Hybrid Composite Beams Research Articles

Enhancing mode-II delamination resistance of hybrid woven composite materials of glass/Kevlar fabrics by stitching with Kevlar threads

This study analyzes the effects of stitching a hybrid composite beam on its Mode-II delamination to enhance the bonding between a Kevlar-Kevlar interface. The material under investigation is a composite material manufactured from fiberglass and Kevlar fabrics stitched together with Kevlar threads before the infusion of epoxy resin. End-notched flexure tests and multiscale finite element simulations are conducted to validate a glass/epoxy composite with a glass-glass interface. Calibrated simulations are then used to perform a parametric study on stitching parameters, including stitch spacing, pitch, and direction on a composite with a Kevlar-Kevlar interface. The parametric study on Kevlar-Kevlar specimens revealed an average improvement of 17 % in maximum load capacity and 103 % in tangent stiffness in stitched specimens compared to unstitched specimens. Additionally, increasing stitch density up to 0.02 mm−2 significantly enhances mechanical performance, while higher densities do not provide significant additional improvements.

Experimental and Numerical Studies on the Vibration of Hybrid Composite with an Edge Crack

The hybrid composite plate is increasingly used in marine, robotic arm, and other applications. Edge crack is the greatest common fault in the structural systems during its working time. In this research, the successful fabrications of a hybrid composite of epoxy-based composites reinforced with bamboo and glass fibers have been done to examine the vibration characteristics under free vibration. First-order shear deformation theory is used to study the fundamental natural frequencies of asymmetrically hybrid composite beam with edge cracks for cantilever beam boundary conditions. Both numerical (FEM) using ABAQUS software and experimental investigations are done for the vibration analysis of unidirectional bamboo/glass fiber epoxy hybrid composite (BGHC) beam with edge cracks using fracture mechanics theory. It is observed that implications edge crack with different crack depth and various fiber weight ratio parameters have a major effect on vibration analysis. Also, it is clear that the natural frequencies of the hybrid composite are significantly affected due to the fiber weight ratio and crack depth of the hybrid composite materials. So, crack lengths are playing a vital role in the dynamic or vibration characteristics of the hybrid composite materials. The results of natural frequencies have been shown that they are decreased with an increase in crack depth and an increase in the bamboo fiber weight. Thus, BGHC-2 made from 30% bamboo and 10% glass fiber can be a viable candidate for applications that will produce good vibration properties. Generally, the first-third natural frequency of the hybrid composite beam decreases within the increase of bamboo fiber and decreases in glass fiber. The composite materials having 60% of epoxy with 20% bamboo and 20% glass fiber, and 60% of epoxy with 10% glass and 30% bamboo fibers, are observed with a gradual decrease in the values of natural frequencies with respect to increasing in crack depth. A fine agreement was accomplished between the simulation and experimental results. Therefore, the present approach can be used to identify cracks for mechanical health monitoring by linking the variation in natural frequencies of the hybrid composite beams.

On the nonlinear dynamics and flutter response of hybrid shape memory alloy composite beams

This study presents a theoretical and numerical investigation of the dynamic response of a hybrid SMA composite beam. Particular emphasis is given to the evaluation of the equivalent damping, the aeroelastic stability, and the possibility to tune the composite’s dynamics by means of pre-strain applied locally to the SMA layers. The model of the hybrid composite beam (HCB) accounts for both the material nonlinearity associated with the phase transformation of the SMA and the geometric nonlinearity (in the von Kármán sense) due to potentially large displacements. The nonlinear governing equations of the HCB are solved by the finite element method and the dynamic behavior of the HCB is assessed for different design parameters, such as thickness, position, and pre-strain level of the SMA layers. Results help understand the role played by the different design parameters in improving the dynamic characteristics of the HCB, with particular attention to effective damping. Furthermore, it is of particular interest to understand the aeroelastic stability of hybrid layered composites due to their widespread applications in aerospace engineering. A simplified model of the nonlinear flutter response of the HCB under supersonic flow conditions is presented and analyzed with particular emphasis on bifurcations and limit cycle oscillations.

Effect of Delamination Size on the Natural Frequency of Twintex and Natural Fibre/Poly-Propylene Hybrid Composite Cantilever Beam

Effect of Delamination Size on the Natural Frequency of Twintex and Natural Fibre/Poly-Propylene Hybrid Composite Cantilever Beam

Vibration based damage detection for hybrid composite cantilever beam using finite element analysis and artificial neural network

Damage in mechanical structure causes a change in its physical properties and it will affect the real-time application. Cracks in a structure that distressed in model parameters like mode shape, and natural frequency. Its need to the identification of damage early to avoid catastrophic failure and increase the life of the mechanical structure. In this paper, a model for natural fundamental vibration analysis of cantilever beam with the inclined crack with different depths and different locations has been presented. The natural frequency of crack reduces by an increase in crack depth. The performances of results have been verified with finite element analyses software ANSYS, Experimental analysis and finally compare results with a neural network.

Flexural investigation of a composite trussed-beam for aerospace shelters using numerical modelling

The composite beams used in aerospace shelters are always exposed to many problems such as: expensive repairing and maintenance costs, and low durability. This research aims to investigate the effect of reinforcing hybrid composite beams with embedded steel-angle truss system (Trussed-beam) inside concrete cover to be used in aerospace structures and shelters. Foremost, a reliable finite element (FE) model was conducted to verify a previous experimental result of a trussed beam, using ABAQUS software. Then, a parametric study was conducted to optimize several parameters, using the reliable FE model. Six composite trussed-beam specimens were modelled to investigate the ultimate flexural capacity. Load-displacement curve was utilized to measure the flexural capacity of the beams. Based on the results obtained from the current study, the composite trussed beam, which is web reinforced by inclined steel Plates, with angle of inclination of 45 degrees obtained significant results relative to the traditional reinforced concrete beam. These hybrid composite beams’ flexural behaviour was significantly improved by increasing their compressive strength.

Nonlinear vibration of SMA hybrid composite beams actuated by embedded pre-stretched SMA wires with tension-bending coupling effect

Theoretical and numerical analyses for nonlinear vibrations of the shape memory alloy hybrid composite(SMAHC) beam actuated by the pre-stretched shape memory alloy(SMA) fibers with tension-bending coupling effect are presented in this paper. Under the sudden action of thermal temperature, a recovery force and moment are caused in the SMAHC beam due to the phase transition in the SMA fibers, exciting the nonlinear vibration of the SMAHC beam. The one-dimensional Brison constitutive model was adopted to express the influence of the phase transition temperature, initial volume fraction of martensite, and pre-strain on the phase transition in the shape memory alloy. On this basis, the constitutive law of the SMAHC beam is built by considering the tension-bending coupling effect and the phase transition in the SMAHC beam. The equation of motion for nonlinear vibration of the SMAHC beam with geometric nonlinearity and material nonlinearity is derived from the Hamilton principle and is discretized into matrix form using the Galerkin method. According to the algorithm of the NewMark-β method, numerical solutions are computed by developing Matlab program and are compared with the results from ABAQUS analysis. It shows that the frequencies and amplitudes of the theoretical calculations are very consistent with those obtained from ABAQUS analysis. In addition, both the theoretical study and ABAQUS simulation indicates that the high frequency for longitudinal vibration is not observed in the spectrum diagram of transverse vibration, while the low frequencies for transverse vibration are captured in the longitudinal vibration. With the established Matlab program, parametric study is carried out to investigate the effect of the temperature and the location of the SMA fibers on the vibration responses of the SMAHC beam. The results from this study indicate that the transverse vibration of SMAHC beams is characterized as one of low frequency, while the longitudinal vibration has the characteristics of high frequency. Especially in the case of nonlinear vibration, not only the vibration of high frequency but also the vibration of low frequency observed in the transverse vibration will occur in the longitudinal direction of the SMAHC beam. Furthermore, the double and triple fundamental frequencies of the transverse vibration are excited in the nonlinear vibration of the SMAHC beam. The results of this paper can provide a theoretical basis for the evaluation of the safety and stability of smart composite structures.

Nonlinear analysis of a bamboo plywood-steel composite I-section beam under bending

Bamboo is a promising “green” building material with mechanical and thermal properties of engineered bamboo products (EBPs) being competitive with engineered wood products. However, their structural connections are still a major concern and must be addressed comprehensively to extend their applications in low to mid-rise buildings. This study presents a nonlinear simulation of a laminated bamboo-steel hybrid composite I-section beam subjected to pure bending. Using a three-dimensional Finite Element (FE) analysis, the load-bearing capacity and deformation was investigated. First, an orthotropic constitutive relation of EBPs using Hill’s failure criterion is established and applied to the hybrid beam subjected to four-point bending. The model is built in ANSYS workbench and is validated with experimental results on the elastic material parameters of Moso bamboo. It is demonstrated that the computational model provides a prediction very close to the experiments with an average difference as low as 3%. The load–displacement curve obtained from the hybrid composite beam under flexure is also close to the experimental data. This good agreement is attributed to the incorporation of material, geometrical, and contact nonlinearities in the model.

Effect of lamina orientation, crack severity, and fillers on dynamic parameters of hybrid composite cantilever beam with double transverse cracks

AbstractModern‐day research in composite material development primarily focuses on tailoring combinations by proportions of constituent materials and monitoring the changes in their targeted properties. In line with this trend, a new class of glass fiber reinforced polymer hybrid composite beam of size 600 mm×50 mm×6 mm is fabricated by adding graphene (average particle size:10 μm), and flyash (average particle size: 60 μm). The dynamic behavior of the hybrid beam by introducing two transverse cracks at different positions with varying crack depths is studied by employing analytical, finite‐element, and experimental approaches. The dimensionless relative natural frequencies of the cracked/faulty hybrid beam obtained by the proposed methods are compared with the intact hybrid beam. Also, a comparison is made for the hybrid beam with a single crack. An increase in relative crack depth resulted in an increase in values of dimensionless compliances. Further, the effect of fiber orientation and lamina stacking sequence on the dynamic parameters of the hybrid beam are also analyzed. The introduction of the second crack induces higher nonlinearity in bending modes of vibration.

Buckling and dynamic behavior of uniform and tapered woven carbon/jute fiber reinforced polyester hybrid composite beams

In the current work, the dynamic and buckling properties of hybrid fiber-reinforced polymer composite beams are investigated. The hybrid composite beam is made of polyester matrix, carbon fiber, and jute fiber. The mechanical characteristics of carbon/jute/polyester composites were examined using ASTM standards. Experimental dynamic analysis was performed on jute, carbon, and hybrid carbon/jute composite beams. The validity of a finite element (FE) model based on higher-order theory was examined, and it exhibits outstanding agreement for composite beams when compared to experiments and literature. The hybrid composite beams have a considerable impact on structural stiffness when compared to neat jute/polyester composite beams. In this work, the effects of end conditions, taper angles, and composite layers are also investigated in relation to the dynamic and buckling properties of uniform and tapered hybrid carbon/jute/polyester composite beams. The findings imply that hybrid composites can be a superior substitute material for automotive applications.

Numerical validation and optimization of hybrid composite beam hull using multiple failure criteria

The number of structurally deficient bridges continues to increase due to corrosion of steel sections and concrete rebar, therefore the replacement of decaying structures and the development of innovative systems have become of high priority to extend the life span of newly built bridges. Hybrid Composite Beam (HCB) produced by Hillman is one of those systems that use a combination of materials i.e., concrete, steel, and Glass Fiber-Reinforced Polymer (GFRP) to integrate each main advantage in a single bridge beam structure. Despite its several apparent advantages; it is not widely spread as expected within the last decade. The HCB is manufactured of self-consolidating concrete (SCC), which is poured in the shape of a traditional arch and tied at its ends by high-strength tendons. A durable FRP composite hull encapsulates the SCC arch and the high-strength tying tendons in order to create a structural beam element for bridge applications. The HCB's design aims to provide pure compressive stresses to the concrete and pure tensile stresses to the steel. The current study performs a deep numerical investigation of the FRP hull instead of other components comprehensively studied. Numerical validation is performed for the deflection results on the experimentally tested Knickerbocker HCB Bridge, the deformations are validated at four stages of HCB manufacturing and testing. Further, the FRP hull strength ratios are quantified for the worst value of four failure criteria. The results showed an excess use of FRP material, where more than 90% of FRP areas have strength ratios of 5 to 50. The FRP hull thickness is minimized using Genetic Algorithm optimization under the worst case of loading. The results achieved more than 60% decrease in FRP weight, that led to only 20% cost difference between traditional precast concrete and HCB girders. It is finally concluded that the overdesign of FRP hull contributed to the high cost of HCB usage consequently inefficient market spread.

Effects of stirrup spacing on shear performance of hybrid composite beams produced by pultruded GFRP profile infilled with reinforced concrete

Effects of stirrup spacing on shear performance of hybrid composite beams produced by pultruded GFRP profile infilled with reinforced concrete

Thermal Buckling and Vibration Analysis of SMA Hybrid Composite Sandwich Beams

This work studies the buckling and free vibration behavior of Shape Memory Alloy Hybrid Composite (SMAHC) sandwich beams under a thermal environment. The sandwich beams consist of layers reinforced with SMAs and a FGM core, and they are simply supported at both ends. The higher order theory is combined with the Minimum Potential Energy principle or Hamilton principle to derive the governing equations of the thermal buckling and thermal vibration problems, respectively. The material properties of the beam are assumed as temperature-independent (TID) or temperature-dependent (TD). In the last case, two different types of thermal distribution are considered, namely a uniform and a linear distribution. The results based on the proposed formulation are verified against the reference literature, with a very good matching. A parametric study checks for the influence of different effective parameters such as thickness-to-length ratios, volume fraction powers, initial strain, volume fraction of SMA wires, and temperature distribution on the overall mechanical response of the selected structural member, with useful insights from a design standpoint.

Experimental investigation of the compressive strength of hybrid composite sandwich beams with double-corrugated sinusoidal core reinforced by graphene and polyurethane foam

In this paper, the effects of some system parameters such as nanographene, core geometry, and polyurethane foam on the compressive strength of composite sandwich beams with double corrugated lattice core subjected to flatwise-compression load are investigated experimentally. The face sheets and core of the sandwich beams are made of 10-layers bidirectional carbon fibers using the vacuum infusion process. According to the results of the flatwise-compression test, it was revealed that some factors, including height and angle of the core, the weight percentage of nanographene, and polyurethane foam, can be considered as effective parameters to enhance the compressive strength of the composite sandwich beams. Scanning electron microscopy images were utilized to observe the composition and distribution of the nanoparticles. It was observed that adding nanographene particles to the composite laminates significantly affects the mechanical properties and flexural strength of the sandwich beams. In addition, experimental results showed that the shape of the core can be an effective parameter to control the elasticity and strength of the sandwich beams, and also polyurethane foam dramatically increases the compressive strength and can postpone core failure.

Optimum Design of Fully Composite, Unstiffened, Built-Up, Hybrid Steel Girder Using GRG, NLR, and ANN Techniques

Composite steel beams are commonly used element in multistorey steel buildings to enhance floor economy and serviceability and provide more clear height. Due to the low level of stress in the webs of such beams, hybrid sections are used where the flanges have higher strength than the webs. A lot of earlier research was carried out to optimize the design of the hybrid and nonhybrid composite steel beams under both static loading and dynamic behavior. However, there is still a need to develop a more practical optimization method. The aim of this research is to develop simple and practical equations to determine the optimum cross section dimensions for both shored and unshored, simply supported, hybrid and nonhybrid, composite steel beam under static loads. To achieve that goal, a research program of two phases was carried out. The first phase was generating a database of 504 composite beams with different steel grades for flanges and webs, subjected to different values of bending moment. The cross section of each beam in the database was optimized using GRG technique to minimize the cost considering the unit price of each steel grade. In the second phase, the generated database was divided into training and validation subsets and used to develop two predictive models using Nonlinear Regression (NLR) technique and Artificial Neural Network (ANN) technique to predict the optimum cross section dimensions and hence the optimum weight and cost. The accuracies of the developed models were measured in terms of average error percent. NLR and ANN models showed average error percent of 16% and 11%, respectively.

Experimental Analysis of the Tensile Behavior of a Hybrid Composite Beam with Adjustable Mechanical Properties

Experimental Analysis of the Tensile Behavior of a Hybrid Composite Beam with Adjustable Mechanical Properties

Enhancing the properties of damar (Agathis loranthifolia Salisb.) wood by making hybrid bamboo-wood composite

This study was carried out to investigate the characteristics of laminated bamboo and damar (Agathis loranthifolia Salisb.) wood as the core layer of the bamboo-damar hybrid composite beam. Andong bamboo (Gigantochloa pseudoarundinacea (Steud.) Widjaja) and mayan bamboo (Gigantochloa robusta Kurz.) were used as the face and back layers of the beam, glued with isocyanate adhesive. Four types of composite beam were produced with various number of laminated bamboo layers. Results showed that the four layers (two layers for each face and back sides) laminated andong bamboo performed superior mechanical properties than others hybrid composite beam, while the four layers (two layers for each face and back sides) laminated mayan bamboo demonstrated the highest compression and bonding strength. The density, MOR, MOE and compression strength of the hybrid composite beam improved 31.3%, 25.95%, 37.81% and 25.12%, respectively, as the outcomes of the incorporation of laminated andong bamboo on the outer layers of the damar board. This paper proves that the number of laminated bamboo layers enhances the properties of the bamboo-damar hybrid composite beam. Furthermore, it shows promising result for complementing furniture and interior design materials as the bamboo-damar hybrid composite beam has remarkable properties.

A Comprehensive Review on Applicability of Shape Memory Alloy Hybrid Composite Beam in Vibration Control

Smart materials are used to construct smart structures, which can perform both sensing and actuation functions. Shape Memory Alloys are a kind of smart materials which can undergo solid-to-solid phase transformation and can recover completely when heated to a specific temperature. The Hybrid Composites that embedded with SMAs showing better results in vibration control. The trend in the aeronautical, mechanical and civil design requires lighter, stronger, and more flexible structures. However, light weight structures can be more easily influenced by unwanted vibrations, which may lead to the performance reduction, sometimes the system may even fail due to resonance, etc. This paper focuses on research work carried till now in the area of SMA hybrid composites and its applicability in vibration control.

Shear testing of reinforced hybrid composite beams made of SFRELC and partial higher-strength conventional concrete

Apart from the flexural performance of reinforced hybrid composite beams made of SFRELC (steel fiber reinforced expanded-shale lightweight concrete) and partial higher-strength conventional concrete, the shear properties are also essential to be understood for reliable application. To bridge this gap, sixteen reinforced hybrid composite beams compared with two reinforced SFRELC beams and two reinforced conventional concrete beams were experimentally studied under four-point test in this paper. The grades of SFRELC and partial conventional concrete were 40 MPa and 50 MPa respectively in cubic compressive strength. The composite depth ratio of conventional concrete to SFRELC varied from 0.3 to 0.5, the shear-span to depth ratio ranged from 1.5 to 3.0, and the volume fraction of steel fiber changed from 0.8% to 1.6%. The shear-cracking resistance, shear crack width, mid-span deflection and shear capacity of test beams were measured, and the crack distribution and failure modes were observed. Results indicate that the composition of SFRELC with higher-strength of conventional concrete confirmed a beneficial effect on the shear-cracking resistance and the shear capacity of reinforced hybrid composite beams. The interface of conventional concrete and SFRELC bonded well without any slip. The shear performance was slightly influenced by the composite depth ratio, and similar to reinforced SFRELC or conventional concrete beams with a varying of the shear-span to depth ratio and the volume fraction of steel fiber. Based on the test results, the tensile strength of SFRELC is used to predict the shear-cracking force of reinforced hybrid composite beams, while the equivalent tensile strength considering the combination of SFRELC and conventional concrete is used to calculate the shear capacity of reinforced hybrid composite beams. Finally, the design method is discussed for the shear capacity with the control of shear crack width of reinforced hybrid composite beams.

The effects of thermal loadings on wave propagation analysis of multi-scale hybrid composite beams

This research is concerned with the analysis of wave propagation of multi-scale hybrid composite beams subjected to various types of thermal loading. Carbon fiber (CF) and carbon nanotube (CNT) are assumed as reinforcements that are distributed in the matrix. The homogenization process is performed exerting the Halpin–Tsai model and the rule of mixture. Different types of temperature rise, namely, uniform, linear and sinusoidal temperature rise are presumed to present a more trustworthy thermal analysis. The beam is rested on Winkler–Pasternak foundation. A refined trigonometric shear deformable beam theory is used to compute the kinetic relations without any external shear correction coefficient. Governing equations are derived implementing Hamilton’s principle and then solved analytically. Eventually, the effects of different parameters, such as CNT’s weight fraction, the volume fraction of CF, elastic foundation, different types of temperature rise, etc., on wave frequency and phase velocity. are provided numerically in the framework of a set of illustrations.