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Статті в журналах з теми "Composite reinforced concrete Effect of temperature on Testing"
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Manoj Kumar Rath. "Condition Assessment of a Reinforced Concrete Residential Building using Non-destructive Testing Methods - A Case Study." Electronic Journal of Structural Engineering 21 (November 30, 2021): 18–33. http://dx.doi.org/10.56748/ejse.21288.
Повний текст джерелаАнотація:
The present study deals with both experimental and numerical investigation on buckling effects of laminated composite plates subjected to varying temperature and moisture. A simple laminated plate model is developed for the buckling of composite plates subjected to adverse hygrothermal loading. A computer program based on FEM in MATLAB environment is developed to perform all necessary computations. The woven fiber Glass/Epoxy specimens were hygrothermally conditioned in a humidity cabinet where theconditions were maintained at temperatures of 300K-425K and relative humidity (RH) ranging from 0-1% for moisture concentrations. All the investigations are made with a symmetric cross-ply laminates. The present study deals with both experimental and numerical investigation on buckling behavior of laminated composite plates subjected to varying temperature and moisture concentration. Quantitative results are presented to show the effects of geometry, material and lamination parameters of woven fiber laminate onbuckling of composite plates for different temperature and moisture concentrations with simply supported boundary conditions with different aspect and side-to-thickness ratios. Experimental results show that there is reduction in buckling loads in KN with the increase in temperature and moisture concentration for laminates with clamped-free-clamped-free boundary conditions
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Protchenko, Kostiantyn. "Residual Fire Resistance Testing of Basalt- and Hybrid-FRP Reinforced Concrete Beams." Materials 15, no. 4 (February 17, 2022): 1509. http://dx.doi.org/10.3390/ma15041509.
Повний текст джерелаАнотація:
The fire resistance of fiber-reinforced polymer reinforced concrete (FRP-RC) elements depends on the temperature performance of the original concrete member, the fire scenario, and FRP reinforcement behavior. In this study, fire resistance tests are described, along with the characteristics obtained during and after applying elevated temperatures, simulating the effects of fire. The tested beams were reinforced with basalt (BFRP) bars and with a hybrid composite of carbon fibers and basalt fibers (HFRP) bars. Fire tests were performed on full-scale beams, in which the midsections of the beams were heated from below (tension zone) and from the sides for two hours, after which the beams were cooled and subjected to flexural testing. BFRP-RC beams failed before the heating time was completed; the best failure was associated with a BFRP reinforced beam that failed approximately 108 min after heating. Contrary to the BFRP-RC samples, HFRP-RC beams were capable of resisting exposure to elevated temperatures for two hours, but showed a 70% reduction in strength capacity when compared to non-heated reference beams. According to the author, the higher resistance of HFRP-RC beams was the result of the thermal expansion coefficient of carbon fibers employed in HFRP, which “prestresses” the beams and enables smaller deflections. The preliminary findings of this study can increase the feasibility of using FRP materials for engineering purposes.
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Mukhtar, Faisal M., and Olaniyi Arowojolu. "Recent developments in experimental and computational studies of hygrothermal effects on the bond between FRP and concrete." Journal of Reinforced Plastics and Composites 39, no. 11-12 (March 22, 2020): 422–42. http://dx.doi.org/10.1177/0731684420912332.
Повний текст джерелаАнотація:
The performance of fiber reinforced polymer externally bonded to concrete is greatly influenced by the environmental conditions to which it is exposed during service. Temperature and humidity are the two common environmental factors that alter the bond behavior of externally bonded fiber reinforced polymer. This paper reviews the experimental and computational approaches used to evaluate the hygrothermal effects—that is, the effect of temperature and humidity—on the durability of the fiber reinforced polymer–concrete bond, as well as on the bond’s performance under loading conditions. Some experimental testing conducted in the laboratory and in situ are critically reviewed and presented. Implemented approaches for improving bond performance under hygrothermal conditions and their modeling techniques are also presented. The paper concludes by discussing the review’s salient issues. The ongoing wide application of externally bonded fiber reinforced polymer creates opportunities for new research on improving and predicting the bond strength of fiber reinforced polymer concrete under hygrothermal conditions.
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Ogrodowska, Karolina, Karolina Łuszcz, and Andrzej Garbacz. "The effect of temperature on the mechanical properties of hybrid FRP bars applicable for the reinforcing of concrete structures." MATEC Web of Conferences 322 (2020): 01029. http://dx.doi.org/10.1051/matecconf/202032201029.
Повний текст джерелаАнотація:
One of the most common causes of the deterioration of concrete structures is the corrosion of steel reinforcement. Reinforcement made from fiber reinforced polymers (FRP) is considered to be an attractive substitution for traditional reinforcement. The most popular FRP reinforcing bars are made of glass fibers. Basalt fiber reinforced polymer (BFRP) is a relatively new material for reinforcing bars. The main drawback of BFRP bars is their low modulus of elasticity. A new type of bar made from hybrid fiber reinforced polymer (HFRP) in which a proportion of the basalt fibers are replaced with carbon fibers can be considered as a solution to this issue; such a bar is presented in this work. The HFRP bars might be treated as a relatively simple modification to previously produced BFRP bars. A different technical characteristic of the fibre reinforced polymer makes the designing of structures with FRP reinforcement differ from conventional reinforced concrete design. Therefore, it is necessary to identify the differences and limitations of their use in concrete structures, taking into account their material and geometric features. Despite the predominance of FRP composites in such aspects as corrosion resistance, high tensile strength, and significant weight reductions of structures – it is necessary to consider the behavior of FRP composites at elevated temperatures. In this paper, the effect of temperature on the mechanical properties of FRP bars was investigated. Three types of FRP bar were tested: BFRP, HFRP in which 25% of basalt fibers were replaced with carbon fibers and nHFRP in which epoxy resin was additionally modified with a nanosilica admixture. The mechanical properties were determined using ASTM standard testing for transverse shear strength. The tests were performed at -20°C, +20°C, +80°C for three diameters of each types of bar.
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Gailitis, Rihards, Andina Sprince, Tomass Kozlovksis, Leonids Pakrastins, and Viktorija Volkova. "Impact of Polypropylene, Steel, and PVA Fibre Reinforcement on Geopolymer Composite Creep and Shrinkage Deformations." Journal of Physics: Conference Series 2423, no. 1 (January 1, 2023): 012030. http://dx.doi.org/10.1088/1742-6596/2423/1/012030.
Повний текст джерелаАнотація:
Abstract For the last 40 years, there has been increased interest in geopolymer composite development and its mechanical properties. In the last decades, there have been cases when geopolymer composites have been used for civil engineering purposes, such as buildings and infrastructure projects. The main benefit of geopolymer binder usage is that it has a smaller impact on the environment than the Portland cement binder. Emissions caused by geopolymer manufacturing are at least two times less than emissions caused by Portland cement manufacturing. As geopolymer polymerization requires elevated temperature, it also has a significant moisture evaporation effect that further increases shrinkage. It can lead to increased cracking and reduced service life of the structures. Due to this concern, for long-term strain reduction, such as plastic and drying shrinkage and creep, fibre reinforcement is added to constrain the development of stresses in the material. This research aims to determine how different fibre reinforcements would impact geopolymer composites creep and shrinkage strains. Specimens for long-term property testing purposes were prepared with 1% of steel fibres, 1% polypropylene fibres (PP), 0.5% steel and 0.5% polyvinyl alcohol fibres, 5% PP fibres, and without fibres (plain geopolymer). The lowest creep strains are 5% PP fibre specimens, followed by 1% PP fibre, plain, 0.5% steel fibre and 0.5% PVA fibre, and 1% steel fibre specimens. The lowest specific creep is to 5% PP fibre reinforced specimens closely followed by 1% PP fibre followed by 0.5% steel and 0.5% PVA fibre, plain and 1% steel fibre reinforced composites. Specimens with 0.5% steel and 0.5 PVA fibre showed the highest compressive strength, followed by 1% PP fibre specimens, plain specimens, 1% steel fibre, and 5% PP fibre reinforced specimens. Only specimens with 1% PP fibre and 0.5% steel, and a 0.5% PVA fibre inclusion showed improved mechanical properties. Geopolymer concrete mix with 1% PP fibre inclusion and 0.5% steel and 0.5% PVA fibre inclusion have a 4.7% and 11.3% higher compressive strength. All the other fibre inclusion into mixes showed significant decreases in mechanical properties.
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Jain, Amit, and Bora Gencturk. "Multiphysics and Multiscale Modeling of Coupled Transport of Chloride Ions in Concrete." Materials 14, no. 4 (February 13, 2021): 885. http://dx.doi.org/10.3390/ma14040885.
Повний текст джерелаАнотація:
Chloride ions (Cl−)-induced corrosion is one of the main degradation mechanisms in reinforced concrete (RC) structures. In most situations, the degradation initiates with the transport of Cl− from the surface of the concrete towards the reinforcing steel. The accumulation of Cl− at the steel-concrete interface could initiate reinforcement corrosion once a threshold Cl− concentration is achieved. An accurate numerical model of the Cl− transport in concrete is required to predict the corrosion initiation in RC structures. However, existing numerical models lack a representation of the heterogenous concrete microstructure resulting from the varying environmental conditions and the indirect effect of time dependent temperature and relative humidity (RH) on the water adsorption and Cl− binding isotherms. In this study, a numerical model is developed to study the coupled transport of Cl− with heat, RH and oxygen (O2) into the concrete. The modeling of the concrete microstructure is performed using the Virtual Cement and Concrete Testing Laboratory (VCCTL) code developed by the U.S. National Institute of Standards and Technology (NIST). The concept of equivalent maturation time is utilized to eliminate the limitation of simulating concrete microstructure using VCCTL in specific environmental conditions such as adiabatic. Thus, a time-dependent concrete microstructure, which depends on the hydration reactions coupled with the temperature and RH of the environment, is achieved to study the Cl− transport. Additionally, Cl− binding isotherms, which are a function of the pH of the concrete pore solution, Cl− concentration, and weight fraction of mono-sulfate aluminate (AFm) and calcium-silicate-hydrate (C-S-H), obtained from an experimental study by the same authors are utilized to account for the Cl− binding of cement hydration products. The temperature dependent RH diffusion was considered to account for the transport of Cl− with moisture transport. The temperature and RH diffusion in the concrete domain, composite theory, and Cl− binding and water adsorption isotherms are used in combination, to estimate the ensuing Cl− diffusion field within the concrete. The coupled transport process of heat, RH, Cl−, and O2 is implemented in the Multiphysics Object-Oriented Simulation Environment (MOOSE) developed by the U.S. Idaho National Laboratory (INL). The model was verified and validated using data from multiple experimental studies with different concrete mixture proportions, curing durations, and environmental conditions. Additionally, a sensitivity analysis was performed to identify that the water-to-cement (w/c) ratio, the exposure duration, the boundary conditions: temperature, RH, surface Cl− concentration, Cl− diffusion coefficient in the capillary water, and the critical RH are the important parameters that govern the Cl− transport in RC structures. In a case study, the capabilities of the developed numerical model are demonstrated by studying the complex 2D diffusion of Cl− in a RC beam located in two different climatic regions: warm and humid weather in Galveston, Texas, and cold and dry weather in North Minnesota, Minnesota, subjected to time varying temperature, RH, and surface Cl− concentrations.
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Martynov, Gleb V., Daria E. Monastyreva, Elena A. Morina, and Aleksey I. Makarov. "Stress-strain state of fiberglass in conditions of climatic aging." Vestnik MGSU, no. 12 (December 2018): 1509–23. http://dx.doi.org/10.22227/1997-0935.2018.12.1509-1523.
Повний текст джерелаАнотація:
Introduction. Were investigated samples of fiberglass with the aim of its effective use in construction in the long term. Fiberglass is considered one of the most versatile and durable materials among polymer composite materials, however, and it is subject to destruction. It is known that one of the main reasons for reducing the specified characteristics and material properties is operational. At the design stage, it is necessary to determine the most reliable and economical materials used and, accordingly, be sufficiently aware of their strength and durability. Thus, in order to avoid the destruction of the material, as well as significantly enhance and prolong its service life, it is necessary to be aware of how exactly the properties of the material change over time. Regarding reinforced concrete, wood, brick and steel fiberglass is used in construction recently. This means that while the service life of the list of the most common materials in construction is known to a sufficient extent, manufacturers do not dare to use fiberglass as a material for critical structures. This occurs because changes in its characteristics, depending on operational factors, are not sufficiently studied for intervals exceeding 4-5 years of operation. Materials and methods. During the work, samples of fiberglass SPPS with a longitudinal and transverse arrangement of fiberglass were tested for climatic aging in a climatic chamber for 5 cycles simulating 5 years of material operation. All samples were subjected to tensile testing on a tensile testing machine R-5. Results. Destructive stresses were determined, calculations were carried out and elastic and strength characteristics of the samples were analyzed. On the basis of the obtained results, an analysis was carried out, conclusions were formulated about the use of fiberglass in the construction in the long term, as well as the influence of such operational factors as moisture, positive and negative temperatures, and ultraviolet radiation on the properties of fiberglass with a different arrangement of fiberglass. Conclusions. Found that the destructive stresses of fiberglass are significantly reduced during the first two years of operation, which must be considered when choosing fiberglass with the stated characteristics. Ultraviolet does not have a significant effect on the elastic-strength properties of the material, while during operat
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Hou, Hetao, Weiqi Fu, Canxing Qiu, Jirun Cheng, Zhe Qu, Wencan Zhu, and Tianxiang Ma. "Effect of axial compression ratio on concrete-filled steel tube composite shear wall." Advances in Structural Engineering 22, no. 3 (August 28, 2018): 656–69. http://dx.doi.org/10.1177/1369433218796407.
Повний текст джерелаАнотація:
This study proposes a new type of shear wall, namely, the concrete-filled steel tube composite shear wall, for high performance seismic force resisting structures. In order to study the seismic behavior of concrete-filled steel tube composite shear wall, cyclic loading tests were conducted on three full-scale specimens. One conventional reinforced concrete shear wall was included in the testing program for comparison purpose. Regarding the seismic performance of the shear walls, the failure mode, deformation capacity, bearing capacity, ductility, hysteretic characteristics, and energy dissipation are key parameters in the analysis procedure. The testing results indicated that the bearing capacity, the ductility, and the energy dissipation of the concrete-filled steel tube composite shear walls are greater than that of conventional reinforced concrete shear walls. In addition, the influence of axial compression ratio on the seismic behavior of concrete-filled steel tube composite shear wall is also investigated. It was found that higher axial compression ratio leads to an increase in the bearing capacity of concrete-filled steel tube composite shear walls while a reduction in the ductility capacity.
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Lumingkewas, Riana Herlina, Akhmad Herman Yuwono, Sigit Pranowo Hadiwardoyo, and Dani Saparudin. "The Compressive Strength of Coconut Fibers Reinforced Nano Concrete Composite." Materials Science Forum 943 (January 2019): 105–10. http://dx.doi.org/10.4028/www.scientific.net/msf.943.105.
Повний текст джерелаАнотація:
The compressive strength of the concrete reviewed in this study uses nanosilica and coconut fibers. The addition of coconut fibers to concrete contributes to the construction of sustainable and environmentally friendly building materials. The testing method carried out physically and mechanically. Testing the compressive strength of the nanoconcrete composite with variations in the amount of nanosilica which substituted with cement. Using variations of nanosilica composition, namely 0%, 0.5%, 1%, 1.5%, and 2% added with coconut fiber to determine the effect of compressive strength from nanoconcrete composite. The results obtained are the optimal value of concrete compressive strength with nanosilica is the addition of 2% nanosilica, which increases 43% of standard concrete. Moreover, on concrete with the addition of nanosilica and the addition of coconut fibers 1% test results in concrete compressive strength which is optimal in the addition of 0.5% nanosilica, which is 58% increase from normal concrete. The conclusion of this study that the addition of nanosilica and reinforced with coconut fiber will increase the compressive strength of concrete, this is an excellent composite material to get environmentally friendly building materials using.
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Harbi, Nibras Abbas, and Amer F. Izzet. "Performance of Post-Fire Composite Prestressed Concrete Beam Topped with Reinforced Concrete Flange." Civil Engineering Journal 4, no. 7 (July 30, 2018): 1595. http://dx.doi.org/10.28991/cej-0309198.
Повний текст джерелаАнотація:
The performance of composite prestressed concrete beam topped with reinforced concrete flange structures in fire depends upon several factors, including the change in properties of the two different materials due to fire exposure and temperature distribution within the composition of the composite members of the structure. The present experimental work included casting of 12 identical simply supported prestressed concrete beams grouped into 3 categories, depending on the strength of the top reinforced concrete deck slab (20, 30, and 40 MPa). They were connected together by using shear connector reinforcements. To simulate the real practical fire disasters, 3 composite prestressed concrete beams from each group were exposed to high temperature flame of 300, 500, and 700°C, and the remaining beams were left without burning as reference specimens. Then, the burned beams were cooled gradually by leaving them at an ambient lab condition, after which the specimens were loaded until failure to study the effect of temperature on the residual beams serviceability, to determine the ultimate load-carrying capacity of each specimen in comparison with unburned reference beam, and to find the limit of the temperature for a full composite section to remain composite. It was found that the exposure to fire temperature increased the camber of composite beam at all periods of the burning and cooling cycle as well as the residual camber, along with reduction in beam stiffness and the modulus of elasticity of concrete in addition to decrease in the load-carrying capacity.
Частини книг з теми "Composite reinforced concrete Effect of temperature on Testing"
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"Finite element code for composite beam element: Nonlinear analysis with temperature effect." In Nonlinear Finite Element Analysis of Composite and Reinforced Concrete Beams, 189–226. Elsevier, 2020. http://dx.doi.org/10.1016/b978-0-12-816899-8.09984-3.
Повний текст джерелаТези доповідей конференцій з теми "Composite reinforced concrete Effect of temperature on Testing"
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Mirza, Olivia, Andrew Talos, Matthew Hennessy, and Brendan Kirkland. "Behaviour and Design of Composite Steel and Precast Concrete Transom for Railway Bridges Application." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.6993.
Повний текст джерелаАнотація:
Currently most railway bridges in Australia require the replacement of the timber transoms that reside in the railway system. Composite steel and precast reinforced concrete transoms have been proposed as the replacement for the current timber counterparts. This paper outlines the structural benefits of composite steel-concrete transoms for ballastless tracks when retrofitted to existing railway steel bridges. However, in existing studies, it is found that there is little investigation into the effect of derailment loading on reinforced concrete transoms. Therefore, this paper provides an investigation of derailment impact loading on precast reinforced concrete transoms. The paper herein investigates the derailment impact loading of a train through experimental testing and numerical analysis of conventional reinforced concrete transoms. The paper also evaluates the potential use of 3 different shear connectors; welded shear studs, Lindapter bolts and Ajax bolts. The results of the experimental tests and finite element models are used to determine whether each transom is a viable option for the replacement of the current timber transoms on the existing bridges in Australia and whether they provide a stronger and longer lasting solution to the current transom problem.
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Han, Lin-Han, and Kan Zhou. "Fire performance of concrete-encased CFST columns and beam-column joints." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.6927.
Повний текст джерелаАнотація:
Concrete-encased CFST (concrete filled steel tube) structure is a type of composite structure featuring an inner CFST component and an outer reinforced concrete (RC) component. They are gaining popularity in high-rise buildings and large-span buildings in China nowadays. To date, the behaviour of concrete-encased CFST structures at ambient temperature has been investigated, but their fire performance has seldom been addressed, including the performance in fire and after exposure to fire. This paper summarizes the fire test results of concrete-encased CFST columns and beam-column joints. The cruciform beam-column joint was composed of one continuous concrete-encased CFST column and two cantilevered reinforced concrete (RC) beams. These specimens were subjected to a combined effect of load and full-range fire. The test procedure included four phases, i.e. a loading phase at ambient temperature, a standard fire exposure phase with constant load applied, a sequential cooling phase and a postfire loading phase. The main findings are presented and analysed. Two types of failure were identified, i.e. the failure during fire exposure and the failure during postfire loading. Global buckling failure was observed for all the column specimens. The column specimens with common load ratios achieved high fire ratings without additional fire protection. The concrete-encased CFST columns also retained high postfire residual strength. As for the joint members, beam failure was observed in all cases. The measured temperature-time history and deformation-time history are also presented and discussed. For both the column and joint specimens, the deformation over the cooling phase was significantly greater than that in the standard fire exposure phase.
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Longbiao, Li. "Temperature-Dependent Fatigue Damage Evolution of Fiber-Reinforced Ceramic-Matrix Composites." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-14144.
Повний текст джерелаАнотація:
Abstract In this paper, the temperature-dependent fatigue damage evolution of fiber-reinforced ceramic-matrix composites (CMCs) is investigated. The fatigue loading/unloading constitutive model considering the effect of temperature is developed based on the damage mechanisms of matrix cracking, interface debonding, and repeated sliding between the fiber and the matrix. The relationships between the fatigue loading/unloading hysteresis loops, testing temperature, applied cycle number, peak stress, and fiber/matrix interface debonding and sliding are established. The evolution of fatigue loading/unloading hysteresis loops, interface debonding and sliding length with applied cycle number is analyzed. The effects of temperature, peak stress level, applied cycle number, interface shear stress, and interface debonding energy on the fatigue damage evolution are discussed based on the developed temperature-dependent fatigue loading/unloading constitutive model. The experimental fatigue damage evolution of SiC/SiC composite at 600°C, 800°C, and 1000°C in inert atmosphere, 1000°C in air and in steam atmosphere, and 1300°C in air atmosphere are predicted. The interface shear stress of SiC/SiC composite decreases with temperature, and the degradation rate of interface shear stress increases with temperature.
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Nazaripoor, Hadi, John Sunny, Ahmed Hammami, and Pierre Mertiny. "Mechanical Performance of Aged Long Fibers: Direct Water Exposure and Temperature Effect." In ASME 2022 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/pvp2022-83931.
Повний текст джерелаАнотація:
Abstract Long fiber-reinforced composite materials consist of continuous fibers with high strength and modulus embedded in either a thermoset or thermoplastic matrix. The resulting composite material provides a combination of properties that cannot be achieved with either of the constituents acting alone. In composite structures, fibers are the primary load-carrying element, whereas the matrix transfers stress to and between the fibers while protecting them from adverse environmental conditions and mechanical damages. While thermosetting matrices provide a high level of protection against water permeation, exposure to moisture may still be significant in certain thermoplastics. Therefore, the effect of moisture on the reinforcing elements and the degradation rate may be considerable. The presented study investigated the effects of environmental aging conditions on different commercially available continuous fibers, i.e., glass fiber, carbon fiber, and basalt fiber. The fibers were soaked in water at room and elevated temperature to investigate the degradation mechanisms and, ultimately, the mechanical performance of the fibers. Mechanical testing was performed with wet fibers and dried fibers after aging. In addition, scanning electron microscopy was employed to explore the responsible mechanism for fiber degradation by environmental aging.
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Kibsey, Mitch, and Xiao Huang. "Development and Oxidation Test of Metal Mesh Reinforced Ceramic Composite Material." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-36827.
Повний текст джерелаАнотація:
As part of an ongoing research development at Carleton University in ceramic matrix composites (CMCs) for high-temperature gas turbine applications, it was recognized that the performance of an oxide matrix could be improved by incorporating a metal reinforcement material. For this reason, a low cost CMC was created by reinforcing a yttria-stabilized zirconia (7YSZ) ceramic matrix with a Hastelloy X (HX) wire mesh. The CMC was manufactured by coating the HX mesh with a NiCrAlY bond coat, and then 7YSZ ceramic matrix, both using plasma spraying. The bond coat was employed to improve bonding and also to act as an oxygen diffusion barrier. In order to evaluate the performance of the HX/7YSZ composite at high temperatures, isothermal and cyclic oxidation tests were carried out for 1000 hours at 1050°C. The results showed that oxidation resistance was improved by vacuum heat treatment prior to testing due to the formation of stable thermally grown oxides (TGO) on the NiCrAlY bond coat. In the cyclic oxidation test, differences in thermal expansion coefficients caused cracking at interfaces between mesh/bond coat and bond coat/7YSZ. Minimizing the effect of thermal expansion by better material combination, as well as modifying manufacturing methods will allow for improved performance of metal mesh reinforced CMCs.
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BANIK, ARNOB, M. H. KHAN, and K. T. TAN. "IMPACT PERFORMANCE COMPARISON OF FIBER REINFORCED COMPOSITE SANDWICH STRUCTURES IN ARCTIC CONDITION." In Proceedings for the American Society for Composites-Thirty Seventh Technical Conference. Destech Publications, Inc., 2022. http://dx.doi.org/10.12783/asc37/36380.
Повний текст джерелаАнотація:
About 40% of sea ice-covered areas have been reduced over the last three decades due to the effect of global warming. The Northern Sea route has been considered as a more effective, quicker, and economical sea route for marine vessels. But it is not safe to operate in such a cold and harsh environment due to the potential risk of collision with ice chunks, resulting in damages in the marine structures. It is therefore important to understand the behavior of marine composites at low temperatures, with the overarching goal that leads to improved design for marine structures and materials that can operate safely and effectively in the Arctic environment. This study investigates the low-velocity impact performance and damage mechanisms of woven carbon fiber reinforced polymer (CFRP), glass fiber reinforced polymer (GFRP), and carbon-glass fiber hybrid face sheets sandwich panel at both room temperature (23 °C) and low temperature (-70 °C) to mimic the Arctic environment. A series of low-velocity impact tests (3.46 m/s and 4.92 m/s) is performed at 15 J and 30 J energy using a drop tower testing machine. A relative comparison of the impact response due to different face sheet materials is presented in terms of force, displacement, and energy. Force-time and force-displacement plots show that GFRP sandwich composites have the highest damage initiation force and peak force values across different temperatures and impact energies. Furthermore, the lowest energy absorption for GFRP composites is found responsible for the least impact-induced damage. X-ray microcomputed tomography reveals severe fiber breakage on the compression side of CFRP sandwich panel and back face spitting at both temperatures for 30 J impacts. By replacing carbon fibers with glass fibers, the damage mechanism switches from fiber breakage to delamination as the dominant failure mode. The findings from this work will aid in a better understanding of the impact failure modes of composite sandwich structures at extremely low-temperature conditions.
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Ainsworth, Stephen D., and Robert A. Latour. "Design Optimization of a Composite Splint Material for Strength and Thermoformability." In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-0332.
Повний текст джерелаАнотація:
Abstract The development of a short fiber reinforced, low temperature thermoplastic splint material has potential to improve the ease, cost and efficiency of splinting and casting musculoskeletal problems. Design optimization of the fiber/matrix system is a key step in the development process of this new material. The tensile strength, flexural strength, and elastic moduli were found for 2-D randomly oriented short E-glass fiber reinforced polycaprolactone at both room temperature and at 170°F. The effect of fiber length and fiber volume fraction on the previously mentioned properties were studied by testing a range of fiber volume fractions (0.0 to 0.10) with fiber lengths of 3 mm and 7 mm. The results of this study show potential for increasing strength and rigidity of the low temperature thermoplastic through fiber reinforcement, while maintaining some degree of thermoformability.
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Park, Seungbae, Soonwan Chung, Harold Ackler, and Sandeep Makhar. "Viscoelastic Material Properties of SU-8 and Carbon-Nanotube-Reinforced SU-8 Materials." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-16062.
Повний текст джерелаАнотація:
The viscoelastic material properties of SU-8 and carbon nanotube-reinforced SU-8 composite material are characterized by tensile testing. Dogbone samples of 0.1mm thickness are prepared by micro-fabrication process, which is composed of spin coat, soft bake, expose, and post exposure bake. To fabricate CNT polymer composite, carbon nano-tube of 0.2wt% is mixed with SU-8. To observe the effect of applied strain rate and temperature on Young's modulus and Poisson's ratio, strain rate is varied from 5×10-5 to 2.5×10-4 (/sec) at elevated temperatures in the range of 25 to 200°C. Since the viscoelastic material properties are important in polymer, creep, stress relaxation and dynamic mechanical analyses are performed at elevated temperatures. The viscoelastic material properties of SU-8 and CNT-reinforced SU-8 composite are compared, and the mechanical reliability of these polymers in MEMS applications is discussed.
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Arhami, M., F. Sarioglu, and A. Kalkanli. "Effect of Heat-Treatment and Reinforcement With Silicon Carbide on the Microstructure and Mechanical Properties of AlFeVSi Alloy." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42073.
Повний текст джерелаАнотація:
The aging response of Al-Fe-V-Si composite was compared with the un-reinforced alloy. The effects of solutionizing time, alloying element and SiC reinforcement on the age hardening response, microstructure and mechanical properties of these alloy and its composites was also investigated. The study was performed by T6 heat treatment at three different solutionizing times. Room temperature tensile testing was conducted for peak aged specimens to determine the effect of this heat treatment on the strength of squeezed cast un-reinforced and reinforced Al-Fe-V-Si alloy with SiC particles. The presence of SiC particles accelerated the aging kinetics of the composites compared to the unreinforced alloys. The time to reach peak age hardness was decreased by addition of SiCp. Mainly two different Fe-intermetallics; small α-Al7(Fe, V)3Si and large β-Al18Fe11Si phases were present in the system studied. The fracture surfaces of composites revealed decohesion of SiC particles from the matrix and cracking of needle like-β intermetallics was observed.
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Gupta, V., R. Knight, M. Ivosevic, R. A. Cairncross, T. E. Twardowski, and S. Taghizadeh. "Properties of HVOF Sprayed Multi-Scale Polymer/Silica Composite Coatings." In ITSC2005, edited by E. Lugscheider. Verlag für Schweißen und verwandte Verfahren DVS-Verlag GmbH, 2005. http://dx.doi.org/10.31399/asm.cp.itsc2005p0951.
Повний текст джерелаАнотація:
Abstract The high velocity oxy-fuel (HVOF) combustion spray process has been demonstrated to be a suitable technique for the deposition of nano-reinforced polymer matrix composite coatings by controlling both the particle dwell time and the substrate temperature. HVOF-sprayed polymer matrix composites incorporating reinforcements with size scales ranging from 7 nm to 100 µm are being studied to bridge between the nano and conventional scale regimes. Microstructural characterization has been used to characterize the dispersion and distribution of the ceramic reinforcements within the polymer matrix. The effect of particle size distribution on reinforcement dispersion and distribution has been studied, and the influence of substrate temperature on coating adhesion has also been investigated. Changes in crystallinity, as determined by Differential Scanning Calorimetry (DSC), are being correlated to coating microstructure, reinforcement loading and process parameter variations. Results of optical and scanning electron microscopy, scratch testing and DSC characterization of the feedstock materials and sprayed coatings are presented. Coatings of nominal 60 µm Nylon 11 with 10 vol. % of nano and micron size hydrophilic silica reinforcements exhibited a ~22 % improvements in scratch resistance compared to pure Nylon 11 coatings. An ~15 % improvement in scratch resistance was obtained for coatings containing 10 vol. % nano scale hydrophilic silica reinforcement.