Fiber Reinforced Resin Matrix Composites Research Articles

Equol-based epoxy resin as an ideal substitute for the diglycidyl ether of bisphenol A (DGEBA)

The development of high-performance bio-based epoxies with excellent mechanical properties, heat resistance and flame retardant properties is essential to mitigating the resource and environmental burdens caused by the widespread utilization of petroleum-based epoxies. This work focuses on the synthesis of a bifunctional epoxy resin (EEU) with the rigid tetrahydrobenzopyran ring derived from equol. The structure of the EEU epoxy resin was characterized, and using 4,4′ diamino diphenyl sulfone as the curing agent, the rheological properties, curing behavior and comprehensive properties of cured resin were studied. The results demonstrate that EEU-DDS presents the same curing behavior as DGEBA-DDS. The mechanical properties heat resistance and flame retardant properties of EEU-DDS are superior to DGEBA-DDS. The tensile strength, tensile modulus and glass transition temperature reached to 94.0 MPa, 3.62 GPa and 221 °C, respectively, higher than those of DGEBA-DDS (83.2 MPa, 2.81 GPa and 203 °C). EEU-DDS reached the V-1 rating in UL-94 tests with a high limiting oxygen index (LOI) (28 %), and the peak heat release rate and smoke release rate of 631 kW/m2 and 0.155 m2/s were significantly lower than that of DGEBA-DDS. The flame retardant mechanism was proven to be gas-coacervated phase synergistic flame retardant. In addition, the interlamellar shear strength (ILSS), bending strength, and impact strength of carbon fiber reinforced resin matrix composites prepared by EEU-DDS reached 97.9 MPa, 1281 MPa, and 81.3 kJ/m2, respectively, higher than those of DGEBA-DDS. Therefore, equol-based epoxy resin can serve as an ideal alternative to petroleum-based bisphenol A-type epoxy resin, offering superior comprehensive properties.

Research on Microwave Pyrolysis Recovery and Reuse Performance of Carbon Fiber Composites.

Carbon fiber-reinforced resin matrix composites find extensive applications across various industries. However, their widespread use also generates significant waste, leading to resource depletion and environmental concerns. Studying the production of composite materials using recovered carbon fiber is imperative to mitigate the environmental impact associated with waste from carbon fiber-reinforced resin matrix composites and optimize resource utilization. In this study, carbon fiber was reclaimed using the microwave pyrolysis-oxidation process. The reclaimed carbon fiber underwent a cutting process to produce shorter carbon fibers tailored to specific requirements, which were then used to fabricate composite plates reinforced with epoxy resin. The mechanical characteristics of the composite were analyzed, along with SEM, XPS, infrared, Raman, and contact angle analyses conducted on the recovered carbon fiber. The test findings suggested minimal variation in the surface morphology of the recovered carbon fiber materials. Post-recovery, an increase in the quantity of oxygen-containing functional groups was observed on the carbon fiber surface. Additionally, the contact angle between the carbon fiber surface and the epoxy adhesive decreased. The mechanical properties of the composite produced from the recovered carbon fiber decreased, including the impact strength, tensile strength, and bending strength, with the impact strength dropping by 24.14%, tensile strength by 15.94%, and bending strength by 8.24%, while maintaining overall reusability, thus paving the way for the comprehensive utilization of carbon fiber resources.

Simulation method for filling stage in liquid composite molding based on a two-phase flow volume of fluid model

Liquid composite molding (LCM) is a process for manufacturing fiber-reinforced resin matrix composites. The chemical rheological properties of resin in the filling stage of LCM will produce a non-isothermal flow process that includes multi-field coupling of thermal field, flow field, and chemical field. During the filling stage, the resin is injected into a closed mold pre-laid with a fiber at a certain temperature and pressure to flow continuously and undergo a curing chemical reaction. The viscosity of resin changes constantly under the influence of temperature and the curing reaction, which affects the flow of resin. The simulation of this multi-field coupling filling stage in LCM can provide an effective reference for the design of process parameters. The simulation method of the filling stage in LCM is studied in this paper. The mathematical model of the filling stage is derived based on the air–resin two-phase flow volume of the fluid model. Based on the secondary development of the ANSYS FLUENT software, the mathematical model is solved to realize the simulation. The parameters of an alkali-free glass fiber plain weave fabric are measured and the calculation model of thermosetting resin viscosity is established by designed experiments, which are applied in simulation. The filling stage experiment of LCM is designed to verify the accuracy of simulation results. Meanwhile, by comparing with the traditional simulation method, it is found that the data error obtained by the simulation method in this paper is significantly reduced.

A review of the effect of hydrothermal aging on the mechanical properties of 2D fiber‐reinforced resin matrix composites

Abstract2D fiber reinforced resin matrix composites (2D FRRMC) are widely applied for aerospace, generator blades, and other high‐end equipment manufacturing fields due to their excellent mechanical properties. However, 2D FRRMC will face a variety of complex environments in the service process, and the long‐term complex environment will significantly impact the physical and mechanical properties of 2D FRRMC. It is necessary to understand and analyze the changes of materials during service. A comprehensive review of the research on the effect of hydrothermal aging on the mechanical properties and re‐ drying of 2D FRRMC in recent years was presented in this article, which contains interlaminar shear properties, compression properties, tensile properties, and aging mechanism, etc. Finally, the current challenges and prospects of 2D FRRMC were discussed. These discussions and proposed strategies will enlighten thoughts and offer ways to apply 2D FRRMC in complex environments better, study 2D FRRMC in complex environments, and study the effects of hydrothermal aging on materials in the future.

Geometric phase analysis for characterization of 3D morphology of carbon fiber reinforced composites

In carbon fiber-reinforced resin matrix composites, differences in the mechanical properties of carbon fibers and matrix resins can lead to differences in height, causing step faults at the interphase during grinding and polishing. Accurately and efficiently characterizing the step height at the interphase is crucial for analyzing the mechanical properties and residual stress distribution of the composite materials. In this paper, an orthogonal grating, with a frequency of 10,000 lines/mm, was prepared on the surface of the composite material using the SEM electron beam grating technique. The surface morphology of the T700 carbon fiber-reinforced epoxy resin matrix composite was analyzed using the geometric phase analysis method. The average step height between the fiber and matrix was found to be 128.6 nm. Moreover, the geometric phase analysis method can provide a morphology distribution map within the range of 155 × 100 μm2. This research will provide an effective way to quantitative characterization of three-dimensional surface morphology of composite materials.

Numerical analysis of graphene oxide modified glass fiber/epoxy resin composites

Graphene is extensively used as a functional material due to its superb heat transfer and electrical conductivity properties. In this paper, sample graphene oxide /glass fiber/epoxy resin composites were prepared by ultrasonic decentralization. The heat transfer and stress distribution of the graphene-doped fiber-reinforced resin matrix composites were simulated by mathematical modelling. The reliability of the numerical heat transfer model is illustrated by comparing the measured temperature field distribution of the graphene oxide/glass fiber/epoxy composite samples with the numerical simulation results. It is also shown that graphene particles can facilitate heat transfer and the epoxy resin in the composite expands significantly more than the fibers, so the compressive stress on the fibers at the interface strengthens the bond between resin and fibers. Still, the thermal stress can cause the glass fiber ends to detach from the resin material and affect the material life.

Study on the Stability of a Repair Process for Carbon Fiber Laminates

Carbon fiber-reinforced resin matrix composites are often used in the surface structure of helicopters. In the process of flight, the structure often suffers from different degrees of damage due to the influence of the harsh environment. To explore the superiority of the repair method and obtain a good repair process, the intact and damaged carbon fiber composite laminates were prepared in this paper. The damaged specimens were repaired by single-sided double-layer patch bonding. The allowable value of tensile strength of carbon fiber laminates was tested, and the mechanical properties of carbon fiber composite laminates after repair were studied. Combined with the failure mode of the specimen after failure, the results show that the mechanical properties of the repaired specimen can be restored to about 81.9 % of the non-destructive specimen. The single-sided double-layer patch can effectively improve the mechanical properties of the middle loading area. The repair process has high reliability and good stability, which provides a new method for the repair of the composite laminate structure.

Enhanced mechanical properties of ramie fabric/epoxy composite laminates by silicon polymer

Replacing artificial fibers with natural fibers to fabricate fiber-reinforced resin matrix composites is a research hotspot at present. How to improve the poor compatibility between plant fiber and resin matrix is hot spots in this area. Our work is aim to modify RFF reinforced epoxy resin (RFF/EP) composite laminates with silicon polymer (PSOL) and improve the performance of the composite laminates. The results indicate that the interfacial adhesion between EP and RFF was effectively improved after PSOL modification, which enhance the mechanical properties (including interlaminar shear strength, flexural strength and tensile strength) of the PSOL/RFF/EP composite laminates. And the thermal stability of the modified composite laminates is maintained as the RFF/EP composite laminate. This method further expands the potential application for natural fibers to replace artificial fibers.

Mechanical properties and wear resistance of Cf / epoxy resin composites with in-situ grown SiC nanowires on carbon fibers

ABSTRACT Carbon fiber-reinforced resin matrix composites have been utilized as structural and bearing parts in aerospace because of their high specific strength and modulus. To improve the mechanical properties and wear resistance of carbon fiber-reinforced epoxy resin composites, we propose the in-situ growth of SiC nanowires on the surface of carbon fiber by a Chemical Vapor Deposition method. The effect of the addition of nanowires on the mechanical strength and wear resistance of carbon fiber-reinforced epoxy resin composites was investigated. The results indicated that the tensile strength and bending strength of SiCnws / C f / epoxy resin composites increased by 13.8% and 16.2% on the condition that the concentration of Ni(NO3)2 catalyst was 0.1 mol/L, respectively. The improvement of the mechanical properties could be attributed to the mechanical interlocking affection between carbon fiber and SiC nanowires. In addition, due to SiC nanowires with a three-dimensional network structure on the surface of carbon fiber, the stronger adhesive force between epoxy matrix SiC nanowires protected the resin matrix and carbon fiber from abrasion. The wear rate of SiCnws / C f / epoxy composites was reduced by 98.1%.

Study on wear resistance of local aluminum alloy reinforced by carbon fiber transfer membrane region

In order to study the effect of fiber reinforced resin matrix composites on the friction properties of aluminum alloy, 7075 aluminum alloy, Carbon fiber reinforced plastic (CFRP) and 7075-Al/CFRP hybrid samples were selected for pin-disk friction test. White light interference and scanning electron microscopy were used to analyze the surface morphology of the friction samples. Secondly, the formation process of the transfer membrane was analyzed by Raman test and energy spectrum. Finally, the strength of the transfer film was verified by scratch test. The results showed that the friction coefficients of 7075-W and 7075-T6 aluminum alloy are 0.419 and 0.398, and the wear rates are 0.288% and 0.273%, respectively. For CFRP and 7075-Al/CFRP hybrid samples, the microscopic study of friction interface showed that CFRP and aluminum alloy abrasive particles exchanged elements under the dual action of pressure and shear force, thus forming Transfer Membrane Region (TMR). TMR with strong self-lubrication preferentially supported the friction load during the friction process, thus reducing the friction and wear of aluminum alloy. The friction coefficient and the wear rate of the 7075-Al/CFRP hybrid sample were reduced by 62.5% and 78.2%, respectively in comparison to pure 7075 aluminum alloy sample.

Study on Optimization of Drilling Parameters for Laminated Composite Materials

Fiber-reinforced resin matrix composites have been widely used in aerospace, construction, transportation and other industries due to their excellent mechanical properties and flexible structural design. However, due to the influence of the molding process, the composites are easily delaminated, which greatly reduces the structural stiffness of the components. This is a common problem in the processing of fiber-reinforced composite components. In this paper, through the combination of finite element simulation analysis and experimental research, drilling parameter analysis was carried out for prefabricated laminated composites, and the influence of different processing parameters on the processing axial force was qualitatively compared. The inhibition rule of variable parameter drilling on the damage propagation of initial laminated drilling was explored, which further improves the drilling connection quality of composite panels with laminated materials.

Buckling of helically wound composite cylinders under uniform external pressure

ABSTRACT This study investigated the buckling behaviours of helically wound composite cylinders subjected to uniform external pressure. Three composite cylinders with lengths 180, 280, and 380 mm were manufactured through ±55° winding. Cylinders with a wall thickness of 3.12 mm and inner radius of 103 mm were constructed from carbon fibre reinforced resin matrix composites. Externally hydrostatic tests were conducted to determine the collapse strength and postcollapse modes of the three cylinders. Furthermore, the analytical, linear eigenvalue, and Riks methods were used to study their buckling behaviours. The experimental, analytical, and numerical data agreed well with each other. The Riks method considers Hashin damage initiation and linear damage evolution and can therefore be used to reasonably estimate the postcollapse modes of cylinders.

Application of fibre reinforced resin matrix composites in the reinforcement of high voltage transmission towers

Application of fibre reinforced resin matrix composites in the reinforcement of high voltage transmission towers

Application of fibre reinforced resin matrix composites in the reinforcement of high voltage transmission towers

Application of fibre reinforced resin matrix composites in the reinforcement of high voltage transmission towers

Predicting and Improving Interlaminar Bonding Uniformity during the Robotic Fiber Steering Process.

With their high specific stiffness, corrosion resistance and other characteristics, especially their outstanding performance in product weight loss, fiber-reinforced resin matrix composites are widely used in the aviation, shipbuilding and automotive fields. The difficulties in minimizing defects are an important factor in the high cost of composite material component fabrication. Fiber steering is one of the typical means of producing composite parts with increased strength or stiffness. However, fiber waviness is an important defect induced by fiber steering during the fiber placement process. Meanwhile, the laying speeds of the inner and outer tows along the path width direction are different during the fiber steering process, resulting in different interlaminar bond strengths. Therefore, the fiber waviness and uneven interlaminar bonding strength during fiber steering not only affect the dimensions of a composite product, but also influence the mechanical properties of the part. This study aims to reduce fiber waviness and improve interlaminar bonding uniformity along the path width direction using a multi-piece compaction roller. By analyzing the mechanism of the generation of fiber waviness, the interlaminar bonding strength for each tow during fiber steering is investigated. Through analyzing and optimizing the compaction force, laying temperature and laying velocity during fiber steering experiments, the optimization approach is verified.

Study on the aging properties of 3D woven composites under corrosive conditions

Different aging conditions have an important influence on the performance of carbon fiber composites. In this study, the properties of three-dimensional woven carbon fiber reinforced resin matrix composites were investigated and analyzed in three different aging environments (distilled water immersion, 30% H2SO4 solution immersion, and 10% NaOH solution immersion) at 60°C. Mass change, moisture absorption change, Fourier transform infrared spectra (FTIR), surface morphology before and after aging, glass transition temperature (Tg), compression properties, bending properties, and interlayer shear properties were analyzed. The results showed that the immersion in 10% NaOH solution made the specimens destroyed and the aging process was chemically changed. Distilled water immersion and 30% H2SO4 solution immersion moisture absorption rate to meet the FICK law, the aging process only physical changes. The surface of the composite specimens under the three aging conditions produced different degrees of cracks and different degrees of debonding at the interface between the fibers and the resin matrix. The Tg, flexural properties, interlaminar shear properties, and compressive properties of the aged specimens all showed different degrees of degradation.

Design, preparation, and performance characterization of low temperature environment-resistant composite resin matrix in rocket fuel

Cryogenic technology is a vital part of our society, not only in our lives, but also in the field of cutting-edge technology. The research and application of cryogenic technology is involved in many important projects in many countries and even in the world, such as aviation, aerospace, energy, transportation, and medicine. With its high specific strength and high specific modulus, carbon fiber reinforced resin matrix composite materials have gradually become the key material for aerospace vehicles, with significant advantages in reducing structural weight and improving structural efficiency. However, in the ultra-low temperature environment such as liquid hydrogen and liquid oxygen, the overall structure of carbon fiber reinforced resin matrix composites is severely tested by the environment, and it is extremely important to evaluate the mechanical properties of the composites under ultra-low temperature due to the difference of their material structure and properties from those of traditional materials, and the difference of thermal expansion coefficients between the reinforcing material carbon fiber and the resin matrix in rocket fuel. In this paper, the epoxy resin-based composite system was prepared by modifying TDE-85 epoxy resin with low-viscosity cyanate resin through molecular structure design, which is suitable for ultra-low temperature environment. The surface tension and dynamic contact angle of the modified epoxy resin are better than those of the pure epoxy resin, and it can form a good infiltration with carbon fiber and the interfacial properties of the composite are excellent. Secondly, the modified epoxy resin-based composite unidirectional plate was prepared by wet winding molding process, and the low-temperature mechanical property test specimens were prepared according to the relevant test standards. The mechanical properties were tested at −196℃, −150℃, −90℃ and room temperature 25℃ to obtain the low-temperature mechanical properties of the composite system, which provided the basis for the design of the composite system in the ultra-low temperature environment. Finally, the microstructure of the epoxy matrix composites was characterized by SEM method after the different temperature tests. The material structure, morphology, and composition were characterized by field emission scanning electron microscopy (FESEM, M400 FEI) with energy dispersive X-ray spectroscopy (EDS). In this paper, TDE-85 epoxy resin was modified with low viscosity cyanate resin to produce a modified epoxy resin suitable for ultra-low temperature environment, and the process properties of the epoxy resin were characterized. The surface tension of the modified epoxy resin was 43.405 mN/m, which was significantly lower than that of the pure epoxy resin at room temperature of 48.814 mN/m. Therefore, the modified epoxy resin had better flowability and required less time to wet the fibers during the molding process, resulting in higher molding efficiency.

Characterization of the effects of testing temperature on the interfacial shear strength of fiber/resin single-filament-composite

In the micromechanical test of fiber-reinforced composites, single fiber pull-out test is the most widely used test method. However, for high performance fibers/matrix, different test equipment and sensor accuracy can affect the single fiber pull-out test results very much. In this study, an innovative single fiber pull-out test method is proposed for testing the interfacial shear strength (IFSS) of high performance fibers/resins at different temperatures. Single fiber pull-out test was carried out on PBO fiber/epoxy resin (EP) composites at room temperature and elevated temperature. The IFSS was found to have an inverse relationship with the test temperature. The IFSS value of PBO/EP decreased from 25.25 MPa at room temperature to 6.25 MPa as the temperature approached the glass transition temperature. COMSOL simulations showed that fiber pull-out with angular tilt exhibited better interfacial strength, demonstrating the validity of the method. The results of this paper provide ideas to study the effect of temperature on the mechanics of fiber-reinforced resin matrix composites and expand the way to design stiffer, stronger and more robust composites.

Numerical Investigation on the Design and Optimization of Stacking Pattern for High Flexural Performance Carbon Fiber Reinforced Resin Matrix Composites

Numerical Investigation on the Design and Optimization of Stacking Pattern for High Flexural Performance Carbon Fiber Reinforced Resin Matrix Composites

Mask-Point: Automatic 3D Surface Defects Detection Network for Fiber-Reinforced Resin Matrix Composites.

Surface defects of fiber-reinforced resin matrix composites (FRRMCs) adversely affect their appearance and performance. To accurately and efficiently detect the three-dimensional (3D) surface defects of FRRMCs, a novel lightweight and two-stage semantic segmentation network, i.e., Mask-Point, is proposed. Stage 1 of Mask-Point is the multi-head 3D region proposal extractors (RPEs), generating several 3D regions of interest (ROIs). Stage 2 is the 3D aggregation stage composed of the shared classifier, shared filter, and non-maximum suppression (NMS). The two stages work together to detect the surface defects. To evaluate the performance of Mask-Point, a new 3D surface defects dataset of FRRMCs containing about 120 million points is produced. Training and test experiments show that the accuracy and the mean intersection of union (mIoU) increase as the number of different 3D RPEs increases in Stage 1, but the inference speed becomes slower when the number of different 3D RPEs increases. The best accuracy, mIoU, and inference speed of the Mask-Point model could reach 0.9997, 0.9402, and 320,000 points/s, respectively. Moreover, comparison experiments also show that Mask-Point offers relatively the best segmentation performance compared with several other typical 3D semantic segmentation networks. The mIoU of Mask-Point is about 30% ahead of the sub-optimal 3D semantic segmentation network PointNet. In addition, a distributed surface defects detection system based on Mask-Point is developed. The system is applied to scan real FRRMC products and detect their surface defects, and it achieves the relatively best detection performance in competition with skilled human workers. The above experiments demonstrate that the proposed Mask-Point could accurately and efficiently detect 3D surface defects of FRRMCs, and the Mask-Point also provides a new potential solution for the 3D surface defects detection of other similar materials