Mechanical Properties Of Composite Materials Research Articles

Forward and inverse design of kirigami via supervised autoencoder

Machine learning (ML) methods have recently been used as forward solvers to predict the mechanical properties of composite materials. Here, we use a supervised-autoencoder (sAE) to perform inverse design of graphene kirigami, where predicting the ultimate stress or strain under tensile loading is known to be difficult due to nonlinear effects arising from the out-of-plane buckling. Unlike the standard autoencoder, our sAE is able not only to reconstruct cut configurations but also to predict mechanical properties of graphene kirigami and classify the kirigami witheither parallel or orthogonal cuts. By interpolating in the latent space of kirigami structures, the sAE is able to generate novel designs that mix parallel and orthogonal cuts, despite being trained independently on parallel or orthogonal cuts. Our method allows us to both identify novel designs and predict, with reasonable accuracy, their mechanical properties, which is crucial for expanding the search space for materials design.

Influence of Sodium Hydroxide (NaOH) Treatment on Mechanical Properties and Morphological Behaviour of Phoenix sp. Fiber/Epoxy Composites

The purpose of this present research work is to assess the static and dynamic mechanical properties of an eco-friendly natural cellulosic fiber (Phoenix sp.) reinforced epoxy composites. The cellulosic fiber was isolated from Phoenix sp. plant petioles, and it was treated with various concentrations of sodium hydroxide (5, 10, 15 and 20%) solution. The impact of treatments on tensile, flexural, impact and dynamic mechanical properties of the fabricated composite was explored and optimized. Moreover, the mechanically tested samples were subjected to morphological analysis to predict the failure mechanisms. The outcomes revealed that the treated fibers had good interfacial bonding with epoxy matrix (confirmed through morphological and single fiber pull-out studies), reduced the failure mechanisms (fiber pull-outs and fiber debonding) and exhibited good static and dynamic mechanical properties of composite materials than untreated fiber composites. It is concluded that composites fabricated using 15% of sodium hydroxide treated fiber could be used to manufacture automotive panels and other lightweight industrial products.

Comparative Analysis Of Mechanical Properties Of Rubber-Kenaf-Wire-Cotton Lamination On Epoxy-Carbon-Ramie Composite

The use of fiber has been widely researched but the use of several fibers as reinforcement does not necessarily result in optimal mechanical properties. This study aimed to determine the tensile strength and impact strength of composite materials using an epoxy matrix with the addition of rubber variations to increase the ductility of the matrix. Meanwhile, the fibers used for reinforcement are carbon fiber and ramie. In this study, the reinforcement added a variety of kenaf fiber, wire and cotton. This was to compare the role of kenaf fiber, wire and cotton in improving the mechanical properties of composite materials. The percentage of rubber volume fraction added to the epoxy is 30%, 40% and 50%.The highest tensile test results were shown in the 30% epoxy rubber-carbon fiber-ramie fiber-kenaf specimen which was 10.67 Kgf / mm2, and the lowest result was the epoxy 50% rubber-carbon fiber-ramie-wire specimen, which was 5.752 kgf / mm2. The fracture analysis of the tensile test showed that the fracture area is formed by debonding phenomena between fibers and matrices.The highest impact strength was found in the 50% epoxy rubber-carbon fiber-ramie-wire specimen, which was 0.039 kgf / mm2. Meanwhile, the lowest impact strength was found in the 40% epoxy rubber-carbon fiber-ramie fiber-cotton specimen, which was 0.030 kgf/ mm2. In general, the trend of impact test data shows that as the percentage volume fraction of rubber increases, the impact strength of the composite material increases.Based on the test analysis, it was concluded that increasing the percentage of rubber will increase the impact strength of the woven wire reinforcement. However, the impact strength is inversely proportional to kenaf fiber reinforcement, where the addition of the percentage of rubber will reduce the impact strength. This showed that the mechanical properties were not always influenced by the percentage of rubber but were very dependent on the type of fiber. This was also shown in the results of the tensile strength test. In general, it was known that the adhesion between fiber and matrix laminates affected the mechanical properties in addition to the strength of the reinforcement.

Simulation and Optimization of a CFRP and a GFRP floating pontoon

According to the unique mechanical properties of composite materials, the replacement of the conventional materials like steel with composite materials is increasing in all fields. The low weight / capacity characteristics of composite materials make it possible to accommodate much more loads. Because of the great importance of the floating bridges for both military and civilian purposes especially in crises, the evolution of floating bridges is necessary. The traditional transportation steel ferry is composed of floating steel pontoons to accommodate the MLC-70 (Tank load) of weight equals (63.5 t). In this study, the steel floating pontoon is replaced with composite pontoon simulated for both carbon fibres polymers and glass fibres polymers with the laminate configuration . The finite element analysis is performed using ANSYS software. The capacity of the ferry is increased to reach (90 t) instead of (70 t). The total deformation is determined under the applied load. The failure criteria is investigated for both composite models (Tsai-Wu, Tsai-Hill, maximum stress and maximum strain). The nonlinear buckling analysis is also, investigated. The optimization process is designed and performed to get the optimum number of layers and angles orientation of the composite layers as well as possible.

Utilization of grey Taguchi method to optimize the mechanical properties of hemp and coconut shell powder hybrid composites under liquid nitrogen conditions

Through this work an attempt was made to improve the mechanical properties of composite materials by using a process called Gray-Taguchi. Hand lay-up approach has been adopted for manufacturing. Here, Woven Hemp fiber diameter, Number of hemp layer, coconut shell powder content and cryogenic temperature ranges at different levels were incorporated as result parameter. ASTM specifications were set for the manufactured laminates to perform the mechanical tests. Hemp and coconut shell powder material are exposed to 5 percent NaOH treatment to create the matrix-fiber interface exchange. To optimize composite, the Taguchi method is combined with the Gray relational analysis. The quality targets are set for mechanical properties that include compressive strength, tensile strength, impact strength and flexural strength. This study involved nine experiments on the orthogonal array of the L9 (34) Taguchi method. A combination of the composite, Gray relational analysis was applied to obtain the optimal parameter. The results of optimum parameters were verified using Conformation test. The maximum prescribed parameters are 0.7 mm woven hemp diameter, two hemp layers, 10 percent CSP content weight, and -130°C cryogenic temperature range provides the maximum energy of impact, tensile strength and flexural strength.

PROBLEMS AND PROSPECTS OF COMPUTER DESIGN OF NEW COMPOSITE MATERIALS

Problems arising when analyzing the physical and mechanical properties of composite materials based on polymer matrices are under study. The structural features of such materials and the resulting difficulties in the development and implementation of corresponding models are discussed. A technique for determining the effective strain-strength, thermophysical, and electrophysical properties of the compositions is proposed, and a number of examples are considered. Particular attention is paid to solving computer design problems in order to determine the composition and structure of composites under specified constraints on their effective properties. Initial data for solving these problems are obtained both in field and computational experiments. Directions for further research are identified.

Mechanical and tribological behaviour of AZ91/ZrSiO4 composites

In this present experimental work, magnesium matrix composites (MMCs) were manufactured by stir casting method. Magnesium is a metal which is more abundant and has very less density but the problems is it has better wear resistance and low hardness. To improve the properties of magnesium, ZrSiO4 ceramic powder are reinforced. The tribological and mechanical properties of composite materials were investigated. The effects of reinforcement on the mechanical properties of the composites were investigated by 0, 4 and 8 wt% of ZrSiO4 ceramic powder with a size of 40–60 µm. The primary aim is to investigate the mechanical and tribological behaviour of AZ91/ZrSiO4 composites. ZrSiO4 powders are added at required proportions to produce magnesium alloy (AZ91) matrix composites. AZ91 along with ZrSiO4 confirms fine mechanical properties. The demand of magnesium matrix composites has increased mainly due to its high specific strength, better damping properties, excellent cast ability and superior machining ability.

A Study of Some Mechanical Properties of Composite Materials with a Dammar-Based Hybrid Matrix and Reinforced by Waste Paper.

When obtaining environment-friendly hybrid resins made of a blend of Dammar natural resin, in a prevailing volume ratio, with epoxy resin, it is challenging to find alternatives for synthetic resins. Composite materials reinforced with waste paper and matrix made of epoxy resin or hybrid resin with a volume ratio of 60%, 70% and 80% Dammar were studied. All samples obtained have been submitted to tensile tests and Scanning Electron Microscopy (SEM) analysis. The tensile response, tensile strength, modulus of elasticity, elongation at break and the analysis of the fracture surface were determined. The damping properties of vibrations of bars in hybrid resins and in the composite materials under study were also examined. The mechanical properties of the four types of resins and of the composite materials were compared. The chemical composition for a hybrid resin specimen were obtained using the Fourier Transformed Infrared Spectroscopy (FTIR) and Energy, Dispersive X-ray Spectrometry (EDS) analyzes.

A Study of the Mechanical Properties of Composite Materials with a Dammar-Based Hybrid Matrix and Two Types of Flax Fabric Reinforcement.

The need to protect the environment has generated, in the past decade, a competition at the producers’ level to use, as much as possible, natural materials, which are biodegradable and compostable. This trend and the composite materials have undergone a spectacular development of the natural components. Starting from these tendencies we have made and studied from the point of view of mechanical and chemical properties composite materials with three types of hybrid matrix based on the Dammar natural hybrid resin and two types of reinforcers made of flax fabric. We have researched the mechanical properties of these composite materials based on their tensile strength and vibration behavior, respectively. We have determined the characteristic curves, elasticity modulus, tensile strength, elongation at break, specific frequency and damping factor. Using SEM (Scanning Electron Microscopy) analysis we have obtained images of the breaking area for each sample that underwent a tensile test and, by applying FTIR (Fourier Transform Infrared Spectroscopy) and EDS (Energy Dispersive Spectroscopy) analyzes, we have determined the spectrum bands and the chemical composition diagram of the samples taken from the hybrid resins used as a matrix for the composite materials under study. Based on the results, we have suggested that these composite materials could be used in different fields of activity.

Investigating the effect of the aging process on LDPE composites with UV protective additives

The contact with ultraviolet rays coming from sunlight causes color changes and deterioration in the main chain structures of composites in outdoor applications and affects the physical and mechanical properties of composite materials negatively. Photodegradation can be slowed and the mechanical strength of composite structures can be improved with adding photostabilizers in polymer matrix production. In this study, we modified low-density polyethylene (LDPE) polymer with an amine light stabilizer (Chimassorb 944), a light absorbent (Tinuvin 326), and an antioxidant (Irganox 1010) and then reinforced with jute fabric (JF). We examined the effect of protective additives, which are used to reduce the harmful effects of sunlight, on JF-reinforced LDPE composites. The color change, physical, and mechanical properties of the composites were determined after 120- and 240-h accelerated aging processes. The results indicate that both the antioxidants and the amine light stabilizers were more effective photostabilizers for JF-reinforced LDPE composites than the absorbents.

Statistical Analysis of CFRP Mechanical Properties using B-Basis Based on Weibull and ANOVA Distribution Analysis

In this paper, the mechanical properties of composite materials are subjected to statistical analysis. This study aimed to determine the value of B-Basis strength parameters of carbon composite material with UD-00, UD-900, fabric-00, fabric-900 from the results of tensile and compression tests. The maximum normal residual test was used for outlier identification and k-sample Anderson’s darling test to determine whether parameters can be processed as one large group of data. The scope of this study focused on evaluating B-Basis values using two methods: Weibull and ANOVA. The results showed that Weibull distribution method could be applied to analysis the data and produced a confidence level of 95%. ANOVA method however, could not be applied to specific data which were the tensile strength of UD 00 with a non-tabbing treatment. This was due to the inhomogeneous of the data.

Numerical and Experimental Analysis of Stacking Sequences Effects in Composite Mechanical Joints under Impact Loadings

Composite structures in the field of advanced and modern structures in engineering design and according to high specification of composite materials such as high strength to weight ratio use in various industries such as aerospace, marine. One of the most important fields that Researchers have paid less attention to that is to investigate the effect of stacking sequence on the strength of mechanical joints under impact loading. In view of changing the mechanical properties of composite materials by changing the arrangement of layers, in this study, the effect of different orientation of layers on the strength of pin joints in glass-epoxy composites under low-velocity tensile impact has been investigated. Using the Abaqus software and the finite element method, the impact simulation and the force applied to the mechanical joint were analyzed. To evaluate the simulations, the results of the finite element method have been compared with the experimental results. By observing the results, the introduced finite element model is well-considered and is well-matched with the result of the experimental dataset, which made it a valuable tool for predicting the strength of multi-layer composite materials under impact loadings. Using the results of the model, one can analyze the distribution and type of stress and strain in each layer of composite.

Stochastic Second-Order Two-Scale Method for Predicting the Mechanical Properties of Composite Materials with Random Interpenetrating Phase

Stochastic Second-Order Two-Scale Method for Predicting the Mechanical Properties of Composite Materials with Random Interpenetrating Phase

Influence of Rubber Particle Size on Functional Properties of a Composite Material Based on Scrap Tires and a Polymer Binder

Functional properties of composite material based on mechanically grinded scrap tires with different particle size of fractioned crumb and polyurethane type polymer binder were investigated to estimate influence of rubber particles size and content on composite material properties (Shore C hardness, compressive stress at 10 % deformation, tensile strength, elastic modulus and elongation at break, apparent density). Optimization possibilities of composite material consisting of rubber particles with different sizes or fractions were investigated. The obtained results show that variation of composition of the composite material by changing size of rubber granulate have definite influence on selected properties of the material. Purposeful selection and mutual combination of rubber particles size included in material can ensure desirable and predictable mechanical properties of composite material.

Oriented granulometry to quantify fibre orientation distributions in synthetic and plant fibre composite preforms

Fibre orientation is an essential factor governing the mechanical properties of composite materials. This study proposes an original method based on gray-level granulometry to analyse the fibre orientation distribution (FOD) of synthetic and natural fibre reinforcements aiming composite applications. An orientation maps is computed from SEM images and frequency of fibre orientation is graphically illustrated for each angular direction. First, glass fibre nonwoven and unidirectional preforms were analysed as a model to validate the method before testing their flax fibre counterparts. Differences in structural organisations were found between flax and glass fibre reinforcement FOD due to the specific structure and mechanical behaviour of plant fibres but also to the preform manufacturing process. Promising results were obtained confirming the reliability of this novel numerical method for fibre orientation determination.

Analysis of Mechanical Properties of Composite Materials with Nano Particles by using Feathers

Analysis of Mechanical Properties of Composite Materials with Nano Particles by using Feathers

Research of mechanical properties of composite material based on titanium nickelide with a titanium surface layer depending on magnetron sputtering time

The regularities of the titanium surface and transitional monolayers formation using magnetron sputtering and ion bombardment depending on the deposition time, adhesion parameters and mechanical characteristics are investigated. Saturation regions of the surface and transition layers are noted. The transition layer provides high adhesion of the surface layer to the substrate. The application of a titanium surface layer to a nitinol reduces elongation and yield strength but increases tensile strength, and as the deposition time increases, the elongation decreases very slightly, and the yield strength and strength increase.

Physical and mechanical properties of composite materials in the MoSia2-SiC-TiB2 system

In this work, we obtained ceramic materials based on MoSi2, hardened by SiC and TiB2 particles, which makes it possible to increase the heat resistance of the composite and increase the level of its physical and mechanical properties (at a relative density of more than 99, 0 %, tensile strength in bending 520 ± 10 MPa). The shrinkage, density, porosity and weight loss of composite materials during sintering were studied. The value of the ultimate strength in bending of materials at the optimum sintering temperature is determined. The maximum values of physical and mechanical properties are achieved for a material composition of 50, 0 vol. % MoSi2 + 15, 0 vol. % SiC + 35, 0 vol. % TiB2: E = 471 ± 10 GPa; σb = 520 ± 10 MPa, K1C = 4, 4 ± 0.1 MPa • m1/2; HV = 22.1 ± 0.1 GPa obtained at a sintering temperature of 1950 ° C.

The Research of Physical and Mechanical, Thermophysical Properties of Epoxy-Polyester Composite Materials Filled with Discrete Fibers to Increase the Reliability of Vehicles

In the article the polymeric materials based on epoxy-polyester binder with addition of dispersed fibers were developed. The mechanical and thermophysical methods were used. The influence of carbon fibers (0.01–0.30 pts.wt.) and cotton (0.01–0.30 pts.wt.) on the physical and mechanical, thermophysical properties of epoxy-polyester composites was investigated. The results of the experiment showed that the introduction of carbon fibers leads to an increase in the fracture stresses, the flexural modulus; the maximum increase was observed for the carbon fiber content q = 0.01 pts.wt. (fl = 71.0 MPa, E = 3.8 GPa, W = 7.8 kJ/m2 ). The heat resistance of composite materials at this content of carbon fibers is maximal (T = 337 K), and the coefficient of linear thermal expansion (CLTE) is minimal and decreases in all temperature ranges (compared to the matrix). It was found, that the introduction of cotton fibers at a content q = 0.02 pts.wt. into the composition leads to an increase of the flexural modulus from E = 3.6 GPa (matrix) to E = 3.8 GPa and flexural stresses from fl = 50.4 MPa to fl = 55.2 MPa. The impact strength of such materials decreases from W = 8.3 kJ/m2 to W = 4.9 kJ/m2 . The results of the study of physical and mechanical properties of composite materials with the addition of cotton fibers were confirmed by thermophysical properties. It was found, that the heat resistance of materials increases from T = 335 K to T = 338 K at this content. The developed composite materials filled can be used to protect equipment, which are exposed to high temperatures or dynamic loads at moderate temperatures

Multi-Scale Analysis and Testing of Tensile Behavior in Polymers with Randomly Oriented and Agglomerated Cellulose Nanofibers.

Cellulose nanofiber (CNF) has been accepted as a valid nanofiller that can improve the mechanical properties of composite materials by mechanical and chemical methods. The purpose of this work is to numerically and experimentally evaluate the mechanical behavior of CNF-reinforced polymer composites under tensile loading. Finite element analysis (FEA) was conducted using a model for the representative volume element of CNF/epoxy composites to determine the effective Young’s modulus and the stress state within the composites. The possible random orientation of the CNFs was considered in the finite element model. Tensile tests were also conducted on the CNF/epoxy composites to identify the effect of CNFs on their tensile behavior. The numerical findings were then correlated with the test results. The present randomly oriented CNF/epoxy composite model provides a means for exploring the property interactions across different length scales.