Behavior Of Composite Materials Research Articles

Experimental characterization of unidirectional carbon – Carbon composite laminate

Advanced polymeric Composites have wide applications in various industrial sectors of Missile System, Automobile, and Space Structures have been sound prominent and endlessly receiving the wide awareness for many industries. The structural engineer desires to be eminent with the belongings of the composite material structures. The performance of fiber reinforced polymeric composite material beneath dynamic load plays a crucial task in designing such structures. In the recent work, an attempt is made to determine optimum fiber angle and the behavior of the advanced polymeric composite material, i.e., Carbon – Carbon Composites under Tensile and Compressive loads. Mechanical properties, viz., Compressive and Tensile strength are determined by using experimentation method. Hand layup technique is used for fabricating the laminates. FE Analysis (Ansys) is carried out on various fiber angles likely be [0°-90°], [30°], [45°], [60°] to validate the results which is obtained from experimentation.

Effects of an enhanced fibre–matrix adhesion on the fatigue behaviour of composite materials under very high cycle fatigue

The fatigue behaviour of two glass fibre-reinforced epoxy composite materials with a cross-ply layup is investigated in the very high cycle fatigue (VHCF) regime with up to 10^8 load cycles. In addition to the influence on the fatigue lifetime, different materials can also cause a different damage phenomenology. One reference fibre (OC111A) and one fibre with increased fibre–matrix adhesion (SE2020) are tested. The experimental and numerical investigations show that the damage threshold is shifted to higher loads with increased fibre–matrix adhesion, but the damage mode of delaminations becomes more important.

Study on the formation mechanism and mechanical properties of composite foam slurry material for mine plugging

The development of tough, energy and shock absorbing materials is the key to solving the problem of long-term plugging the air leakage to prevent and control coal spontaneous combustion. To study the mechanical behavior and energy absorption characteristics of composite foam slurry material (CFSM) for mine plugging, the effect of activator on the properties of CFSM was investigated, and the whole process of CFSM under uniaxial compression were analyzed systematically. The results indicated that activator could improve the compressive strength of CFSM by dissolving the vitreous structure of slag and generating more hydration products, further improving the structural compactness. Moreover, CFSM exhibited the unique deformation damage patterns and energy absorption effects during stress loading. Based on thecompressive stress-strain curve, the damage failure pattern of CFSM was mainly caused by shear stress and exhibited three main characteristic stages, including elastic-plastic stage, plateau stage and crush compact stage. The material showed elastic deformation of the bubble pores and local micro cracks in the elastic-plastic stage. The platform stage was characterized by the development of fissures until complete penetration. The bubble pores of the material were gradually compacted and became dense in the compacting stage, and ultimately retained a certain compressive strength. Unlike the direct splitting damage of traditional grouting materials, CFSM showed obvious energy and shock absorption effect in the process of compression. Part of the energy was transformed into the elastic energy of the bubble pore for releasing when disturbed by external impact, resulting in deformation of the bubble pore. The other part of the pressure was transformed into plastic fracture energy, causing cracks in the bubble hole or collapse. The findings of this study could help for better understanding of the mechanism of long-lasting prevention coal spontaneous combustion by foamed gelling plugging materials, and eventually provide more ideas for the development of green and safe mine plugging materials.

Ballistic performance of optimised light weight composite armour

This research paper presents a comprehensive investigation into the response of a 3D finite element model when subjected to 7.62 AP projectiles. The study utilises Hetherington's armour composite equation and incorporates the Johnson-Holmquist material model to analyse the strength and failure criteria of the ceramic and Kevlar/epoxy components, respectively. The results highlight the remarkable resilience of the composite armour, demonstrating its ability to withstand projectile velocities up to 1500 m/s. However, as the ballistic velocity limit increases, the armour experiences significant damage, including projectile erosion and panel delamination. Through numerical simulations and advanced modelling techniques, the paper thoroughly explores the failure modes and energy absorption characteristics of composite armour systems under projectile impact. It investigates key parameters such as velocity, acceleration, kinetic energy, internal energy, pressure distribution, displacement, and damage progression. The analysis reveals a progressive decrease in kinetic energy as the projectile interacts with the armour, underscoring the crucial role of energy absorption in preventing projectile penetration. Moreover, the impact velocity influences the distribution of internal energy within the composite armour, with higher velocities leading to greater energy absorption up to a threshold limit. The study also determines the ballistic limit velocity (V50) using the velocity history approach and validates the findings with existing literature. Overall, the research provides valuable insights into the limitations of composite armour and offers important recommendations for designing and improving materials to achieve superior ballistic protection. It emphasises the significance of reaching the maximum ballistic limit while maintaining a lightweight armour structure by optimising the total armour thickness. This study contributes to the advancement of armour technology and enhances our understanding of the behaviour of composite materials under high-velocity impacts. It offers valuable guidance for the development of more robust armour systems suitable for various defence and protection applications.

A numerical framework for modelling tire mechanics accounting for composite materials, large strains and frictional contact

We present a general framework for the analysis and modelling of frictional contact involving composite materials. The study has focused on composite materials formed by a matrix of rubber and synthetic or metallic fibres, which is the case of standard tires. We detail the numerical treatment of incompressibility at large deformations that rubber can experience, as well as the stiffening effect that properly oriented fibres will induce within the rubber. To solve the frictional contact between solids, a Dual Augmented Lagrangian Multiplier Method is used together with the Mortar method. This ensures a variationally consistent estimation of the contact forces. A modified Serial-Parallel Rule of Mixtures is employed to model the behaviour of composite materials. This is a simple and novel methodology that allows the blending of constitutive behaviours as diverse as rubber (very low stiffness and incompressible behaviour) and steel (high stiffness and compressible behaviour) taking into account the orientation of the fibres within the material. The locking due to the incompressibility constraint in the rubber material has been overcome by using Total Lagrangian mixed displacement-pressure elements. A collection of numerical examples is provided to show the accuracy and consistency of the methodology presented when solving frictional contact, incompressibility and composite materials under finite strains.

Heat treatment behavior of Cr in the form of collagen powder and Al2O3 reinforced aluminum-based composite material

In the present study, collagen powder in the form of Cr has been extracted from chrome-containing leather waste. Extracted collagen powder along with alumina has been used as reinforcement with AA6061 matrix material. The composite material was fabricated by the stir casting technique. Comparative behavior of composite material with and without heat treatment was observed. The microstructure image of the Al/5% Al2O3/5% collagen composite has shown the uniform distribution of reinforcement particles. Proper wettability between the collagen powder, alumina, and matrix material was observed after the solidification for Al/5% Al2O3/5% collagen composite material. Tensile strength, hardness, ductility, and impact strength of composite material were significantly improved after the heat treatment process. However, results showed that ball-milled reinforced composite has a higher Young's modulus as compared to heat-treated composite. The percent porosity of aluminum alloy was found to be 0.18%. However, the porosity of Al/5% Al2O3/5% collagen powder ball milled composite material was found to be 1%. The XRD of the heat-treated Al/5% Al2O3/5% collagen powder composite showed the presence of Al, Al2O3, Cr, and Cr2O3 phases. Thermal expansion and corrosion behavior of the composite were also observed to identify the heat treatment effect on Al/Al2O3/collagen powder composite material.

Multiscale study of the process deformation for SiC/SiC composite materials in PIP process

In this paper, the process deformation of 2D SiC/SiC composite materials in the pyrolysis stage of precusor infiltration and pyrolysis process (PIP) is investigated experimentally and computationally through a multiscale study. The pyrolysis process of PCS was described by a kinetic model. The intrinsic properties and behaviors of pyrolysed PCS were characterized experimentally. The macroscopic properties and behaviors of 2D-SiC/SiC composite materials were obtained through the homogenization method. The proposed methodology can successfully predict the process deformation of an L-shaped 2D SiC/SiC composite structure in cyclic PIP process. It is revealed that the pyrolysis of precusor can generate significant chemical shrinkage and stiffness variation, leading to the process deformation of the entire composite structure. Unlike the precusor, the variation of properties and behaviors of composite materials are anisotropic. Furthermore, the cyclic process and the evolution of matrix composition complicate the process deformation. The behavior of composite material is dominated by pyrolysing PCS at first several cycles whereas by pyrolysed SiC at last several cycles. The fundamental understating on process deformation in this paper may benefit the design and the manufacture of SiC/SiC composite materials.

The influence of particle population geometry and slenderness on the mechanical behaviour of a metal-matrix composite material

The influence of particle population geometry and slenderness on the mechanical behaviour of a metal-matrix composite material

Crack nucleation and growth induced by thermal phase transition for polymer bonded energetic composite materials

Understanding thermophysical and thermomechanical damage behaviors of polymer-bonded energetic composite materials (PBECMs) is fundamental to the design of advanced safe munition structures. Herein, the effects of thermal expansion and phase transition in energetic crystal, thermal softening of binders, binder-crystal interface debonding, and heating rate on cracking damage in PBECMs are quantitated from the viewpoint of mechanics. An original thermomechanical crystal model integrating with anisotropic thermoelasticity, thermal expansion and phase transition is developed for energetic crystal. Damage and debonding at the interface and intracrystalline fracture are modelled by a bilinear traction-separation cohesive law. The results show that the occurrence of phase transition induces a prominent increase of volume deformation and contributes to mutual compression between crystals and mismatch shear deformation at the interface, thereby multiplying crack density. Inhomogeneous thermal stress field and crack distributions are related to anisotropic thermal expansion and phase transition behaviors of crystals. The predicted thermally cracking behaviors in PBECMs, including critical temperature to crack formation, crack nucleation position and growth mode, are consistent with experimental results.

Experimental Study and Numerical Modelling on Flexural and Shear Strengthening of RC Beam with Prestressed FRP Bars

Abstract: The most prevalent and widely used building material in the world is reinforced concrete. The primary building material for the majority of constructions, including buildings, bridges, etc., is reinforced concrete. Because of various factors, some of these buildings or portions of them are failing to perform as designed. The best solution to increase the load carrying capacity and extend the useful life of these inadequate structures is to strengthen them because replacing them would need significant investments and not be an appealing alternative. Even though the effectiveness of other techniques is widely accepted,a new effective and promising technique of strengthening civil engineering structures externally is gaining popularity, where fibre-reinforced polymer (FRP) is used. One of the most popular strengthening methods recently is the use of carbon fibre reinforced polymer (CFRP) to strengthen reinforced concrete beams. It provides a desirable way to improve the shear and flexural strengths of RC beams. The manner in which these composites are bonded to the beam has a significant impact on the behaviour of reinforced concrete beams in shear and flexure. The purpose of this study was to present a three-dimensional nonlinear finite element analysis (FEA) of a reinforced concrete beam (RC beam) reinforced by prestressed carbon fibre plate (CFRP plate). While there are many commercial programmes available for three-dimensional nonlinear FEA, each one has a unique ability to represent complex behaviour of composite materials, such as RC beams strengthened with prestressed CFRP plate and the contact interaction. Because of its reputation for accuracy in simulating the behaviour of a range of materials, including concrete, and its potent contact algorithms, the ABAQUS finite element programme was chosen for this work. Steel reinforcements were modelled as elastic- perfectly plastic materials, while concrete was studied using the concrete damage plasticity (CDP) constitutive model. The CFRP plate was modelled as an entirely elastic substance that breaks under the highest tensile strain. Concrete and steel reinforcement were considered to have a perfect connection, and the behaviour of concrete and CFRP plate was represented using a contact model. The FEA's findings were verified against experiment findings that were published in the literature. In terms of load-deflection behaviour, crack patterns, and mode of failure, the results were compared. The proposed FEA model was able to accurately simulate the behaviour of RC beams strengthened with prestressed CFRP plate based on the validation. To find out the impact of the thickness, width, and length of the CFRP plate, as well as the prestressing levels and steel grades, a parametric research was done. In particular, the strength of the RC beam for the ultimate load was shown to be increased by increasing prestressing of the CFRP plate. However, as prestressing increased, the fracture of the CFRP plate altered the mechanism of failure, preventing the ultimate load from increasing further. The use of higher grade steel improved the ability to support additional weight. Although the general load carrying capability of the CFRP plate was increased by lengthening the plate, it was discovered that strengthening RC beams by 25% of their shear span was sufficient and cost- effective. The load-deflection curve, failure modes, and crack patterns from the experiments are fairly reflected in the FE model.

Exploring the Thermophysical Properties of the Thermal Conductivity of Pigmented Polymer Matrix Composites with Barium Titanate: A Comparative Numerical and Experimental Study

This research paper focuses on investigating the thermal conductivity behavior of polymer matrix composite materials, specifically those composed of PSU and BaTiO3, both experimentally and numerically. The thermal conductivity of composites has been studied using a variety of theoretical and semi-empirical methods. However, in cases where the filler concentration is minimal, these models provide a superior estimate. To numerically resolve the thermal heat transfer for an elementary cell, the finite element method is employed in this study. The impact of contact resistance, barium titanate percentage, and quenching temperature on the composite’s effective thermal conductivity and dynamic behavior is given consideration. The results demonstrate that the suggested numerical model is in good agreement with experimental measurements as well as Hatta–Taya and Hashin–Shtrikman’s analytical models. The results provide significant insight into the thermal conductivity behavior of composites, which can inform the development of more effective thermal management solutions for composite materials. Effective thermal management is critical for the successful application of polymer matrix composite materials in various engineering applications. Thermal conductivity is a key factor in thermal management and is influenced by factors such as the concentration of filler particles, their shape, size, and distribution, and the matrix material’s properties.

Multiphase and mesoscale analysis of the mechanical behavior of fiber reinforced concrete

In recent years several laboratory tests have been employed to characterize the nonlinear behavior of composite materials, such as fiber-reinforced concrete (FRC). However, important stress-bridging mechanisms of the FRC structural elements are still under investigation. The acquired knowledge in the laboratory has supported the improvement of the numerical models for predicting mechanisms at the material scale and the load-displacement behavior of the composite. Therefore, the numerical models can be used to develop new advanced composite materials by predicting structural performance under different working conditions. This work proposes a mesoscale-multiphase approach to model FRC materials. The model considers four phases of the FRC material: coarse aggregates, mortar, interfacial transition zone (ITZ), and fibers. Mortar and aggregates are modeled using continuum elements with linear elastic behavior. Truss elements with an elastoplastic material model modeled randomly positioned fibers. Zero-thickness interface elements with a cohesive damage law are introduced at the interface between mortar elements and aggregates to represent the interfacial transition zone. The proposed model was validated by simulating direct tensile and three-point bending experiments. The numerical results of the load-CMOD curves are compared with an excellent agreement to experimental and numerical results reported in the literature. It also captures local cracking effects. Changes in fracture patterns were obtained when explicit fibers were introduced into the numerical model. Finally, this work provides a new methodology to investigate the fracture behavior of FRC structural elements considering an efficient strategy for explicitly modeling the fiber bridging effect by coupling fiber and cohesive finite elements. Comparisons between numerical models and experiments on FRC structural elements illustrate the proposed approach's efficacy.

Degradation of fiber/matrix interface under various environmental and loading conditions: Insights from molecular simulations

Fiber-reinforced polymer composites have been increasingly applied as reinforcing and load-bearing components in building constructions and civil infrastructures. Long-term exposure to changing environmental and loading conditions leads to composite degradation, which is highly related to degraded structure and properties of fiber/matrix interface and consequent interfacial debonding between fiber and matrix at nanoscale. By simulating interfacial structure and interactions with atomistic precision, molecular simulation allows for a high fidelity to interfacial variations as affected by environmental and loading conditions. In this paper, molecular investigations of interfacial degradation between fiber and matrix under various environmental and loading conditions are reviewed. Model construction of interfaces formed by different fibers and matrixes and simulation of various environmental and loading conditions are firstly introduced. Afterwards, mechanical and adhesion properties of molecular interfaces obtained from deformation simulations are presented. Meanwhile, interfacial degradations under various environmental and loading conditions are discussed and underlying mechanisms are revealed. Further discussions on modeling and simulation of molecular interface are proposed for future investigations. Overall, this work reviews previous molecular investigations of interfacial degradation of composites under different environmental and loading conditions, which contributes to evaluation of interfacial behaviors of composite materials during long-term service life.

A nonlocal method to compute effective properties of viscoelastic composite materials based on peridynamic computational homogenization theory

This article presents a computational homogenization framework for viscoelastic composites within the framework of non-ordinary state-based peridynamic theory. The motivation to develop this framework stems from the desire to develop a homogenization scheme that can model processes and phenomena that are driven by nonlocal behaviour such as size effect and fracture for which frameworks based on the classical continuum theory lack the capability of modelling. The proposed framework was used to calculate the effective properties in both time and frequency domains of two viscoelastic matrix-inclusion composite systems, one with an elastic inclusion and viscoelastic matrix, and the other with viscoelastic inclusion and matrix. The results of calculations were found to compare well with results from the literature. A parametric study was also conducted to investigate the influence of nonlocal interaction on the effective properties by varying the horizon size. Results showed that increasing the degree of nonlocality reduces the stiffness of the composite system as well as increase its rate of creep. The capability to account for nonlocal interaction highlights the potential of this proposed scheme to provide a more comprehensive understanding of the behaviour of viscoelastic composite materials over a wide range of material behaviour.

A probabilistic constant amplitude life diagram modeling method for composite materials considering spatial mapping relation

AbstractConventional constant amplitude life diagrams (CLDs) model cannot reasonably describe mean stress effect and stochastic uncertainty present in the fatigue failure process of composite materials. To address this problem, taking the spatial mapping relationship between probabilistic S‐N curves and probabilistic CLD model as an entry point, a probabilistic CLD modeling method is proposed under the assumption of linear equations and the assumption of equiprobable quantile point between static strength distributions and fatigue life distributions. The p‐S‐N curve is established using fatigue test data from different load zones divided by different stress ratios.Subsequently, the p‐CLD model is derived through the spatial mapping relationship of the p‐S‐N curve. The method is validated by fatigue test data of glass fiber/polyester resin composites. The results indicate that the proposed method can offer an accurate description of the probabilistic behavior of composite materials.

A new damage-based failure criterion for nonlinear behavior of fibrous composite materials

In the present paper, a novel combined damage-based failure criterion is being proposed for predicting failure stresses in unidirectional fibrous composite laminas or laminates having a nonlinear material behavior. The present model incorporates the effect of a quantitative damage factor on the final stresses at failure. This is achieved through a new term called the quantitative directional damage-index (QDD-I) which assesses the contribution and effectiveness of damage in each principal material direction on the present failure criterion. From the QDD-I, it is proved that the principal material-direction with a linear or nonlinear stress-strain behavior showed a quantitative damage response on the proposed failure criterion. In a composite lamina, the contribution of fiber-damage and matrix transverse-damage are proved to have minor effects on the failure criterion, while in-plane shear-damage has the major effect. In order to verify the suitability and applicability of the criterion, results are tested using various theoretical and experimental data available from the literature. Furthermore, the model is compared with other failure criteria under both uniaxial and biaxial loading cases from a worldwide comparison, which showed reasonable accuracy and good agreement. Three types of fibrous composite materials are used; Graphite/Epoxy 4617/Modmore-II, Carbon/Epoxy AS4/3501-6, and Boron/Epoxy Narmco 5505.

Effect of Alternating Hybridisation of Fibres on the Physico - Mechanical Behaviour of Composite Materials

Abstract The performance/weight ratio of fiber reinforced polymer matrix composites makes them the material of choice for structural applications in many fields such as aerospace, aeronautics, automotive and civil engineering...etc. In polymer matrix composites, the fibers used as reinforcement are mainly synthetic fibers such as carbon and/or glass fibers. To ensure the low cost of using fiber-reinforced materials in motor vehicles, it is proposed to selectively incorporate carbon fibers to enhance glass fiber composites along the roadway, and to enhance glass fiber composites along the main load path. For this purpose, we conducted a behavioral study of hybrid epoxy thermoset polymer matrix laminates to highlight the influence of alternate hybridization of glass and carbon fibers on the physical-mechanical behavior of the materials.The results obtained show that the alternated hybridation of the fibers has a significant influence on the tensile properties; and it affected the density, hardness and flexural properties significantly.

Comprehensive computational investigations on various aerospace materials under complicated loading conditions through conventional and advanced analyses: a verified examination

Most failures develop as a result of a lack of resistivity information at the internal structure level during typical loading situations such as shock load and impact load. Impact loads have a significant impact on a component’s structural performance. A careful, organized examination of impact load settings and their side effects can reveal how well something can withstand peak loads. First, this study investigated the impact analyses on nine varied lightweight composite materials through a conventional experimental setup and computational tools. So, the best three lightweight materials are shortlisted for further investigation under complicated explicit analysis. Second, the study investigated the behavior of composite materials subjected to rapid loading circumstances in several real-time applications. The applications chosen include bullet crash analysis, unmanned aerial vehicle (UAV) propellers, and car bumpers. The three different principal composites, carbon fiber-reinforced polymer (CFRP), glass fiber-reinforced polymer (GFRP), and Kevlar fiber-reinforced polymer (KFRP), are selected and applied in crash analysis using ANSYS Workbench’s explicit technique-based finite element analysis (FEA). The comparison assessments are conducted using stumpy structural characteristics such as impact stress and equivalent strain. Two distinct grid convergence tests were performed to check whether the computational processes and discretization were correct. The standard methodologies were used on all three selected real-time applications, resulting in error percentages that were within acceptable bounds, ensuring the generation of dependable structural outputs. The ideal composite material is a Kevlar fiber-based composite with minimal defect affectability for all types of crash applications. Furthermore, multidisciplinary optimizations are performed, and the KFRP is verified to give good crash load resistance with reduced dense contribution.

Study to analyze the mechanical strength of composite glass fiber laminated with resin epoxy, resin polyester, and PVC foam under tensile loading conditions by numerically using finite element analysis via Ansys

With the development of material sciences, different kinds of materials are being developed and studied continuously. In order to significantly reduce weight and reduce emissions, composite materials are employed in aerospace, automobile, mechanical, and wind industries all over the world. Advanced polymer composites, which generally consist of continuous fibers inside a polymer matrix, give greater material qualities than metals and provide for the achievement of lightweight structural designs. Additionally, it is expensive and time-consuming to prepare samples and carry out studies with these materials. Therefore, finite element analysis and simulation have been chosen as the method for failure analysis in order to understand the complicated failure behavior of polymer matrix composite material. The primary goal of this study is to investigate the mechanical strength of glass fiber/resin epoxy, glass fiber/resin polyester, and glass fiber/PVC foam at the laminate level and lamina level under tensile loading conditions in Ansys and Ansys ACP. After analysis, this study has revealed that glass fiber laminated with resin epoxy composite has a higher life cycle and high stress-bearing capacity compared to glass fiber/resin polyester, and glass fiber/PVC foam.

Bir üretim kusuru: fiber distorsiyonu ve polimer kompozitlerin termomekanik özellikleri üzerindeki etkisi

The aim of this study is to investigate the effect of a production imperfection, fiber distortions, on the resulting thermoelastic behaviour of composite materials in hexagonally packed Representative Volume Elements (RVEs) with finite elements micromechanical modelling. Instantaneous thermochemical and thermoelastic behavior of resin throughout the cure cycle is implemented into the model. This enables to calculate the resulting thermomechanical properties of composites, having fiber distortions from 0 to 18%, at the end of the cure cycle. It is found that the fiber distortion has great effect on the process induced residual stresses and Coefficients of Thermal Expansion (CTE) values. Equations expressing the variation of residual stresses and CTEs with fiber distortion are obtained. This study proves the importance of consideration of fiber distortions, a manufacturing defect, in finite element modeling of composite materials.