symmetric stacking sequences of HCL had superior mechanical performance compared with the cross arrangement of HCL. The moisture absorption of HCL samples immersed in water at 26 °C showed the Fickian behaviour up to 42 days and were not affected by altering the stacking sequence on HCL. The SEM of the fracture surface, fiber-matrix bonding, and interfacial bonding of flax-basalt fabric HCL were also presented.

Experimental investigation on mechanical properties of Basalt/Jute/SiC reinforced hybrid polymer composites

Recent years, researchers focuses on hybridization of composite with natural fiber reinforcement and adding fillers for improving thermal and mechanical thermal behaviour of composites. These natural fiber reinforced bio polymers acts as partial eco-friendly materials. It makes the need for creating design database for hybrid composite materials.. In the present work, hybrid composite laminates were fabricated with Basalt and Jute fiber reinforcements using the hand layup technique with 5% and 10% Silicon carbide and also absence of it. There are six hybrid composite laminates were fabricated along with five stacks alternative fiber layers and Five stacks of basalt and jute fiber reinforced polymer composite laminate with 5% and 10% SiC filler. All such composite laminates are compared with five stacks of five layered composite laminates made of individual Basalt and Jute fiber to analyse mechanical behaviours like tensile, flexural and wear properties using ASTM standards. Results were analysed and fractured surfaces were examined using scanning electron microscope.

Numerical investigation on perforation resistance of glass-carbon/epoxy hybrid composite laminate under ballistic impact

Fiber reinforced composite materials are widely used in automotive and aerospace industries because of their excellent specific mechanical properties compared to conventional metals. In this article, the performance of hybrid composite laminate containing three layers of glass/epoxy and two layers of carbon/epoxy under ballistic impact loading is presented based on numerical investigations. The energy absorption capacity of hybrid composite laminate under various impact velocities (400 m/s, 450 m/s, and 500 m/s) and various layer combinations are analyzed using ANSYS-Explicit Dynamic module. Result shows that stacking sequence [G-C-G-C-G] gives better performance towards the impact loading due to perforation. Further, Design of Experiment (DOE) studies have been carried out to find out the effect of various parameters on the performance of hybrid composite laminate under impact loading.

Effect of fiber layering arrangement on mechanical and wear properties of flax/sisal hybrid composite laminates

To promote ecofriendly structures in engineering applications, natural fibers are preferred over the synthetic fibers in fiber reinforced polymer composite materials. However, understanding the behaviour of the natural fiber composite laminates under static and dynamic load conditions is an important aspect for the correct usage of these materials. In the present study, the effect of layering arrangement of hybrid laminates made of natural fibers on mechanical and wear characteristics have been concentrated on. In order to study the effect of layering arrangement efficiently, two different natural fibers, flax and sisal, having considerable difference in elastic modulus were preferred. All the natural fiber hybrid laminates were prepared by hand layup method. The fabricated natural fiber laminates were tested for mechanical and wear characteristics as per the ASTM standards. The fiber layering arrangement with high modulus flax fiber plied in the surface layer showed improved mechanical and wear characteristics that is beneficial for structural applications.

Bow structure damage analysis for hybrid coir-glass fiber composite fishing boat hull subjected to front collision load

Abstract Hybridization of natural and synthetic fibers has the ability to improve composite performance. It means that the combination of natural fibers such as coir, jute, bamboo, and sisal with synthetic or glass fiber can broaden the role of the composite material, especially for structural application. This study developed a finite element simulation to investigate the damage to the bow structure of the fishing boat hull, which was produced using hybrid coir-glass fiber composite (HCGFRP) material subjected to front collision load. The experimental measurement was conducted to determine the mechanical properties of four hybrid composite laminates defined based on the differences in their layers number, fiber types, and orientation angle. Moreover, a numerical simulation model was applied to the traditional fishing boat colliding with fishery harbor quay, and the scenario was defined by varying the boat speed and the types of laminates adopted on the hull structure. The results showed the damage level for the bow structure of the HCGFRP boat due to the collision accidents, while the numerical findings are expected to be used as the basic knowledge in applying the hybrid coir-glass fiber laminates composite as an alternative hull construction material.

Moisture absorption behavior of hybrid composite laminates consist of natural and glass fiber

Natural fibers have advantages over synthetic fiber in economic and environmental benefits. The use of natural fiber is an innovative finding. The use of these fibers can increase the value of these fibers. Soon, natural fibers are expected to replace synthetic fibers in several applications, such as manufacturing sectors and automotive components. However, natural fibers lack information compared with other fiber such as carbon and glass fiber related to their mechanical behavior. This research investigates the effect of stacking sequences on water absorption in natural and hybrid composites consisting of glass fiber under varying layers of natural fibers. The different natural fibers were used, such as jute, agel and bamboo. Several specimens of natural fibers are combined with glass fibers with different arrangements to produce a hybrid composite. Samples were made using the hand lay-up method. Three types of stacking sequence were implemented: NF/GF/GF/GF/NF, GF/GF/NF/GF/GF, and NF/NF/NF/NF (where NF represents natural fiber layers and GF means glass fiber layers). The study evaluated the percentage of moisture absorption in the corresponding property of the specimen after 3, 6, 24, 48 h of water immersion and then compared it with the dry sample. The results showed that the highest water absorption was occurred at the B/B/B/B specimen with 11.12% and then followed by B/GF/GF/GF/B specimen with 9.21%.

Study on underwater vibro-acoustic characteristics of carbon/glass hybrid composite laminates

Abstract At present, in addition to the high-strength alloy steel still used in the main load-bearing structure of foreign nuclear submarines, many composite materials have been used for non-load-bearing components, and the common laminate is the main form of the composite plate and shell. The composite laminate with a carbon/glass hybrid material has excellent structural mechanical properties. The vibration and acoustic radiation theories of the composite laminate were analytically deduced, the effect of ply parameters in hybrid shell plates was analyzed, and the influence of the hybrid ratio on the stiffness of shell plate was also investigated. Furthermore, according to the theoretical description, the typical carbon/glass hybrid shell plate was designed and the experimental comparison on the vibro-acoustic properties with a steel plate was carried out. The results showed that the mass and stiffness of a 12 mm carbon/glass hybrid shell plate were only 30 and 70% compared with an 8 mm steel plate. The mass and stiffness of a 15 mm carbon/glass hybrid shell plate were about 40 and 160% of that of an 8 mm steel plate, and its vibration and noise reduction performance was far superior to the steel plate. Therefore, the composite shell plate can achieve excellent acoustic performance while meeting the structural-functional indicators.

Sonlu Elemanlar ve İstatistiksel Yöntemler Kullanılarak Ankastre Tabakalı Hibrit Kompozit Plakaların Burkulma Analizi

In this study, the critical buckling load of hybrid composite plates with three layers was analyzed using numerical and statistical methods. Laminated hybrid composite plates were designed using glass-epoxy, boron-epoxy, carbon-epoxy, and metal. The outermost layers of the plates were modelled using fiber reinforced composite materials whereas the innermost layer of plates was created using Aluminum material (Al2024-T3). Numerical buckling behavior was calculated using finite element software ANSYS. Analysis of signal-to-noise ratio was utilized to decide the effects and optimal levels of the plates and their fiber orientation angles on buckling load. Analysis of variance at the 95 % confidence level was employed to indicate the control factors which have significant effect on the buckling responses.