Epoxy Matrix Material Research Articles

Microdroplet Pull-out Testing: Significance of Fiber Fracture Results

Fiber reinforced composites are used in structural materials that required light weight and stiffness. The properties of the fibers or matrix are important, but the interfacial properties have a significant impact on the properties of fiber reinforced composite. In this study, the interfacial shear strength (IFSS) was measured using acrylic resin and epoxy resin as base materials. The chemical composition of acrylic and epoxy matrix materials was analyzed to predict the effects on IFSS. Additionally, IFSS was measured through a microdroplet pull-out test. The reliability of the experimental results was enhanced by applying a statistical analysis to IFSS results. In the case of epoxy, GF/epoxy exhibited higher IFSS to twice and half times than CF/epoxy specimens. It means that the surface treatment of the fibers has a significant impact on the interface. In the case of acrylic, IFSS could be measured for GF. But in the case of CF, IFSS was too low to get accurate results of IFSS. Through this research, methods to improve the accuracy of composite interfacial strength measurement experiments were examined, and the study suggested the need for standardized criteria to evaluate composite interfacial adhesion.

Grafen nanoplatelet takviyeli epoksi kompozitlerin mekanik özellikleri ve aşınma davranışı üzerinde takviye oranının etkisi

New features are gained to the enhanced characteristic of composites with the addition of nanoscale particles. Graphene has an important place among nanoparticle reinforcing elements due to its two-dimensional structure and high strength. In this study, tribological behaviour and mechanical properties of the nano particle reinforced composite material investigated. The amount of nano particle reinforcement on the mechanical and wear behavior was investigated. Nanoparticles were incorporated into the non-reinforced sample at varying weight ratios, ranging from 0.1% to 0.5%. The findings indicated that the inclusion of graphene nanoparticles into the epoxy matrix material enhances the mechanical properties of the specimens across all reinforcement ratios.The failure load of the neat epoxy samples was determined as 415.94 N and the modulus of elasticity as 2.4 GPa. The best mechanical results in graphene reinforced composites were obtained in 0.2% reinforced composites, and the failure load and elasticity modulus values were found as 903.13 N and 4.46 GPa, respectively. Furthermore, the tribological performance of the specimens was examined under dry sliding conditions. The worn surfaces were examined using SEM. The incorporation of graphene reinforcement has been observed to positively impact the wear resistance of the epoxy matrix material.

Sound insulation performance of honeycomb core aluminum sandwich panels with flexible epoxy-based foam infill

The most distinctive features of sound insulation structures are their flexibility and porosity. Therefore, the flexible epoxy matrix material was made cellular using a suitable foaming agent. In addition, hollow glass microspheres (HGMs) were added to the epoxy matrix. Thus, the sound wave refraction was increased by obtaining cavities in the cell walls. Structures with different densities and voids were created by changing the ratios of the filling material and foaming agents used in the sandwich. An aluminum (Al) honeycomb was used to protect the insulation materials' structural integrity and ensure the homogeneous distribution of sound waves. The effect of density differences on sound insulation values was investigated. The mechanical properties of sandwich structures were determined using compression and three-point bending tests. The distribution of the filler in the matrix was visualized using SEM. TGA, DSC, thermal conductivity, dielectric, and flammability tests were also performed to determine their thermal, electrical, and flammability properties. During the formation of cells in the flexible epoxy, the HGMs were positioned in the cell wall by internal gas pressure. Low-density structures performed better at low frequencies, while high-density structures at high frequencies.

High-fidelity analytical modeling of asymmetric CFRP composites using Reissner–Mindlin theory and hygroscopic degradation

Multi-stable carbon fiber-reinforced composites with asymmetric ply layouts have shown promising potential for creating multi-functional structural systems. To design and analyze these complex composites, high-fidelity and computationally efficient analytical models are crucial. To this end, Hyer and Dano formulated the first model four decades ago based on classical lamination theory (CLT). Surprisingly, despite many follow-up studies to refine this analytical approach, current models still follow the same fundamental ingredients used in Hyer and Dano’s original work. As a result, they all inherited the same limitations. For example, they ignore the interlaminar stresses and lack a rigorously calibrated hygroscopic term. To overcome these limitations, we propose a new analytical modeling approach by adopting the Reissner–Mindlin theory and hygroscopic degradation. This new model introduces in-plane rotations as two additional degrees of freedom and a combined expansion coefficient for the epoxy matrix materials. Compared to finite element simulations and experiment data, the new model can estimate the interlaminar stress reasonably well (especially regarding its concentration near the edges) and predict the laminates’ external shape more accurately than an equivalent Hyer’s model. The new model can also accurately predict the reduction in the laminate’s curvature and snap-through force in different design configurations, as well as their linear correlation to the moisture content levels. Overall, the results of this study present a fundamental advancement in the analytical modeling of asymmetric multi-stable composite laminates, offering a broad and versatile foundation for designing and analyzing the next generation of multi-functional composite structures.

Non-linear buckling analysis of MWCNT reinforced hybrid composite shell subjected to hydrostatic pressure: A numerical and experimental investigation

The present study is focused on the numerical and experimental investigation of the non-linear buckling behavior and ply-failure analysis of a hybrid composite shell under uniform hydrostatic pressure exposed on its outer surface. Laminated composite shells made of glass fiber reinforced polymer (GFRP) composites with and without multi-walled carbon nanotubes (MWCNT) reinforcement are considered for the investigation. The critical buckling pressure is numerically determined by performing a buckling analysis on a hybrid composite shell with consideration of various non-linearities such as material non-linearity, geometric non-linearity, and geometric imperfection using the commercially available software ANSYS®. The governing non-linear differential equations of composite shell structures are solved using the arc-length approach and non-linear finite element analysis. The nanotubes dispersion, distribution, structural integrity, aspect ratio, functional group, and purity level of CNT reinforcement with epoxy matrix materials are quantified using field emission scanning electron microscopy (FE-SEM). The elastic and plastic properties of the GFRP lamina with and without MWCNT reinforcement are experimentally determined based on ASTM D3039. The critical buckling pressure obtained through experiments on a GFRP composite shell with and without MWCNT reinforcement is compared with the results obtained from the numerical analysis to validate the effectiveness of the present numerical model. Parametric studies are undertaken to investigate the first ply failure analysis, the effect CNT reinforcement, aspect ratio of MWCNT, and different lamination sequences on the critical buckling pressure of the composite shell. It was observed that the Von-Misses stresses developed on the composite structures with ply angles of either all layers as 0° or combination of ply angles with 0° and 90° is always less than those of the structures having ply-angles such as 45° and 60°, irrespective of CNTs reinforcement. Furthermore, the highest critical buckling pressure was obtained with reinforcement of 1.5 wt% MWCNT in the composite shell with ply orientation of [90°]4s.

Effect of Fiber Composition on Physical and Mechanical Properties of Turkey, Duck, Chicken Feather and Goat Hair Fiber Reinforced Polymer Composites

The natural fiber reinforced composites used in different industries such as aerospace, automotive, civil, chemical and medical are made good malleable properties. The animal fibers may be utilized as the reinforcement materials because it gives desired property at easier expense of generation. The present work focuses to evaluate and compare the mechanical properties of composites made from Animal Hair (Goat Hair) and Bird Feather (Turkey, Chicken and Duck Feathers) reinforced with Epoxy matrix material. Composites were fabricated at different percentage of fiber loading (3, 5 and 7 % by volume) by Hand layup process. The impact of loading different percentage volume of fiber on mechanical properties such as tensile strength and flexural strength were examined. Comparison has been made on the mechanical properties of the composites with different reinforcement. 5% chicken feather reinforced epoxy composites showed higher tensile and flexural test. Goat hair also acted as the better reinforcement in epoxy. Water absorption test was also conducted on the composites. From the result it has been identified that if the fiber content increases water absorption also increases. And chicken feathers show less absorption of water when compared with other composite

Influence of extraction methods on mechanical, absorption and morphological properties of water hyacinth (Eichhornia crassipes) natural fibre composites: Environmental threat to successive commercial products

The goal of this research is to identify different types of water hyacinth plant fibre extraction methods, and what effect each of those methods has on mechanical, absorption and morphological properties of water hyacinth fibre composites. The main objective of this study was to identify some new extraction techniques to efficiently remove the aquatic waste of water hyacinth plants, and convert this biological waste into some successful commercial products. The first method of extraction in our study was the conventional retting method, followed by a manual extraction method, a hot water extraction method and a chemical hot water boiling method. The extraction process is then carried out with the help of an automated machine using a bare motor. The aim of this project is to increase the mechanical strength of hyacinth fibre by producing large quantities of fibre and by finding an optimal fibre extraction process. In the process of compression moulding, the fibres obtained from different extraction methods are combined with an epoxy matrix material to produce polymer composite samples. The mechanical strength, hardness and surface morphologies of the differently extracted water hyacinth fibre-reinforced composite samples are analysed in this work.

Use of discarded carpet material in the development of polymer (epoxy) composites for structural functions

The solid waste generated through the carpet and textile industry produces pollution and health risks in various forms when discharged into the open space. This study aims to utilize post-consumer discarded carpets for the manufacturing of lightweight polymer composites. The waste generated from the carpet industry has been a matter of serious concern for the environment. The average life of a carpet is approximate 8-9 years. After that becomes a non-biodegradable waste that is hazardous for the environment and occupies large landfill areas. In this context, the carpet waste is used to enhance the structural properties of the polymer (epoxy) composite. The epoxy is modified using waste carpet in two separate configurations: back-fiber-fiber-back (BFFB) and fiber-back- back-fiber (FBBF). A modified Vacuum-assisted resin transfer molding (VARTM) has been used to infuse the mixture (epoxy and hardener) into the waste carpet samples. The tensile, compressive, and flexural strength tests of the proposed samples were performed to analyze the mechanical behavior. The Scanning electron microscopy (SEM) outcomes demonstrate a good bonding strength between the epoxy matrix and filler material fabric (waste carpet). The FBBF configuration has comparatively superior mechanical performance than the BFFB. The mechanical testing results indicate that the developed samples can be satisfactorily used for lightweight structural applications such as sound barriers, wall tiles, desk boards, toys components, decorative product parts, etc. The research demonstrates that polymer composite reinforced by carpet waste can be endorsed as an acceptable and cost-effective replacement of structural polymer components. Also, the proposed method is remarked as a feasible solution to utilize the waste carpet into end products.

Utilizing the aquatic waste and investigation on water hyacinth (Eichhornia crassipes) natural plant in to the fibre composite: Waste recycling

Nowadays, natural fibres are mostly used as reinforcement material instead of using synthetic fibre because of their environmentally friendly characteristics. Water hyacinth is a free-floating aquatic plant mainly available in local water bodies. This plant gains the very fastest-growing characteristics compare to other aquatic plants. This plant fibre is extracted by utilizing the Mechanical extraction machine from the WH stem. After the extraction of fibre then the WH dried stem is converted into hyacinth powder and ash particles. With the mixing of the epoxy matrix material to the hyacinth fibre reinforcement WH composite is produced. The mechanical strength of WH fibre composite varies from 18.28 to 23.46 MPa on tensile, 26.52 to 45.6 MPa on flexural, and 0.10 to 0.5 J with respective plate thickness on impact strength. Based on water and chemical absorption studies the hyacinth composite absorbs only 2.5% of the water and chemical contents. Throughout this paper water, hyacinth fibre composites' mechanical strengths and surface morphologies are studies. These composite surfaces are examined with the help of an optical microscope. Finally, hyacinth fibre composite attains more strength compare to powder and ash composites. In conclusion novel, hyacinth composite is the better alternative to use conventional natural fibres on economic aspects and waste management approach.

Graphene as a stimulus for mechanical strength in glass-fiber reinforced polymers composite

PurposeThe purpose of this paper is related with the comparative study between graphene-based glass fiber–reinforced polymer composites and without graphene composite on polymer matrix. The current study explains the result of amalgamation of 4 Wt.% graphene oxide (GO), in comparison to without graphene, on the mechanical strength of glass fiber/epoxy (GE).Design/methodology/approachA hand layup technique is used for the experimental study. For this, chemical synthesis process is approached based on Hummer’s theory. For mechanical testing of glass fiber–reinforced graphene composites and without graphene composites, American Society for Testing and Materials-3039 (ASTM3039) standards was adopted. Furthermore, comparatively, composites were characterized by field emission scanning electron microscopy.FindingsReinforcement of 4.0 Wt.% GO in epoxy matrix material showed 7.46% and 12.31% improvement in mechanical strength and elongation, respectively. Scanning electron microscopy results showed the influence of graphene cumulations in the failure of GO-reinforced GE (GO-GE) composites.Originality/valueThe inimitable things of graphene grounded nanofillers have encouraged in the world of material for their thinkable manipulation in glass fiber polymeric composites. In this work, for the first time, graphene is used as nanofiller in glass fiber epoxy coatings, and their fractography study is investigated.

Structural optimization of a composite launch tube of man portable air defense system

PurposeThe purpose of this paper is to find the optimum configuration of the composite launch tube currently being developed in Roketsan. The winding thicknesses and winding angles of the launch tube are selected as design variables, and three different composite material alternatives are evaluated: glass/epoxy, carbon/epoxy and aramid/epoxy.Design/methodology/approachIn this study, structural optimization of a composite launch tube of man portable air defense system is conducted. To achieve a cost-effective design, a cost scoring table that includes structural weight, material cost, availability and manufacturability is first introduced. Then, optimization for minimum weight is conducted, where the winding thicknesses and winding angle are taken as design variables, and the safety factor value obtained by using the Tsai–Wu damage criterion is used as constraint. A surrogate-based optimization approach is used where various options for surrogate models are evaluated. Glass/epoxy, carbon/epoxy and aramid/epoxy are considered as alternative materials for the launch tube. Finally, the selection of the most cost-effective design is performed to achieve optimum cost.FindingsCarbon fiber-reinforced epoxy matrix material provides the optimum cost-effective design for the launch tube.Practical implicationsThe findings of the paper can be used to design more cost-efficient composite launch tube currently being developed in Roketsan.Originality/valueThe existing studies are based on a design approach to achieve minimum weight of the launch tubes, whereas this study introduces a design approach to achieve optimum cost.

Analysing the effect of mechanical properties of various proportions of filler material on jute fibre/epoxy reinforced composites

In the earlier stage of 1500 BC’S composites were invented. The initial stage of composites was created with the help of mixing the mud and straw for construction purpose, in order to build strong and durable component in the view, to ensure the longer life on the products. After some years, the usage of composite materials is become more, depends on different applications such as appliances, construction, electrical distribution, energy and marine usages and so on. Since the past few decades’ natural fibres plays a vital role in structural applications such as ease of fabrication, low cost, high durability, and for low thermal properties. In the present experimental investigation work, jute fiber has been chosen as the reinforcement agent along with the epoxy matrix material. With help of the hand layup technique the composites have been fabricated along with the standard ratio of (3% & 6%) calcium carbonate as the filler material. The fabricated jute fiber reinforced epoxy matrix (standard ratio of calcium carbonate filler) laminate were cut as per the ASTM standards to do the tests like tensile, flexural & impact, in order to completely analyse the physical strengths of the laminate, and the same data’s were compared with filler materials and without filler material. At last the fractured surfaces were thoroughly investigated with help of scanning electron microscope to understand the morphological behaviour of the fabricated composite.

Effect of cascara/testa natural fiber reinforced (epoxy based) hybrid composites

In this investigation, cascara/testa has been chosen as the particulate reinforcement agent along with the E-Glass fiber support, upon the epoxy matrix material. To carry out the experimental analysis, the standard ratio of cascara, testa and combinations of both have been selected as the particulate reinforcement, as 10% weight ratio of each respectively. Moreover to completely exploit mechanical behaviourism of the fabricated composite, physical analysis like tensile, flexural, impact and water absorption tests have been conducted as per the ASTM standards. In the pretext of the analysis, the strain rate of the tensile and flexural analysis has shown the increase of 3.5% and 2.75% respectively. In the same way, the impact analysis has also shown the hike in the absorption value as 1.25%, 1.12%. Furthermore the obtained results have shown that, the addition of cascara/testa have considerably increases the strain value and impact resistance of the fabricated specimens in sizeable manner by compromising the water uptake behaviour. Out of all standard tests, the hybrid composites (combination of cascara and testa) have shown the good conformity with all set of remaining specimens.

Mechanical Characteristics and Adhesion of Glass-Kevlar Hybrid Composites by Applying Different Ratios of Epoxy in Lamination

Hybrid composites have great potential for specific strength and specific stiffness, effective in aerospace industries, submarines, and light-weight automotives. The mechanical strength and adhesiveness of hybrid laminates can be enhanced by effective use of matrix materials in different ratios of epoxy resin and epoxy hardener. Gentle use of resin and hardener in the fabrication of hybrid composites can alter tensile modulus, the bonding strength between matrix and fabric. Spectacular progress has been achieved by the selection of appropriate amounts of resin and hardener in the hybridization of composite laminate. Hybridization was made by Kevlar inorganic/organic fabrics and glass fabrics stacked with epoxy matrix material. To achieve the combination of mechanical properties and bonding strength, transparent epoxy resin and hardener of commercial grades mixed in various ratios are incorporated as matrix material to fabricate laminate. Three different sheets, named A (3:2), B (4:1), and C (2:3), were embedded by the hand layup method to prepare a hybrid composite. Experimental tests, according to ASTM 3039, were performed to determine the tensile mechanical properties. Peel tests, according to ASTM 6862-11, were performed to investigate the interlaminar strength between Kevlar and glass layers. Shore A and Shore C hardness durometers were used to find out the hardness of the specimens at different spots using the ASTM D-2240 standard. Finally, physical testing, such as density and then water absorption, was carried out using the ASTM D-570 standard to check the swelling ratio of the different specimens. The results obtained highlight that the specimen of the glass/Kevlar hybrid embedded in the ratio 3:2 in lamination has the best mechanical properties (tensile strength and hardness) and the lowest swelling ratio, while the material system in the ratio 4:1 shows the best interlaminar properties and adhesion capabilities.

An experimental investigation of the effect of natural fiber treatment and marine environment on Cannabis Sativa/epoxy laminates

Materials have helped in evolving technology to a great extent. Composites have replaced conventional metals/ non-metals because of their lightweight. Natural Fibers have been need of the hour owing to environmental concerns and ease of availability. In this work, Cannabis Sativa fibers were treated with 5% Potassium Hydroxide solution. The laminates were prepared by the Compression Moulding technique by reinforcing treated and untreated fibers with an epoxy matrix material. To access the durability of natural fiber composites in the marine environment, prepared laminates were aged in seawater for 150 days. Tensile, flexural and moisture absorption behavior tests have been performed to estimate the durability in seawater. The data obtained have been compared with pristine treated and untreated fiber reinforced samples. From the results, it has been observed that tensile and flexural behavior of untreated fiber reinforced composites were superior to a treated counterpart in both pristine and aged conditions.

Studies on Dry Sliding Wear and Solid Particle Erosive Wear Behaviours of Natural Fibre Composite Developed from Water Hyacinth Aquatic Plant for Automotive Application

In this research, an attempt is made to investigate the abrasive and erosion wear resistance of aquatic waste plant water hyacinth converted fibre‐reinforced polymer composites. From a novel approach, the new fibre extraction machine is designed to extract the hyacinth fibre from the parent plant and reinforce it to the epoxy matrix material to produce a natural fibre composite for frictional applications. The extracted fibre is dried in the open sunlight area for 22 to 35 days to remove moisture and external dust particles. Then, different weight percentages (15, 20, 25, 30, and 35) of composite samples are produced with the help of the hot press compression moulding technique. Improved hyacinth composite tribology properties are tested by utilizing the pin on the disk machine. This setup included various processing parameters like load (10, 20, and 30 N), velocities (1, 2, and 3 m/s), speed (160, 320, and 479 rpm), and constant sliding distance condition, and the erosion setup also influences the essential parameters like impact angle (30, 45, and 60°), erodent velocity (1, 2.5, and 3.3 m/s), and discharge rate (28, 41, and 72 g/m). The factorial techniques are used to identify the important design factors. The final results represent the weight loss, volume loss, and erosion rate of hyacinth fibre composite. By utilizing the SEM (scanning electron microscope), the worn surface morphology of different weight percentages of hyacinth fibre samples are analysed. To upgrade the usage of hyacinth reinforced composites for different industrial applications, wear and erosion studies are conducted with different parameter conditions.

Experimental investigation on the mechanical properties of aluminium sandwiched sisal/kenaf/aloevera/jute/flax natural fibre-reinforced epoxy LY556/GY250 composites

In engineering, composites have indicated a more profound influence in the recent development of materials with high strength to weight ratio. The purpose of this work is to identify the different and specific properties which a composite possesses when various reinforcement fibres are used in different epoxy matrix material. Composite materials have a major role to play with meeting that requirement. Many natural fibre composite materials possess good mechanical properties but still lack in satisfying applications requirements and alternate for which is seen as sandwich natural fibre composites. In this investigation, an effort has been made to study the mechanical properties exhibited by sandwich epoxy composite reinforced with various commonly used natural fibres, namely Aloevera, Kenaf, Sisal, Jute and Flax. The polymer resin used as matrix is also varied using Epoxy LY556 and Epoxy GY250. The originality of this work is in the use of Epoxy GY250 to fabricate sandwich composites with five commonly available natural fibres and compare its performance to the more widely used Epoxy LY556. It has been determined through various mechanical tests, which particular epoxy resin bonds better with the natural fibres namely, jute, sisal, aloe vera, kenaf and flax thereby providing better tensile, impact and flexural properties. The investigation is hoped to provide an insight into how the environmentally friendly natural fibres interact with the varying matrix resins and how this interaction affects the mechanical properties of said composites.

Modulation of impact energy dissipation in biomimetic helicoidal composites

Biologically composites offer inspiration for the design of next generation structural materials due to their hierarchical microstructure that allows for, low density, and combination of high stiffness and toughness, currently unmatched by engineering technologies. Here, we investigate biomimetic composite materials that feature the laminated helicoidal architecture of fibers characteristic of the arthropod cuticle, specific to the mantis shrimp, but utilize either glass or Kevlar fibers, with epoxy or urethane matrix materials, to examine their role in impact energy dissipation. Drop weight impact test revealed epoxy-matrix composites exhibited the highest peak load on impact and showed larger degrees of external damage such as delamination and fiber breakage as compared to the urethane-based composites. Moreover, the helicoidal panels, showed a significant reduction in dent depth and better residual compressive strength as compared to the quasi-isotropic design. These findings provide useful insight into the variation of reinforcement and matrix materials for the helicoidal architecture and how it affects the delocalization of damage and improves residual strength.

Failure mechanism analysis of fiber-reinforced polymer composites based on multi-scale fracture plane angles

This paper proposes a physically sound elasto-plastic damage constitutive model, through following Mohr's fracture hypothesis, to characterize pressure sensitivity, nonlinear behaviors and isotropic damage of epoxy matrix materials. Upon the consideration with geometric non-uniformities and mechanical behaviors of constituents, a micromechanical analysis is carried out to study failure mechanisms within fiber-reinforced polymer composite materials applied by different loading scenarios. In particular, special focus is given to the values and distributions of fracture plane angles on multi-scales - the fiber scale and the lamina scale, and therefore both damage scenarios and dominant failure mechanisms are further revealed. The influence of shear nonlinearity of epoxy matrix on overall composite shear responses is assessed from a parametrical study, showing that the composite response induced by longitudinal shear is more susceptible the matrix shear property, when comparing with transverse shear. At last, another use of the proposed micromechanical model is presented. With the use of strength properties and fracture angles captured by micromechanics, the parameters (R⊥At, p⊥⊥t and p⊥⊥c) in Puck's criterion can be computed without making any assumption sometimes arguable. In general, the numerical results regarding homogenized stress-strain responses as well as fracture morphology agree well with experimental measurements and theoretical analyses, validating the predictive capacity of the proposed model.

Piezoelectric energy harvesting using macro fiber composite patches

Over the last decade, vibration energy harvesting has received substantial attention of many researchers. Piezoelectric materials are able to capture energy from ambient vibration and convert it into electricity which can be stored in batteries or utilized to power small electronic devices. In order to benefit from the 33-mode of the piezoelectric effect, interdigitated electrodes have been utilized in the design of macro fiber composites which are made of piezoelectric fibers of square cross sections embedded into an epoxy matrix material. This paper presents an analytical model of a macro fiber composite bimorph energy harvester using the 33-mode. The mixing rule is applied to determine the equivalent and homogenized properties of the macro fiber composite structures. The electromechanical properties of a representative volume element composed of piezoelectric fibers and an epoxy matrix between two successive interdigitated electrodes are coupled with the overall electro-elastodynamics of the harvester utilizing the Euler–Bernoulli theory. Macro fiber composite bimorph cantilevers with diverse widths are simulated for power generation when a resistive shunt loading is applied. Stress components in the Kapton layers, which are typically a part of any macro fiber composite patch, and in the bonding layers have been included in the model contrary to previously published studies. Variable tip mass, attached at the free end of the beam, is utilized in this paper to tune the resonance frequency of the harvester. The generated power at the fundamental short circuit and open circuit resonance frequencies of harvesters having three different widths is analyzed. It has been observed that higher electrical outputs are produced by the wider macro fiber composite bimorph using (M8528-P1 patches).