• Title/Summary/Keyword: Carbon Fiber Plate

Search Result 211, Processing Time 0.031 seconds

Flexural Behaviors of Reinforced Concrete Beams Strengthened with Fiber-Steel Composite Plates (섬유-강판 복합플레이트로 보강된 RC 보의 휨 거동에 관한 연구)

  • Cho, Baik-Soon;Kim, Seong-Do
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.21 no.5
    • /
    • pp.483-491
    • /
    • 2008
  • The effectiveness of a new fiber-steel composite plate designed specifically to be used for strengthening of reinforced concrete members has been investigated. Twelve reinforced concrete beams were tested. Seven of the beams were strengthened with carbon fiber-steel composite plate(CSP), four of the beams were strengthened with glass fiber-steel composite plate(GSP), and one beam was used as a control specimen. The experimental results showed that new strengthening system controls the premature debonding and provides a more ductile failure mode than other conventional strengthening systems. The observed ductility ratios were $3.01\sim3.81$ and $3.55\sim4.95$ for strengthened beam with CSP and GSP, respectively. The maximum load was increased by 115% and 107% for strengthened beam with CSP and GSP, respectively, comparing with control beam. In addition, experimental and analytical results were well agreed.

Analysis of various composite patches effect on mechanical properties of notched Al-Mg plate

  • Meran, Ahmad P.;Samanci, Ahmet
    • Steel and Composite Structures
    • /
    • v.25 no.6
    • /
    • pp.685-692
    • /
    • 2017
  • In this study, the effect of various adhesively bonded composite patches on mechanical properties of notched Al-Mg alloy plates was analyzed. For this purpose firstly, the un-notched and notched specimens were fabricated from 5086 Al-Mg alloys which have been used in armor-plated military vehicles. The surface notches as a flaw were machined with circular cutting tool to form notch aspect ratio a/c=0.15 and notch-to-thickness ratios a/t=0.5 in the radial direction on the test specimens. Then, various composite patches which reinforced by glass, carbon and Kevlar fibers were bonded adhesively at elliptically surface notches. Finally, experimental measurements conducted by applying tensile static loading. The experimental results showed that repairing with composite patches with order of carbon, glass and Kevlar fibers have remarkable effect on tensile strength of the notched plate. Also the finite element models were developed using Abaqus/Explicit code to predict the tensile strength and elongation of unrepaired notched specimen and specimen repaired by carbon fiber composite patch. The comparison between numerical and experimental results showed good agreement between them and proved the accuracy of numerical modeling.

Multi-stage Compression Molding Technology of Fast Curing CF/Epoxy Prepreg (속경화용 탄소섬유/에폭시 프리프레그의 다단 압축 성형기술)

  • Kwak, Seong-Hun;Mun, Ji-Hun;Hong, Sang-Hwui;Kwon, Soon-Deok;Kim, Byung-Ha;Kim, Tae-Yong
    • Composites Research
    • /
    • v.34 no.5
    • /
    • pp.269-276
    • /
    • 2021
  • PCM (Prepreg Compression Molding) process is a high-speed molding technology that can manufacture high-quality CFRP (Carbon Fiber Reinforced Plastic) parts. Compared to the autoclave process, it generates less waste and can significantly reduce cycle time, so various studies are being conducted in the aerospace and automobile industries. In this study, in order to improve the quality of the PCM process, a molding method was developed to increase the compression pressure of the press step by step according to the curing behavior of the prepreg. It was confirmed that this multi-stage compression molding technology is a good means to produce high-quality CFRP products and shorten cycle times. And, the laminated prepreg at room temperature was immediately put into the mold and preheated and molded at the same time, so that it could be molded without a separate preheating process. In addition, as a result of applying the same process conditions optimized for flat plate molding to three-dimensional shapes, a product similar to a flat plate in appearance could be made without the process of establishing process conditions.

Fracture Behavior of Fiber Reinforced Composites under tensile and Bending Loadings (섬유강화 복합재료의 인장 및 굽힘에 의한 파괴)

  • Nam, Gi-U;Mun, Chang-Gwon
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.30 no.1
    • /
    • pp.45-52
    • /
    • 1994
  • The study was conducted to evaluate reliability of the longitudinal tensile properties of unidirectional carbon fiber reinforced composites. Two kinds of carbon fiber reinforced composites laminates were tested in order to examine the factors of variability and have the information concerning reliability improvement. Temperature dependence of the strength and its variability were investigated by means of testing at two kinds of temperatures. Statistical distributions of the respective mechanical properties were obtained from the tensile tests. As a result, strength of composites was directly proportional to the ultimate strain and was not proportional to the elastic modulus. The fracture behavior in bending of notched plate was studied for a composite material. The uniform bending tests of notched plates have been carried out for a wide range of notch radii. The experiment shows that the nominal stress at failure decreased with decreasing notch radius and it approaches a constant value when the notch radius is less than about 0.3mm. The critical maximum stress is governed by notch root radius alone in the case of a constant thickness of specimen.

  • PDF

A study on the electrical and mechanical properties of PEMFC bipolar plate by thermoplastic composite injection molding process (열가소성 복합소재를 이용하여 사출성형 한 PEMFC용 bipolar plate의 전기전도도 및 기계적 특성 연구)

  • Yoon, Yong-Hun;Kim, Dong-Hak
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.12 no.4
    • /
    • pp.1999-2004
    • /
    • 2011
  • This research aims to develop polymer composites which can be used for PEMFC bipolar plate by injection molding process. Considering the moldability and stiffness, we used LCP(Liquid crystal polymer) as base resin. In order to improve electrical conductivity and mechanical properties, we chose carbon black, and both synthetic graphite and expanded graphite. The composites with different recipe are prepared for injection molding of PEMFC bipolar plate and CAE(Computer Aided Engineering) analysis was performed to predict melt flow and fiber orientation We did successfully fabricate the ASTM specimens by injection molding, and measure the electrical conductivity of the samples by using four point probe device. We measured mechanical properties such as flexural strength, flexural modulus and Izod impact strength. Conclusively, the electrical conductivity increased with increasing additive concentration, but both flexural strength and Izod impact strength decreased due to the brittle nature of carbon-based additives.

Analyze of the interfacial stress in reinforced concrete beams strengthened with externally bonded CFRP plate

  • Hadji, Lazreg;Daouadji, T. Hassaine;Meziane, M. Ait Amar;Bedia, E.A. Adda
    • Steel and Composite Structures
    • /
    • v.20 no.2
    • /
    • pp.413-429
    • /
    • 2016
  • A theoretical method to predict the interfacial stresses in the adhesive layer of reinforced concrete beams strengthened with externally bonded carbon fiber-reinforced polymer (CFRP) plate is presented. The analysis provides efficient calculations for both shear and normal interfacial stresses in reinforced concrete beams strengthened with composite plates, and accounts for various effects of Poisson's ratio and Young's modulus of adhesive. Such interfacial stresses play a fundamental role in the mechanics of plated beams, because they can produce a sudden and premature failure. The analysis is based on equilibrium and deformations compatibility approach developed by Tounsi. In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both the reinforced concrete beam and bonded plate. The paper is concluded with a summary and recommendations for the design of the strengthened beam.

Impact localization method for composite structures subjected to temperature fluctuations

  • Gorgin, Rahim;Wang, Ziping
    • Smart Structures and Systems
    • /
    • v.30 no.4
    • /
    • pp.371-383
    • /
    • 2022
  • A novel impact localization method is presented based on impact induced elastic waves in sensorized composite structure subjected to temperature fluctuations. In real practices, environmental and operational conditions influence the acquired signals and consequently make the feature (particularly Time of Arrival (TOA)) extraction process, complicated and troublesome. To overcome this complication, a robust TOA estimation method is proposed based on the times in which the absolute amplitude of the signal reaches to a specific amplitude value. The presented method requires prior knowledge about the normalized wave velocity in different directions of propagation. To this aim, a finite element model of the plate was built in ABAQUS/CAE. The impact location is then highlighted by calculating an error value at different points of the structure. The efficiency of the developed impact localization technique is experimentally evaluated by dropping steel balls with different energies on a carbon fiber composite plate with different temperatures. It is demonstrated that the developed technique is able to localize impacts with different energies even in the presence of noise and temperature fluctuations.

An Experimental Study on Improved Bearing-Capacity of Reinforced Concrete Beam Using Reinforcement Materials (보강재를 사용한 철근 콘크리트 보의 내력보강에 관한 실험적 연구)

  • 홍상균;박기철;정헌수
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1996.10a
    • /
    • pp.495-500
    • /
    • 1996
  • In this paper, it is the effect of using fiber sheet (Carbon Fiber Sheet & Aramid Fiber Sheet) and Steel Plate for reinforced concrete beam, 25 specimens are tested, 16 specimens for bending capacity and the other are for shear capacity. In the case of bending testing, the kind and quantity of the reinforcement materials, the bondage and the existence of crack were selected as experimental variables. And in the case of shear testing, it is testified the effect of reinforcement with the variables of the method of reinforcement (side type and U type). As a result, using the reinforcement meterials can increase the capacity of bending stress.

  • PDF

A Study on Structural Performance Evaluation of RC Beams Strengthened with CFRP Plate (탄소섬유판으로 보강된 철근콘크리트 보의 보강성능에 관한 연구)

  • Kim Joong-Koo
    • Korean Journal of Construction Engineering and Management
    • /
    • v.5 no.6 s.22
    • /
    • pp.212-217
    • /
    • 2004
  • Carbon fiber reinforced plastic(CFRP) plate Is one of the alterative materials for soengthening of reinforced and prestressed connote members due to excellent strength and light weight In this paper, the behavior of beams strengthened with CFRP plate and CFS(Carbon fiber sheet) is observed and analyzed from the test results. Especially specimens with thick plate is tested when large moment and large shear lone appear in same position. The main failure mode is a peeling-off of the CFRP plate near the loading points due to flexural-shear crack, Because of this failure mode, failure load is not linearly proportional to the thickness of CFRP plates. When beam is wrapped with CFS around oかy loading point it does not influence on the failure loads. Depending on the loading pattern, it is necessary to consider different design criteria for reinforced concrete members with external reinforcement. When line moment and large shear force appear in same location, maximum thickness may limit to 0.6mm and ratio between moment of strengthened beam and moment of unstrengthened beam is proposed 1.5-2.0. In order to use the plate of thicker than 6mm, CFS may be extended to the location which moment of strengthened beam is 1.5 times than moment of unstrengthened beam.

Vibrational characteristics of multi-phase nanocomposite reinforced circular/annular system

  • Zhou, Changlin;Zhao, Yi;Zhang, Ji;Fang, Yuan;Habibi, Mostafa
    • Advances in nano research
    • /
    • v.9 no.4
    • /
    • pp.295-307
    • /
    • 2020
  • The vibrational characteristics of Multi-Phase Nanocomposite (MPC) reinforced annular/circular plate under initially stresses are presented using the state-space formulation based on three-dimensional elasticity theory (3D-elasticity theory) and Differential Quadrature Method (DQM). The MPC reinforced annular/circular plate is under initial lateral stress and composed of multilayers with Carbon Nanotubes (CNTs) uniformly dispersed in each layer, but its properties change layer-by-layer along the thickness direction. The State-Space based Differential Quadrature Method (SS-DQM) is presented to examine the frequency behavior of the current structure. Halpin-Tsai equations and fiber micromechanics are used in the hierarchy to predict the bulk material properties of the multi-scale composite. A singular point is investigated for modeling the circular plate. The CNTs are supposed to be randomly oriented and uniformly distributed through the matrix of epoxy resin. Afterward, a parametric study is done to present the effects of various types of sandwich circular/annular plates on frequency characteristics of the MPC reinforced annular/circular plate using 3D-elasticity theory.