Hybrid Laminates Research Articles

Nonlinear Dynamics of Thick Hybrid Composite Laminates Subjected to Low-Velocity Impact and Various Preloading.

The composite primary structures of railway vehicles endure not only mechanical loads including tension, compression, bending, and torsion, but also external impacts, such as by the crushed stone in ballast. In the present study, the low-velocity impact response of preloaded hybrid composite laminates with different thicknesses is examined using a finite element method based on a progressive damage model. The hybrid plate consists of carbon fiber-reinforced unidirectional and woven prepregs. The progressive damage model, based on the 3D Hashin model, is validated by experiments on hybrid laminate, and further compared with the post-impact appearance obtained from CT scans. Preloading, considered to be tensile, compressive, or shear, corresponds to different positions in a bending beam with flanges and a web. Finally, the effects of impact energy, preloading, thickness, and impact angle on the dynamic response are analyzed, with an emphasis on new results and failure mechanism analysis comparing the influence of preloads under a given impact energy and different thicknesses.

Bending behavior of hybrid laminates made of aluminum and wood for sustainable lightweight structures

Substituting fiber-reinforced plastics (FRP) with wood-based materials significantly increases the sustainability of fiber-metal laminates (FML). Therefore, the present work compares the three-point bending behavior of simple wood laminates with that of hybrid aluminum-wood laminates. Wood laminates consisting of four layers of 1-mm-thick birch veneers were adhesive-bonded with a single 1-mm-thick sheet of commercial aluminum alloy EN AW-6016-T4. Longitudinal, transverse, and bidirectional orientations of the wood fibers were considered. Prior to three-point bending, the laminates were exposed to different moistures and temperatures. The bending behavior was analyzed in terms of (i) the maximum bending force, (ii) the bending angle at maximum bending force, and (iii) the strains monitored on the side surface of the laminates during each bending test. The simulation software LS-DYNA was used to create a finite element (FE) model of the bending procedure, which considered the experimentally determined material properties. In general, the hybrid aluminum-wood laminates showed a larger bending angle at maximum bending force than simple wood laminates. The maximum bending force of the laminates gradually decreased with increasing moisture content. The FE model was able to predict the bending behavior at different moisture and temperature conditions.

Natural frequency analysis of a multi-scale hybrid annular plate with carbon fiber and agglomerated graphene platelets

This study investigates the natural frequency behavior of a hybrid composite annular plate, combining graphene platelet (GPL)-reinforced polymer layers with carbon fibers (CFs) for enhanced strength, stiffness, and damping. The nanocomposite matrix is characterized using the Eshelby–Mori–Tanaka model and integrated with CFs to form a high-performance hybrid laminate. Governing equations, derived via first-order shear deformation theory, are solved using a Hamiltonian-based finite element method. Parametric analyses reveal that GPL addition increases natural frequency exponentially up to 1%, then linearly. GPL patterns matter most at higher fractions, with the X pattern being optimal, while agglomeration reduces natural frequency.

Corrigendum to “Machine learning-based optimization of impact-resistant layups for FRP hybrid laminates in yachts” [Ocean Eng. 324 (30) (2025) 120600

Corrigendum to “Machine learning-based optimization of impact-resistant layups for FRP hybrid laminates in yachts” [Ocean Eng. 324 (30) (2025) 120600

Low-velocity impact resistance of bio-inspired interlayer hybrid composite laminates with a gradient waviness structure.

Low-velocity impact resistance of bio-inspired interlayer hybrid composite laminates with a gradient waviness structure.

Machine learning-based optimization of impact-resistant layups for FRP hybrid laminates in yachts

Machine learning-based optimization of impact-resistant layups for FRP hybrid laminates in yachts

Enhancing puncture resistance and mechanical properties of hybrid polymer composites reinforced with silica nanoparticles for aerospace applications

ABSTRACT This research focuses on developing lightweight and rigid defense structures using hybrid polymer composites reinforced with silica nanoparticles (SiNPs). The primary objective is to enhance the puncture resistance, mechanical properties, structural efficiency, and cost-effectiveness of these composites for defense, military, and marine applications. To achieve these goals, advanced materials and reinforcement techniques, such as optimized fibre orientation and nanoparticle inclusion, were employed. The composite laminates were fabricated using bidirectional interply 0-degree Kevlar, AR glass, and 45-degree basalt fibre woven matrices combined with an epoxy resin matrix. Silica nanoparticles were incorporated at weight percentages (wt.%) of 0, 1.5, 3, 4.5, and 6. A quasi-static sequence method 0 2 ∘ K / 45 2 ∘ B / 0 2 ∘ G / 45 2 ∘ B / 0 2 ∘ K was utilized to further enhance the mechanical and structural properties of the hybrid composites. Mechanical performance was characterized through various tests, including puncture resistance, tensile, flexural, interlaminar shear, Izod impact, and Charpy impact tests. Among the composites tested, the hybrid laminate reinforced with 4.5 wt.% silica nanoparticles exhibited superior mechanical properties, achieving puncture strength, tensile strength, flexural strength, interlaminar shear strength, Izod impact energy, and Charpy impact energy of 112.09 MPa, 167.93 MPa, 109.93 MPa, 17.03 MPa, 1598.1 J/m, and 834.9 J/m, respectively. These findings highlight the effectiveness of silica nanoparticle reinforcement and precise fibre orientation techniques in enhancing the mechanical performance of hybrid polymer composites. This study provides a strong foundation for developing high-performance, lightweight structures for advanced engineering applications.

Enhancing the temperature resistance of hybrid basalt/glass epoxy laminates

AbstractThis study examines the tensile properties of hybrid basalt/glass epoxy laminates, specifically focusing on the impact of fiber arrangement on these properties at high temperatures. The composite laminates were manufactured utilizing the hot compression molding technique and underwent tensile testing at 25–400°C. Thermogravimetric analysis (TGA) and chemical composition analysis were used to evaluate the thermal and chemical features of basalt fiber (BF) and glass fiber (GF). The tensile strength and elastic modulus of G₄B₄G₄, B₂G₈B₂, B₆G₆, B₄G₄B₄, G₂B₈G₂, and B₁₂ demonstrated slight enhancements or remained relatively stable when the temperatures increased from ambient temperature (25°C) to 100°C; however, the laminate G₁₂ exhibited the weakest performance. It was also noted that the laminates with a larger percentage of basalt fiber (BF) showed superior performance compared to those with a larger percentage of glass fiber (GF). This was especially evident when the basalt fiber (BF) was used in the outer layer, leading to enhanced performance from ambient temperature up to 400°C. Nevertheless, all the laminates’ tensile strength and elastic modulus significantly decreased under temperatures ranging from 200 to 400°C.Highlights Higher ratios of BF enable hybrid laminates to show more thermal stability. At elevated temperatures, BF laminates perform better than GF Laminates maintain tensile strength up to 100°C but decrease at 200°C. BF in outer layers increases thermal resistance.

Translaminar fracture behavior of hybrid woven-ply peek thermoplastic laminates under isothermal and kerosene flame exposure

The growing demand to use thermoplastic matrix composites in aeronautic has been confronted with the need to understand the fracture mechanisms under different service conditions. Thus, the present work aims at studying the influence of different thermal stress conditions on the fracture behavior of PolyEther Ether Ketone-reinforced carbon/glass fiber hybrid laminates (CG/PEEK), as a function of heating temperature and fire exposure time. Compact Tensile (CT) specimens are exposed to isothermal (from 350°C to 550°C in a high temperature furnace) and critical service conditions (kerosene flame exposure characterized by a heat flux of 116 kW/m2 and a temperature of 1150°C) exposure conditions. Monotonic tensile tests are then conducted to assess the mode I translaminar fracture toughness (FT) at room temperature. Crack propagation is monitored during mechanical loading using a Digital Image Correlation (DIC) device combined with a binarization algorithm. Then, the G-R curves have been obtained from the compliance method. Under isothermal conditions, the residual mechanical properties degrade as temperature increases, particularly once thermal decomposition is about to start, due to the formation of porosities and extensive delamination. Under flame exposure, the microscopic and tomographic observations reveal thermally- and mechanically-induced damages with a heterogeneous distribution due to temperature gradients within the plies of laminates. Depending on the pyrolysis degree of each ply, the load bearing capabilities of the plies gradually deteriorate from the exposed to the opposed side. The critical FT values shows a decreasing trend (as a function of fire exposure time) with increasing ply number of charred regions through the thickness.

Experimental Investigation and Analysis of Hybrid Laminates

Hybrid composites have gained significant attention from researchers due to their potential as reinforcement materials for composites. This is primarily because of the numerous advantages they offer, including low density, low cost, renewability, biodegradability, and environmental safety, along with mechanical properties that are comparable to those of synthetic fiber composites. In this study, hybrid composites made from natural fibers and glass fibers were fabricated using epoxy resin and a combination of the hand lay-up method and the cold press method. Specimens were cut from the fabricated laminate according to ASTM standards for various tests, including tensile, flexural, and impact tests. The woven fiberglass hybrid composites demonstrated a notable improvement in tensile strength. Consequently, these high-performance hybrid composites display enhanced mechanical characteristics and have wide-ranging engineering applications in industries such as transportation, aeronautics, naval, and automotive.

Study of the behavior of damaged low-velocity impact carbon/epoxy/AL2024-T3 hybrid laminates

Aluminium and layered composite structures currently play a crucial role in the aviation sector. These structures may be susceptible to inadvertent impacts from several sources. Low-velocity impact is a type of unintended aggression that causes severe harm to composite materials and can greatly diminish their residual resistance. This research presents a novel stack of unconventional hybrid laminates aimed at improving both stiffness and elasticity through a multi-material design. We focus on analyzing the main factors responsible for impact damage in hybrid structure. Tie contact were used between plies of the composite plate in all models. Using the HASHIN criterion, we analyze the impact velocity, impact sequence, composite thickness, impact energy level, impact efforts, and damaged zones in the composite, matrices, and fibers. The primary results indicate that both impact energy and composite thickness have a substantial influence on the energy absorbed by the composite and the impact exerted in the affected area.

Ballistic impact response of fibre metal laminates based on ramie fibre woven reinforced polyester

This research focused on evaluating the ballistic impact behavior of polyester-reinforced woven ramie fibers combined with aluminum fiber metal laminates (FMLs). The materials were structured in four specific configurations: two types of ramie composites (2-layer and 3-layer) and two FML configurations FML 2/2 and FML 2/3. Ballistic performance was assessed through both experimental and numerical testing under a controlled firing angle of 90 degrees with 9 mm projectiles. The findings clearly showed that the FMLs had superior energy absorption capabilities compared to pure ramie composites, with the FML 2/3 configuration standing out, absorbing 52.69 J of energy. This highlights the enhanced ballistic resilience of hybrid laminates, especially with increased composite layers. Therefore, the FML, particularly the FML 2/3, exhibits a significantly higher energy-absorbing capacity, making it more effective in reducing projectile performance post-penetration. The FML 2/3 configuration showed the greatest reduction in residual velocity in both experimental and simulation results, indicating superior effectiveness in absorbing ballistic energy compared to the other configurations. This finding suggests that adding layers to the composite, especially in the FML configuration, enhances the material's resistance to projectile penetration and effectively decreases the projectile's residual velocity. However, additional research is necessary to gain a comprehensive understanding of the high-velocity performance of thermoplastic fiber metal laminates (FMLs), particularly for their potential use in industrial applications.

Experimental investigation on the impact resistance and damage mechanism of carbon/glass unidirectional and woven hybrid laminates

AbstractThe mechanical properties of hybrid fiber composite laminates are affected by the hybrid ratio as well as the stacking sequences, to investigate the effect. In this paper, the effects of the hybrid ratio and stacking sequences on the impact resistance and residual compression properties of carbon/glass unidirectional and woven hybrid laminates are investigated. The use of acoustic emission technology enables the real‐time monitoring of the impact and compression damage processes of carbon/glass composite laminates with varying hybrid ratios and stacking sequences, thereby facilitating the elucidation of the underlying failure mechanisms and the evolution of the laminates. The findings indicated that laminates with symmetrical stacking demonstrated superior impact resistance, resilience, and residual compression properties compared to those with asymmetrical stacking when subjected to high‐energy impact. Sandwich stackings demonstrate superior energy absorption properties relative to alternate‐stacking laminates, although they exhibit diminished residual compression properties. The impact resistance of laminates with a high carbon content under a sandwich stacking sequence is poor. In the context of alternating symmetric stacking, the impact resistance of the laminate is not significantly influenced by the carbon content. The results of the acoustic emission analysis indicate that the damage is minimized when the stacking sequence is alternating symmetry and the impact side is a woven material.Highlights Enhancing impact resistance of composites through hybrid structure research. Report the optimal parameters of the effects on the impact resistance of the composite. The VMD method is used to determine the percentage of damage types in the laminate.

Advanced hybrid laminates: elastomer integration for optimized mechanical properties

Abstract Interleaving elastomeric films into polymeric composite materials is a promising technological solution to manufacture components with localized functionalities. To optimize processing time and reduce testing costs, there is an urgent need for modeling strategies to predict the effect of hybridization based on the fundamental properties of singular constituents. In this work, three different laminates with varying numbers and positions of elastomeric layers were manufactured and mechanically tested in flexural configuration. The digital image correlation (DIC) technique is employed to evaluate the displacements and the strain field on the surface of the sample. A numerical framework for the prediction of the mechanical response, including damage initiation and evolution, was developed and validated against experimental data. The numerical results showed significant agreement with the experiments, reporting a maximum mismatch of about 10% in strain distribution and about 2% in the ultimate load. Additionally, degradation trends in the load vs. deflection curves were always consistent. Analysis of the fractured surface and predicted failure modes further demonstrated the reliability of the method.

Tensile behavior of mechanical joint for GFRP/metal mesh hybrid laminate after low‐velocity impact

AbstractThis work investigates the effect of metal mesh reinforcement on the low‐velocity impact (LVI) resistance and post‐LVI tensile properties of bolted‐joint glass fiber‐reinforced polymer (GFRP). With the self‐designed fixtures, a total of nine different specimen types were tested, varying in stacking sequences and configurations. The analysis of the displacement‐force curves, damage morphology, and the progression strain contour captured by the digital image correlation (DIC) technology revealed that the incorporation of metal mesh disperses impact energy, and alters the stress distribution during tensile loading, thus, the compressive stress above the bolt hole is partially taken up by the tensile force below. Specifically, under an incident energy of 9 J, the metal mesh‐reinforced ply A specimens show a 10.17% increase in maximum contact force and a 36.63% enhancement in tensile ultimate strength compared to the unreinforced specimens.Highlights Inserted metal mesh to strengthen the bolted‐joint performance of post‐LVI GFRP. Self‐designed fixtures and DIC for LVI and post‐LVI tensile tests. Added metal mesh can effectively avoid concentrated failure in pure GFRP. At the same layup, up to 36.63% rise in bearing loading of hybrid laminate.

Experimental Study on Mechanical Performance of Single-Side Bonded Carbon Fibre-Reinforced Plywood for Wood-Based Structures.

In addition to the traditional uses of plywood, such as furniture and construction, it is also widely used in areas that benefit from its special combination of strength and lightness, particularly as a construction material for the production of finishing elements of campervans and yachts. In light of the current need to reduce emissions of climate-damaging gases such as CO2, the use of lightweight construction materials is very important. In recent years, hybrid structures made of carbon fibre-reinforced plastics (CFRPs) and metals have attracted much attention in many industries. In contrast to hybrid metal/carbon fibre composites, research relating to laminates consisting of CFRPs and wood-based materials shows less interest. This article analyses the hybrid laminate resulting from bonding a CFRP panel to plywood in terms of strength and performance using a three-point bending test, a static tensile test and a dynamic analysis. Knowledge of the dynamic characteristics of carbon fibre-reinforced plywood allows for the adoption of such cutting parameters that will help prevent the occurrence of self-excited vibrations in the cutting process. Therefore, in this work, it was decided to determine the effect of using CFRP laminate on both the static and dynamic stiffness of the structure. Most studies in this field concern improving the strength of the structure without analysing the dynamic properties. This article proposes a simple and user-friendly methodology for determining the damping of a sandwich-type system. The results of strength tests were used to determine the modulus of elasticity, modulus of rupture, the position of the neutral axis and the frequency domain characteristics of the laminate obtained. The results show that the use of a CFRP-reinforced plywood panel not only improves the visual aspect but also improves the strength properties of such a hybrid material. In the case of a CFRP-reinforced plywood panel, the value of tensile stresses decreased by sixteen-fold (from 1.95 N/mm2 to 0.12 N/mm2), and the value of compressive stresses decreased by more than seven-fold (from 1.95 N/mm2 to 0.27 N/mm2) compared to unreinforced plywood. Based on the stress occurring at the tensile and compressive sides of the CFRP-reinforced plywood sample surface during a cantilever bending text, it was found that the value of modulus of rupture decreased by three-fold and the value of the modulus of elasticity decreased by more than five-fold compared to the unreinforced plywood sample. A dynamic analysis allowed us to determine that the frequency of natural vibrations of the CFRP-reinforced plywood panel increased by about 33% (from 30 Hz to 40 Hz) compared to the beam made only of plywood.

An Experimental Study on Low-Velocity Impact Behavior of Carbon Fiber/Pineapple Leaf Fiber Hybrid Laminates for Automotive Applications

ABSTRACT This work characterizes the low-velocity impact (LVI) failure behaviors of three bio/synthetic hybrid laminates based on carbon fiber (C) and pineapple leaf fiber (P). The effect of aluminum (A) addition and its position were investigated by flexural tests, peak force, force–displacement curves, energy–time curves, visual inspection, and infrared thermography (IR). The flexural tests reveal that fiber-reinforced polymer (FRP) CPC composites exhibit superior flexural properties than fiber metal laminates (FMLs). FMLs with aluminum as skin sheets (ACPCA) show a 62.2% improvement in flexural strength (312.02 MPa) over those with internal aluminum (CAPAC). LVI results show that FMLs outperform FRP in impact performance, with ACPCA and CAPAC achieving peak force improvements of 266.22% (2.71 kN) and 209.50% (2.29 kN) over CPC (0.74 kN), respectively. The results emphasize the significance of A position, where ACPCA exhibits full rebound behavior while CAPAC shows partially rebound at 15J impact energy. Visual inspection and IR results corroborate LVI findings, indicating increased delamination at higher energies. Notably, IR provides critical insights into damage progression and internal structural changes, highlighting areas of delamination and deformation around V-type damage. These results suggest that the ACPAC provides a balance between bending and impact resistance, assisting material selection in automotive applications.

Micro-Level Hybridization of Steel, Glass, and Polypropylene Filaments via Air Texturing: Mechanical and Morphological Analysis

The increasing application of fiber-reinforced polymer (FRP) composites necessitates the development of composite structures that exhibit high stiffness, high strength, and favorable failure behavior to endure complex loading scenarios and improve damage tolerance. Achieving these properties can be facilitated by integrating conventional FRPCs with metallic materials, which offer high ductility and superior energy absorption capabilities. However, there is a lack of effective solutions for the micro-level hybridization of high-performance filament yarns, metal filament yarns, and thermoplastic filament yarns. This study aims to investigate the hybridization of multi-material components at the micro-level using the air-texturing process. The focus is on investigating the morphological and the mechanical properties as well as the damage behavior in relation to the process parameters of the air-texturing process. The process-induced property changes were evaluated throughout the entire process, starting from the individual components, through the hybridization process, and up to the tape production. Tensile tests on multifilament yarns and tape revealed that the strength of the hybrid materials is significantly reduced due to the hybridization process inducing fiber damage. Morphological analyses using 3D scans and micrographs demonstrated that the degree of hybridization is enhanced due to the application of air pressure during the hybridization process. However, this phenomenon is also influenced by the flow movement of the PP matrix during the consolidation stage. The hybrid laminates exhibited a damage behavior that differs from the established behavior of layer-separated metal fiber hybrids, thereby supporting other failure and energy absorption mechanisms, such as fiber pull-out.

Experimental and numerical investigation of fracture characteristics in hybrid steel/composite and monolithic angle-ply laminates

This study investigated the fracture characteristics of hybrid laminates consisting of CorTen steel and carbon fibre-reinforced polymer composites under quasi-static loading, both experimentally and numerically. The hybrid laminates are classified into two groups: one featuring alternative overlaying of steel and composite, and the other with symmetric cross-ply and angle-ply configurations overlaid within steel layers. The effects of layup sequence and composite-layer ply orientation on the fracture behaviour are examined. Experimental results revealed these factors influenced the fracture behaviour and load-carrying capacity. A semi-analytical framework is developed to determine the interlaminar stresses and assess interfaces susceptible to delamination, identifying whether these stresses are primary or secondary factors (combined with other fracture modes) in the experimentally observed fracture mechanisms. Angle-ply laminates, known for exhibiting mode III delamination at dissimilar interfaces, served as a baseline configuration to establish a “characteristic distance” for the average stress fracture criterion. This criterion is first utilised to predict mode III delamination in angle-ply laminates and subsequently, using the same characteristic distance in the quadratic average stress criterion, for mixed-mode I/III delamination in hybrid laminates. The predicted fracture stresses closely agreed the experimental results.

Influence of Fibre Stacking Sequence on Impact Resistance and Residual Strength in Flax/Basalt Hybrid Laminates

Influence of Fibre Stacking Sequence on Impact Resistance and Residual Strength in Flax/Basalt Hybrid Laminates