Study on Properties Influence of Carbon Fiber-reinforced Polyimide Composites using Melamine as a Crosslinking Agent

Synthesis of bio-based tetrafunctional benzoxazines derived from furfurylamine: Excellent heat resistance and flame retardant properties

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

A non-corrosion, high strength, light weight material – carbon fiber reinforced polymer (CFRP) is introduced to replace steel as cable system in long-span suspension bridge for improving loading efficiency, reducing maintenance cost, enlarging the span of suspension bridge. The natural vibration characteristics of such new suspension bridge with CFRP cables are investigated by means of finite element in this paper. Two 2000m-span suspension bridges with steel cables and CFRP cables respectively are designed, analyzed, verified and compared. The analysis results provide a picture of the changes in natural vibration characteristics and the wind stability and earthquake-resistant behavior are briefly discussed if CFRP cables were applied.

A facile method to prepare high-performance thermal insulation and flame retardant materials from amine-linked porous organic polymers

A non-corrosion, high strength, light weight material – carbon fiber reinforced polymer (CFRP) is introduced to replace steel as cable system in long-span suspension bridge for improving loading efficiency, reducing maintenance cost, enlarging the span of suspension bridge. Because of the transverse weakness of CFRP, traditional cable saddle is not suitable. The contact forces between main cable and cable saddle slot under final state are investigated with a simplified analytical method. According to the mechanical characteristics of CFRP and the formulas deduced, the design suggestion of cable saddle for CFRP main cable of long-span suspension bridge are proposed.

Strengthening of scaled steel–concrete composite girders and steel monopole towers with CFRP

Hydraulic cylinder is the component with the largest proportion of the weight moving with the host equipment in the hydraulic system. Its lightweight design can help reduce the equipment’s weight and improve the load, endurance and maneuvering performance, which has become the design development direction of hydraulic cylinder at present. Carbon Fiber Reinforced Polymer (CFRP), as a new lightweight material, has the advantages of higher specific stiffness/strength, lower thermal expansion coefficient, better corrosion resistance and fatigue resistance compared with aluminum alloy and high-strength steel materials. The composite manufacturing of hydraulic cylinder with CFRP and metal lining is the main technical means for the lightweight design of hydraulic cylinder at present. However, CFRP has the properties of material anisotropy on the macro level. How to make full use of this characteristic of CFRP and reasonably design the number and direction of fiber layering is the key problem to be solved in lightweight designing of the hydraulic cylinder. In this paper, a hydraulic cylinder served in an aviation actuator is lightweight designed by using the method of combining CFRP and aluminum alloy lining. According to the technology of finite element method, the effect of fiber layup sequence, direction, quantity and metal lining thickness on the performance of composite hydraulic cylinder is studied. The structure design method of the metal lining and the CFRP in the composite hydraulic cylinder are developed, and the effect of 55% weight reduction of the hydraulic cylinder is realized.

Flexural reinforcement on wood beams is intended to increase the maximum load capacity that can be supported by wood beams until they are collapse. One of the most widely used resilient reinforcements currently used is reinforcement using Carbon Fiber Reinforced Polymer (CFRP) which is a combination of high strength with light weight material. This reinforcement is intended for historical buildings that need more load capacity that can be supported due to changes in building function, or the increase of the load on the building. The purpose of this research is to know the effect of reinforcement of wood beams with CFRP and variation of length of reinforcement to flexible strength of wood beams, and beam behavior reinforced with CFRP due to loading. Structural beam testing using mahogany logs with cross sectional size 75x100mm2 along 2 m consisting of 4 types of samples with each type consists of 2 pieces of sample. The first sample was a wood beams without reinforcement, the second sample was a wood beams with a reinforcing length of ¼ spans in the middle, a third sample was a wood beams with a reinforcing length ¾ spans in the middle, and a fourth sample was a wood beams with retrofitting along the length of the span. From the test it is found that the maximum load increase that can be supported by the sample with the length of reinforcement ¼ span, ¾ span, and along the span has increased the maximum load respectively that is 4.393%, 37.340%, and 48.323% compared to wood beams without reinforcement. The average damage occurring in samples with CFRP is debonding failure.

Flexural strength of steel I-beams reinforced with CFRP sheets at tension flange

This article presents an interdisciplinary study that combines historical analysis and experimental research to explore the vulnerability of military drones made from carbon fiber-reinforced polymer to destruction by laser radiation. The work is structured around two interconnected areas: the historical evolution of carbon fiber-reinforced polymer use in military drone construction and the parallel development of high-energy laser systems as precision countermeasures. The historical section traces the trajectory of carbon fiber composites from their initial applications in aerospace and defense industries during the late 20th century to their widespread adoption in military unmanned aerial vehicles, driven by the need for lightweight, durable, and radar-evading materials. Special attention is given to geopolitical, technological, and strategic factors that influenced the increasing reliance on carbon fiber-reinforced polymer for enhancing drone performance in terms of range, payload, and survivability. In parallel, the article examines the emergence of directed energy weapons, focusing on laser systems, as a response to the limitations of conventional kinetic countermeasures in neutralizing fast, small, and low-observable drones. The study outlines how the military’s growing concern with swarm attacks and stealth unmanned aerial vehicles has accelerated investments in laser-based air defense systems capable of engaging airborne targets with high accuracy and low operational cost. The experimental component investigates the mechanisms of laser-induced damage in carbon fiber-reinforced polymer materials through controlled laboratory tests, during which samples are exposed to varying intensities and durations of laser radiation. The results are analyzed to determine the energy thresholds and exposure conditions that lead to effective material destruction. By synthesizing historical and experimental data, the article provides a comprehensive understanding of how past material choices have shaped current vulnerabilities in drone technology and how modern laser systems are specifically adapted to exploit those weaknesses. This integrated approach not only bridges the gap between history and applied science but also contributes to the development of more effective and informed counter-drone strategies in contemporary and future military operations.

Carbon Fiber Reinforced Polymer (CFRP) is a light-weight material with high strength and highly corrosion resistance, and hence is widely applied in aerospace industries. However, milling of CFRP usually generates machining defects (for instance, delamination and pull-out fibres), making processed surface unqualified to meet the requirement of aerospace application. Therefore, prediction for machining quality should be conducted before milling processing to avoid potential loss in massive production. Fracture behaviours of micro-scale fibres and matrix have a significant influence on the final machined surface, and such material removal mechanism can be mainly determined by micro-scale geometrical relationships between carbon fibers and milling teeth. In this paper, a micro-scale geometrical calculation software for CFRP milling is provided based on Dexel model. The software can generate geometrical parameters, for example, cutting angle, cutting length and engagement angle, for the whole milling process. Milling defects and milling forces can be conducted based on those micro-scale geometrical parameters.

Using lightweight materials in aircraft structures, especially carbon fiber reinforced polymer (CFRP), can be an option for achieving aviation's ambitious emission reduction goals. However, using CFRP can be associated with adverse environmental and economic impacts, which can relativize its potential benefits. Nevertheless, the extent of the potential advantages and disadvantages of the increased use of CFRP in the entire airframe is still uncertain, as existing studies relate to specific airframe components or estimated weight savings. This article aims to close this gap by developing detailed life cycle inventories (LCIs) for aircraft with CFRP structures and analyzing the environmental and economic impacts during aircraft production and use. Furthermore, potential reinforcement effects from using sustainable aviation fuels (SAFs) in such aircraft are investigated to determine the overall environmental and economic impacts. For this purpose, three aircraft configurations with different CFRP content are modeled using the aircraft design program “Preliminary Aircraft Design and Optimization”. Afterward, detailed LCIs are developed, and life cycle assessment and environmental life cycle costing are applied. Subsequently, an analysis is conducted where SAFs replace fossil kerosene to investigate the potential for further reductions of environmental and economic impacts. The results of the analysis indicate that increasing the CFRP content in the airframe reduces environmental impacts during production and use. Despite higher production costs, more cost‐effective flight operations are possible. Additionally, there is a reinforcement effect through using SAFs in aircraft with increased CFRP content, which can further reduce climate‐damaging emissions by several magnitudes more compared to lightweight materials alone.

Effect of Tool Geometry and LCO2 Cooling on Cutting Forces and Delamination when Drilling CFRP Composites Using PCD Tools

In the present work, first an attempt has been made to prepare carbon, glass and carbon-glass fibre-reinforced polymer composites, and later, machining of these composites is done on abrasive water jet machine (AWJM) to compare and optimize the machining parameters. Actually, the carbon fibre-reinforced polymer (CFRP) composites, glass fibre-reinforced polymer (GFRP) composites and carbon-glass fibre-reinforced polymer (CGFRP) composites are prepared through vacuum bagging process by using epoxy resin as the polymer matrix. The machining experiments are conducted to analyse the effects of the predominant machining parameters, i.e. cutting speed rate, feed rate and stand-off distance on the required machining characteristics, i.e. surface roughness (Ra), kerf top width (kw) and material removal rate (MRR). The range of values of each parameter is set at three different levels, and Taguchi’s L9 orthogonal array is used to design factors so that all the interactions between the response variables and machining variables can be investigated. Based on the experimental values, second-order regression equations are fitted between each of the response parameters and the machining parameters using Minitab 18 software. The equations are then optimized by defining the three equations of Ra, kw and MRR as the three objectives of a multi-objective optimization problem (MOOP) using a multi-objective optimization algorithm called Elitist Non-dominated Sorting Genetic Algorithm (NSGA-II). Single best compromise solutions with respect to the MOOPs of GFRP, CFRP and CGFRP composites are also determined from the Pareto optimal solutions obtained by NSGA-II. Finally, confirmation tests are conducted on specimens of GFRP, CFRP and CGFRP composites machined at their corresponding optimum parameters given by the GA. It is observed that the optimum values of Ra, kw and MRR of all the optimization problems are closer to the corresponding experimental values of confirmation tests.

A P/N/S-containing high-efficiency flame retardant endowing epoxy resin with excellent flame retardance, mechanical properties and heat resistance