Journal articles: 'Composite materials – Moisture'

1

Tsotsis, T. K. "Effects of Sub-Freezing Temperatures on Graphite/Epoxy Composite Materials." Journal of Engineering Materials and Technology 111, no. 4 (October 1, 1989): 438–39. http://dx.doi.org/10.1115/1.3226492.

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Moisture in composite materials has been the subject of considerable interest in the past decade. Many studies have shown that moisture directly causes damage in graphite/epoxy composite materials. With the increasing use of such composites in various environments, an assessment of the effects of sub-freezing and/or cryogenic temperatures on composites containing moisture is needed. This article presents a summary of these effects and demonstrates that reductions in strength at low temperatures are not due to the formation of ice crystals, but instead are due to changes in the residual stresses caused by absorbed moisture.

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Fan, Yansheng, Min Li, Yizhuo Gu, Shaokai Wang, and Yanjie Wang. "Effects of Z-pin on moisture absorption property and damage mode under flexural load for carbon fiber composite." Science and Engineering of Composite Materials 29, no. 1 (January 1, 2022): 206–14. http://dx.doi.org/10.1515/secm-2022-0020.

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Abstract The effect of carbon fiber Z-pin on carbon fiber composite under moisture condition with and without flexural load was investigated in this work. Moisture absorption property and crack propagation of carbon fiber reinforced epoxy matrix composite and Z-pinned composite were evaluated under moisture only and moisture-coupled load conditions. The moisture property was evaluated by moisture content and microscopic morphology obtained using X-ray micro-computed tomography (X-ray μCT). The microstructures inside composites and Z-pinned composites after moisture conditions and three-point flexural test were detected using X-ray μCT and optical microscope. It illustrates that the moisture content of Z-pinned composites is higher due to the rich-resin pocket brought by the implantation of Z-pin. The cracks are obvious inside Z-pinned composites after moisture-coupled load conditions. It is attributed to the implantation of each pin which is the weak point for stress concentration and crack formation. Failure morphologies on the surface of composites and Z-pinned composites are different under different moisture conditions. Less macro-interlayer cracks are detected on the surface of Z-pinned composites, and plenty of microcracks initiating from pins are observed.

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Sateesh, N., P. Sampath Rao, D. V. Ravishanker, and K. Satyanarayana. "Effect of Moisture on GFRP Composite Materials." Materials Today: Proceedings 2, no. 4-5 (2015): 2902–8. http://dx.doi.org/10.1016/j.matpr.2015.07.252.

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Barakhov, V. I., V. V. Chernyaev, and V. I. Goncharov. "Random migration of moisture in composite materials." Journal of Engineering Physics 59, no. 5 (November 1990): 1427–32. http://dx.doi.org/10.1007/bf00872962.

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Youssef, G., S. Fréour, and F. Jacquemin. "Stress-dependent Moisture Diffusion in Composite Materials." Journal of Composite Materials 43, no. 15 (June 8, 2009): 1621–37. http://dx.doi.org/10.1177/0021998309339222.

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Perisic, Srdjan, Marija Vuksanovic, Milos Petrovic, Andjela Radisavljevic, Aleksandar Grujic, Radmila Jancic-Heinemann, and Vesna Radojevic. "Impact of alumina particles on the morphology and mechanics of hybrid wood plastic composite materials." Science of Sintering 51, no. 1 (2019): 115–24. http://dx.doi.org/10.2298/sos1901115p.

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Hybrid composite panels of Wood-Plastic Composites (WPC) consisting of wood and poly (methyl methacrylate) (PMMA) were reinforced with alumina particles and made by ?hot pressing? method. Alumina-based particles were made by sol-gel technique. The particles were characterized by the X-ray diffraction (XRD). The resulting alumina particles were modified with (3mercaptopropyl) trimethoxysilane (MPTMS), in order to obtain better mechanical properties of the composite relative to the composite with unmodified alumina particles. The aim of this work was to study the influence of composite structure and the moisture absorption on bending and the impact properties of the hybrid composite. The bending and impact tests revealed that modulus of elasticity and absorbed energy of deformation increased with modification of alumina and slightly decrease after moisture absorption.

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Sorrentino, Romualdo, Luigi Di Palma, Michele Inverno, and Paolo Vernillo. "An Impedance Measurement Technique for Composite Materials Moisture Level Detection Devoted to Health Monitoring in Aeronautics." Journal of Composites Science 3, no. 3 (August 1, 2019): 76. http://dx.doi.org/10.3390/jcs3030076.

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The current design practice of composite material aeronautical structures imposes the use of knock-down structural material allowables to take into account the high sensitivity to environmental exposure (i.e., moisture, temperature, damages). The “moisture derating factor” comes from specific mechanical test campaign and drastically reduces the advantage of using such materials; but the continuous monitoring of the moisture content of the structure could enable the use of higher design allowables. In the framework of FUSIMCO (Work developed within the frame of the Project FUSIMCO-FUSoliera Ibrida Metallo COmposito-co-financed by MIUR-Italian Ministry of Research with DAC-Campania Aerospace District as beneficiary and Leonardo Company-Aerostructure Division as “prime” partner) project, the aim of this study is to verify the effectiveness of the impedance measurement method as a health-monitoring tool to evaluate the moisture quantity absorbed by an aeronautical composite structure. The method is based on the idea that a composite laminate can be associated with an equivalent electric circuit (EEC). Some electrical characteristics of this EEC can be associated to the moisture content of the laminate. A simple EEC model, mainly capacitive, was used. A frequency sweep was the electric stimulus signal of some electrodes, glued onto the specimens to investigate the EEC parameters variation with respect to the induced moisture content variation (gravimetrically determined). The study confirmed the possibility of effectively using the impedance measurement method as a health-monitoring tool for moisture content evaluation of a composite laminate.

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Shen, Bing, HongJun Liu, Shengli Lv, Zheng Li, and Wen Cheng. "Acid Aging of CFRP Composite Materials for Solar UAV Structure." International Journal of Aerospace Engineering 2021 (October 15, 2021): 1–12. http://dx.doi.org/10.1155/2021/1664847.

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The purpose of this investigation is to study the performance degradation mechanism of CRRP composite materials used in the structure of a solar UAV under acid rain environment and to provide references for the structural design of the solar UAV. An aging test was designed according to the actual working conditions of the solar unmanned aerial vehicle and was carried out by continuously immersing the composite material in both deionized water and an acidic solution with a pH of 2.0 at 60°C. The mechanical behavior of the composites was studied through a three-point bending test. The results showed that after 120 days of aging test, the composite material exhibits different characteristics in the two conditions. The composite material under the hygrothermal conditions finally reached the equilibrium moisture absorption content of 1.07%, and the flexural strength decreased by 8.77%. The composite material under acidic conditions deviated from the Fick behavior in the final stage of the test, and the final moisture content was 2.88%, and the bending strength decreased by 26.43%. Several typical empirical models were analyzed, and a hyperbolic tangent function empirical model with moisture content as the main variable was used to predict the CFRP flexural strength degradation process, and good results were obtained. The effect of aging conditions on the microstructure of composite materials was observed by SEM, and the aging mechanism of composite materials was analyzed. The corrosion of the polymer matrix and the debonding of the fiber/matrix interface are the root causes of the performance degradation of composite materials.

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Mensitieri, G., M. A. Del Nobile, A. Apicella, and L. Nicolais. "Moisture-Matrix Interactions in Polymer Based Composite Materials." Revue de l'Institut Français du Pétrole 50, no. 4 (July 1995): 551–71. http://dx.doi.org/10.2516/ogst:1995034.

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10

Wang, John Z., David A. Dillard, Michael P. Wolcott, Frederick A. Kamke, and Garth L. Wilkes. "Transient Moisture Effects in Fibers and Composite Materials." Journal of Composite Materials 24, no. 9 (September 1990): 994–1009. http://dx.doi.org/10.1177/002199839002400906.

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11

Gueribiz, D., F. Jacquemin, and S. Fréour. "A moisture diffusion coupled model for composite materials." European Journal of Mechanics - A/Solids 42 (November 2013): 81–89. http://dx.doi.org/10.1016/j.euromechsol.2013.04.008.

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Jin, Ping, De Wang, and Xiao Ming Tan. "Analysis of Moisture Distribution within Composite Materials in Hygrothermal Environment." Advanced Materials Research 873 (December 2013): 401–5. http://dx.doi.org/10.4028/www.scientific.net/amr.873.401.

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The moisture absorption behavior of CCF300/BA9916 composites in 70°C distilled water was investigated. Depending on the moisture absorption experiments, the moisture diffusivity and solubility were gained for FEM analysis. The experiments results show that the moisture absorption behavior of CCF300/BA9916 composites basically conforms the Fickians second law. The simulation results were coincided with the experimental data, the long-term absorption behavior and moisture distribution concentrations within the specimen were obtained.

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Potapova, Ekaterina, Ekaterina Dmitrieva, Aung Kyaw Nian, and Elena Tsvetkova. "Gypsum Composite Reinforced with Polymer Fibers." Key Engineering Materials 910 (February 15, 2022): 880–86. http://dx.doi.org/10.4028/p-dgyem5.

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Composite gypsum binders harden quickly, gain strength quickly and have positive environmental properties. Moreover, they are characterized by increased moisture resistance, which significantly expands the field of application of such gypsum materials. Dispersed reinforcement of composite gypsum binders with polypropylene fibers makes it possible to obtain composites characterized by high performance properties. On basis of developed compositions of gypsum-cement-pozzolanic and composite gypsum binders with polymer fibers, gypsum composites have been created, characterized by increased strength, water resistance, frost and corrosion resistance.

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VIZENTIN, Goran, and Goran VUKELIC. "Degradation and Damage of Composite Materials in Marine Environment." Materials Science 26, no. 3 (February 27, 2020): 337–42. http://dx.doi.org/10.5755/j01.ms.26.3.22950.

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IIn spite the fact that composite materials have been in use in the maritime sector for over a half of century, classification societies regulations tend to limit the usage of composites at the larger scale. One of the reasons for such strict class rules is a lack of comprehensive analytical and numerical models representing the behaviour of composites in the sea environment. Understanding the process of degradation and damage of composite materials assisted by sea environment a crucial step in building such a model. This paper aims to give a critical review of the research advancements in assessments of the sea environment influence on the degradation of mechanical properties of composites with a special emphasis on developed models of processes containing water and moisture entering composite inner structure. The list of major references in the last five years is given and suggestions for future research are discussed.

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DIANA-IRINEL, Băilă, Păcurar RAZVAN, and Păcurar ANCU?A. "Moisture Absorption Behavior of CP5 Composite Materials Used in Industry." Eurasia Proceedings of Science Technology Engineering and Mathematics 18 (October 20, 2022): 55–63. http://dx.doi.org/10.55549/epstem.1192332.

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In engineering practice, perhaps the most interesting aspect of woodworking deals with the relationship between wood and moisture. The plywood composite presents hygroscopicity characteristic, as the wood and reaction almost like a sponge, will gain or lose moisture from the air based upon the conditions of the surrounding environment. When the tree is in the green state, is first felled, it contains a very large amount of moisture existing in two different forms: as free water that is contained as liquid in the pores or vessels of the wood itself and as bound water, trapped within the cell walls. After that the wood is exposed to the air and immediately loose free water and the wood does not contract or otherwise change in dimension, it is in the state of drying and it is called the fiber saturation point. The moisture content in each piece of CP5 composite material is expressed as a percentage of the weight of the water and oven-dry weight of CP5 composite material. The moisture absorption depends on the wood type, density of wood and it is influenced by the environmental temperature, this is an aspect very important in the furniture industry. The moisture absorption test is generally used for quality control purposes and to measure the degradation of the quality for the wood and composite materials.

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Xu, Peng Fei, Zhi Wen Hu, Zhi Qin Peng, Dun Huang, Ning Yu, and Qing Qing Yao. "Preparation for Spherical Humidity Control Composite Materials and their Humidity Control Properties." Advanced Materials Research 631-632 (January 2013): 442–46. http://dx.doi.org/10.4028/www.scientific.net/amr.631-632.442.

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A spherical humidity control composite material with excellent humidity control performances has been prepared by twice foaming method. The composite comprises a natural polymer derivative (KGM), a porous natural mineral (Halloysite) and an Sodium polyacrylate (PAAS). It has high capacity for moisture adsorption, fast response to humidity changes, and small range for equilibrium humidity control. The moisture adsorption content of the composite material is 1.10 (g/g) of its own weight. The moisture absorption rate is 0.3948 (g/7h•g-1), and moisture desorption rate is 0.4682 (g/7h•g-1). The composite material has an equilibrium humidity control ranging from 50%RH to 53%RH. It can reach to the equilibrium levels within 60 minutes. It is suitable for maintaining a proper micro-environment for places such as museums or galleries.

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Way, Daniel, Frederick A. Kamke, and Arijit Sinha. "Moisture Transport in Wood-Based Structural Panels under Transient Hygroscopic Conditions." Forest Products Journal 70, no. 3 (January 1, 2020): 283–92. http://dx.doi.org/10.13073/fpj-d-20-00012.

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Abstract Development of moisture gradients within wood and wood-based composites can result in irreversible moisture-induced damage. Accelerated weathering (AW), generally employing harsh environmental conditions, is a common tool for assessing moisture durability of wood composite products. Use of milder AW conditions, such as cyclic changes in relative humidity (RH), may be of interest to the wood-based composites industry in assessing moisture durability under more realistic conditions. The primary objective of this study was to determine whether moisture profile development in oriented strand board and plywood during cyclic RH changes could be reasonably predicted with a simple moisture transport model, which may be practical for wood-based composite industry members seeking to develop new AW protocols. The diffusion model based on Fick's second law with empirically determined moisture transport parameters fits the experimental data reasonably well for the purpose of screening RH parameters.

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Pang, C., R. Shanks, K. Ing, and F. Daver. "Plasticised cellulose acetate-natural fibre composite." World Journal of Engineering 10, no. 5 (October 1, 2013): 405–10. http://dx.doi.org/10.1260/1708-5284.10.5.405.

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Due to positive impact on the environment, biodegradable composite materials are of growing interest. This study used cellulose acetate, a derivative of cellulose, as the matrix for its solubility and flexibility. Kenaf composites have been used in furniture, ceiling panels, and fences. The aim is to prepare composites with plasticized cellulose acetate and natural fibre. The kenaf fibres were surface treated to remove impurities, in particular, hemicellulose, wax, and lignin. Chopped kenaf was added to dissolve cellulose acetate and cast on a Petri dish. After solvent has evaporated, the composite was compression moulded. The thermal and mechanical properties of the kenaf cellulose acetate composite were characterised. From thermogravimetry, the composites were shown to be stable until moisture began evaporating. As a hydrophilic material, cellulose is sensitive to moisture. The mechanical properties of the composites were analysed under high humidity. Dynamic mechanical analysis showed that these properties changed slightly with humidity.

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Moudood, Abdul, Anisur Rahman, Andreas Öchsner, Md Mainul Islam, Mohammad Yeakub Ali, and Gaston Francucci. "Effects of Different Relative Humidities on Flax Fibers prior to Manufacturing Their Composites Based on the Shear Response." Advances in Materials Science and Engineering 2020 (August 3, 2020): 1–7. http://dx.doi.org/10.1155/2020/4785970.

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The moisture absorption behavior of flax fiber-reinforced epoxy composites is deliberated to be a serious issue. This property restricts their usage as outdoor engineering structures. Therefore, this study provides an investigation of moisture in flax fibers on the performance of the flax/epoxy composite materials based on their shear responses. The ±45° aligned flax fibers exposed to different relative humidities (RH) and the vacuum infusion process was used to manufacture the composite specimens. The optimum shear strength (40.25 ± 0.75 MPa) was found for the composites manufactured with 35% RH-conditioned flax fibers, but the shear modulus was reduced consistently with increasing RH values. Although shear strength was increased because of fiber swelling with increased moisture absorption rate until 35% RH environments with good microstructures, nonetheless, strength and modulus both started to decrease after this range. A very poor microstructure has been affirmed by the SEM images of the composite samples conditioned at 90% RH environments.

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Bouznik, V. M., E. V. Morozov, I. A. Avilova, and V. I. Volkov. "NMR Applications for Polymer Composite Materials Moisture Uptake Investigation." Applied Magnetic Resonance 47, no. 3 (January 6, 2016): 321–34. http://dx.doi.org/10.1007/s00723-015-0748-2.

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Alao, Percy Festus, Laetitia Marrot, Heikko Kallakas, Alar Just, Triinu Poltimäe, and Jaan Kers. "Effect of Hemp Fiber Surface Treatment on the Moisture/Water Resistance and Reaction to Fire of Reinforced PLA Composites." Materials 14, no. 15 (August 3, 2021): 4332. http://dx.doi.org/10.3390/ma14154332.

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The effects of surface pretreatment (water and alkali) and modification with silane on moisture sorption, water resistance, and reaction to fire of hemp fiber reinforced polylactic acid (PLA) composites at two fiber loading contents (30 and 50 wt.%) are investigated in this work. Moisture adsorption was evaluated at 30, 50, 75 and 95% relative humidity, and water resistance was determined after a 28-day immersion period. The cone calorimetry technique was used to investigate response to fire. The fiber surface treatment resulted in the removal of cell wall components, which increased fiber individualization and homogeneity as shown in scanning microscopic pictures of the composite cross-section. Although the improved fiber/matrix bonding increased the composite’s water resistance, the different fiber treatments generated equal moisture adsorption results for the 30 wt.% reinforced composites. Overall, increasing the fiber amount from 30 to 50 wt.% increased the composite sensitivity to moisture/water, mainly due to the availability of more hydroxyl groups and to the development of a higher pore volume, but fire protection improved due to a reduction in the rate of thermal degradation induced by the reduced PLA content. The new Oswin’s model predicted the composite adsorption isotherm well. The 30 wt.% alkali and silane treated hemp fiber composite had the lowest overall adsorption (9%) while the 50 wt.% variant produced the highest ignition temperature (181 ± 18 °C).

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Li, Mingyong, Xia Meng, and Qingyi Zhang. "Mixed Interlaminar Fracture Toughness and Durability of Composites under Humid and Hot Conditions." Journal of Nanomaterials 2022 (May 23, 2022): 1–12. http://dx.doi.org/10.1155/2022/2867239.

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Composite material is a new material prepared by several raw materials with different forms or properties through new processing methods. The composite not only maintains the advantages of the properties of each component but also can obtain the comprehensive properties that cannot be achieved by a single component through the complementarity and correlation of the properties of each component. The purpose of this paper is to study the effect of wet and hot conditions on the interlaminar fracture toughness and durability of composites. In this paper, the interlaminar fracture toughness and durability are studied, and the prediction and analysis method under wet and hot conditions is carried out. The effects of hot and humid conditions on interlaminar fracture toughness and durability were analyzed. The experimental results show that the longitudinal compressive strength of the unidirectional composite at 120°C and 1.00% moisture absorption is 29.53% lower than that at 20°C and 0.50% moisture absorption. Due to the high moisture absorption of aramid fiber, the longitudinal compressive strength of unidirectional aramid composite fiber will be significantly reduced in the humid and warm environment.

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Laurenzi, S., T. Albrizio, and M. Marchetti. "Modeling of Moisture Diffusion in Carbon Braided Composites." International Journal of Aerospace Engineering 2008 (2008): 1–10. http://dx.doi.org/10.1155/2008/294681.

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In this study, we develop a methodology based on finite element analysis to predict the weight gain of carbon braided composite materials exposed to moisture. The analysis was based on the analogy between thermal conduction and diffusion processes, which allowed for a commercial code for finite element analysis to be used. A detailed finite element model using a repetitive unit cell (RUC) was developed both for bundle and carbon braided composites. Conditioning tests were performed to estimate the diffusivity of both the resin and composite. When comparing numerical and experimental results, it was observed that the procedure introduces an average error of 20% and a maximum error of 31% if the RUC is assumed to be isotropic. On the other hand, the average error does not exceed 10% and the maximum error is less than 20% when the material is considered as orthotropic. The procedure is independent of the particular fiber architecture and can be extended to other composites.

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Sormunen, Petri, and Timo Kärki. "Compression Molded Thermoplastic Composites Entirely Made of Recycled Materials." Sustainability 11, no. 3 (January 25, 2019): 631. http://dx.doi.org/10.3390/su11030631.

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Recycled post-consumer high-density polyethylene pipe plastic was agglomerated into composite samples with wood, glass fiber, mineral wool, gypsum, and soapstone as recycled particulate fillers. The tensile strength, tensile modulus, impact strength, and hardness were the mechanical properties evaluated. Scanning electron microscopy was performed on the broken surfaces of tensile strength samples to study the interfacial interactions between the composite matrix and the filler materials. Heat build-up, water absorption, and thickness swelling were the physical properties measured from the composites. The addition of particulate fillers demonstrated the weakening of the tensile and impact strength but significantly improved the rigidity of the post-consumer plastic. The composites filled with minerals had mechanical properties comparable to compression molded wood plastic composites but higher resistance to moisture. A lack of hot-melt mixing affected the mechanical properties adversely.

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Crowe, Emma, Cameron Scott, Sarah Cameron, Jill H. Cundell, and James Davis. "Developing Wound Moisture Sensors: Opportunities and Challenges for Laser-Induced Graphene-Based Materials." Journal of Composites Science 6, no. 6 (June 16, 2022): 176. http://dx.doi.org/10.3390/jcs6060176.

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Recent advances in polymer composites have led to new, multifunctional wound dressings that can greatly improve healing processes, but assessing the moisture status of the underlying wound site still requires frequent visual inspection. Moisture is a key mediator in tissue regeneration and it has long been recognised that there is an opportunity for smart systems to provide quantitative information such that dressing selection can be optimised and nursing time prioritised. Composite technologies have a rich history in the development of moisture/humidity sensors but the challenges presented within the clinical context have been considerable. This review aims to train a spotlight on existing barriers and highlight how laser-induced graphene could lead to emerging material design strategies that could allow clinically acceptable systems to emerge.

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Пожилов-Несміян, Г. М., Н. П. Супрун, and Т. В. Гірна. "РОЗРОБКА АПЛІКАЦІЙНИХ ВКЛАДОК У ШВЕЙНІ ВИРОБИ ДЛЯ ЛЮДЕЙ З ІНВАЛІДНІСТЮ." Bulletin of the Kyiv National University of Technologies and Design. Technical Science Series 142, no. 1 (June 3, 2020): 63–70. http://dx.doi.org/10.30857/1813-6796.2020.1.6.

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Determination of the influence of raw material composition and structure of textile composite materials with fibrous carbon sorbent on their moisture absorption properties. Two-layer and three-layer composite application napkins were obtained by thermal connection of non-woven needle punch fabrics with carbon fabric. In experimental studies standardized methods for determining of moisture sorption and moisture drying rates were used. It is estimated that daily long-term stay of people with spinal injuries in a wheelchair in a fixed sitting position contributes to the occurrence of ulcers in the places where the bones extend close to the skin surface. It is proposed for people with limited motor ability to use on these places in the apparel garments appliqué linings of therapeutic and prophylactic purpose on the basis of active fibrous carbon sorbents. To provide the necessary prolonged in time sorption-kinetic properties, a number of composite textile materials were produced by the method of thermal connection, in which the medical carbon fabric was combined with needle-punched nonwoven web structures, obtained on the basis of natural plant fibers. The investigation of the influence of raw material composition and structure of nonwoven base on the peculiarities of moisture absorption and drying of such systems have proved the possibility of directed regulation of these processes. The influence of the type of non-woven bases on the peculiarities of regulating the processes of moisture absorption and moisture removal of application composites based on natural plant fibers with carbon fabric is determined. A new range of textile application composite materials with adjustable moisture-transport properties has been developed for use as tabs in medical and preventive garments at places of contact with pressure ulcers.

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Safin, R. R., A. A. Prokopiev, and R. V. Salimgaraeva. "Preacetylation of wood filler in composite materials production." Journal of Physics: Conference Series 2373, no. 2 (December 1, 2022): 022065. http://dx.doi.org/10.1088/1742-6596/2373/2/022065.

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Abstract The increasing swelling pressure of wood filler, occurring during the use of a composite material, leads to the formation of internal microcracks, therefore, reducing the hygroscopicity of the wood filler is an urgent task. This paper considers the wood filler preacetylation technology in wood-polymer composite materials production. Wood particles were acetylated by soaking them in acetic anhydride, followed by heating in a vacuum drying cabinet at 120°C for 40, 180, and 360 minutes. Polylactide in various binder-modified wood filler ratios was used as a polymer matrix in wood-polymer composite samples. The resulting samples were examined for moisture and water absorption. It was found that with a maximum treatment time of 360 minutes moisture and water absorption of samples with 40% wood filler content did not exceed those of a composite with 20% unmodified wood filler content, which proves the effectiveness of acetylation. The results of the research conducted allow expanding the scope of use of additive manufacturing products.

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Zifeng, Yuan, and Fish Jacob. "REDUCED ORDER MULTISCALE ANALYSIS OF MOISTURE DEGRADATION IN COMPOSITE MATERIALS." Chebyshevskii sbornik 18, no. 3 (2017): 280–91. http://dx.doi.org/10.22405/2226-8383-2017-18-3-280-291.

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Neumann, Shoshana, and Gad Marom. "Prediction of Moisture Diffusion Parameters in Composite Materials Under Stress." Journal of Composite Materials 21, no. 1 (January 1987): 68–80. http://dx.doi.org/10.1177/002199838702100105.

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Neumann, Shoshana, and Gad Marom. "Free-volume dependent moisture diffusion under stress in composite materials." Journal of Materials Science 21, no. 1 (January 1986): 26–30. http://dx.doi.org/10.1007/bf01144694.

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Yu, Yunn‐Tzu, and Kishore Pochiraju. "Three‐Dimensional Simulation of Moisture Diffusion in Polymer Composite Materials." Polymer-Plastics Technology and Engineering 42, no. 5 (January 11, 2003): 737–56. http://dx.doi.org/10.1081/ppt-120024993.

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Dvorak, G. J. "Thermal Expansion of Elastic-Plastic Composite Materials." Journal of Applied Mechanics 53, no. 4 (December 1, 1986): 737–43. http://dx.doi.org/10.1115/1.3171852.

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Exact relationships are derived between instantaneous overall thermal stress or strain vectors and instantaneous overall mechanical stiffness or compliance, for two binary composite systems in which one of the phases may deform plastically. Also, the local instantaneous thermal strain and stress concentration factors are related in an exact way to the corresponding mechanical concentration factors. The results depend on instantaneous thermoelastic constants and volume fractions of the phases. They are found for fibrous composites with two distinct elastically isotropic or transversely isotropic phases, and for any binary composite with elastically isotropic phases. The results indicate that in the plastic range the thermal and mechanical loading effects are coupled even if the phase properties do not depend on changes in temperature. The derivation is based on a novel decomposition procedure which shows that spatially uniform elastic strain fields can be created in certain heterogeneous media by superposition of uniform phase eigenstrains with local strains, caused by piecewise uniform stress fields which are in equilibrium with prescribed surface tractions. The method is extended to discretized microstructures, and also to the analysis of moisture absorption and phase transformation effects on overall response and on local fields in the two composite materials.

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Katzman, Howard A., Robert M. Castaneda, and Han Sik Lee. "Moisture diffusion in composite sandwich structures." Composites Part A: Applied Science and Manufacturing 39, no. 5 (May 2008): 887–92. http://dx.doi.org/10.1016/j.compositesa.2008.01.005.

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Patnaik, S. Srikant, and Tarapada Roy. "Viscoelastic and mechanical properties of CNT-reinforced polymer-based hybrid composite materials using hygrothermal creep." Polymers and Polymer Composites 29, no. 9_suppl (November 2021): S1386—S1402. http://dx.doi.org/10.1177/09673911211052730.

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In the present work, a combination of experimental and numerical procedure is proposed to study the effects of different hygrothermal conditions on the creep strain, viscoelastic properties of nanocomposites, and mechanical properties of such nanocomposite-based carbon fiber–reinforced polymer (CFRP) hybrid composite materials. Ultrasonic probe sonicator is used to randomly disperse the multiwalled carbon nanotubes into an epoxy to minimize agglomerations. Dynamic mechanical analysis is employed to conduct the creep tests under different hygrothermal conditions of such nanocomposite samples. The Findley power law is used to obtain the long-term creep behavior of nanocomposite materials. Prony series is used to determine the viscoelastic properties of nanocomposite material in the frequency domain. Coefficient of moisture expansion (CME) is independent of moisture concentration; thus, CME of the nanocomposite is also determined. Strength of materials and Saravanos–Chamis micromechanics (SCM) have also been utilized to obtain the mechanical properties of such hybrid composite materials under different hygrothermal conditions. It has been found that the inclusion of multiwalled carbon nanotubes in the nanocomposite and hybrid composites improves storage modulus and loss factor (i.e., tan δ) compared to the conventional CFRP-based composite materials under hygrothermal conditions.

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Bieniaś, Jarosław, Patryk Jakubczak, Magda Droździel, and Barbara Surowska. "Interlaminar Shear Strength and Failure Analysis of Aluminium-Carbon Laminates with a Glass Fiber Interlayer after Moisture Absorption." Materials 13, no. 13 (July 6, 2020): 2999. http://dx.doi.org/10.3390/ma13132999.

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This article presents selected aspects of an interlaminar shear strength and failure analysis of hybrid fiber metal laminates (FMLs) consisting of alternating layers of a 2024-T3 aluminium alloy and carbon fiber reinforced polymer. Particular attention is paid to the properties of the hybrid FMLs with an additional interlayer of glass composite at the metal-composite interface. The influence of hygrothermal conditioning, the interlaminar shear strength (short beam shear test), and the failure mode were investigated and discussed. It was found that fiber metal laminates can be classified as a material with significantly less adsorption than in the case of conventional composites. Introducing an additional layer of glass composite at the metal-composite interface and hygrothermal conditioning influence the decrease in the interlaminar shear strength. The major forms of damage to the laminates are delaminations in the layer of the carbon composite, at the metal-composite interface, and delaminations between the layers of glass and carbon composites.

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Moudood, Abdul, Anisur Rahman, Andreas Öchsner, Mainul Islam, and Gaston Francucci. "Flax fiber and its composites: An overview of water and moisture absorption impact on their performance." Journal of Reinforced Plastics and Composites 38, no. 7 (December 11, 2018): 323–39. http://dx.doi.org/10.1177/0731684418818893.

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Contemporary researchers have specified that natural flax fiber is comparable with synthetic fibers due to its unique physical and mechanical characteristics which have been recognized for decades. Flax fiber-reinforced composites have the potential for wide usage in sport and maritime industries, and as automotive accessories. In addition, this composite is in the development stages for future applications in the aeronautical industry. However, designing the flax composite parts is a challenging task due to the great variability in fiber properties. This is caused by many factors, including the plant origin and growth conditions, plant age, location in the stem, fibers extraction method, and the fact that there is often a non-uniform cross section of the fibers. Furthermore, the water and moisture absorption tendency of the flax fibers and their composites and the consequent detrimental effects on their mechanical performance are also major drawbacks. Fibers may soften and swell with absorbed water molecules, which could affect the performance of this bio-composite. Flax fibers’ moisture absorption propensity may lead to a deterioration of the fiber–matrix interface, weakening the interfacial strength and ultimately degrading the quality of the composite. This review represents a brief summary of the main findings of research into flax fiber reinforced composites, focusing on the challenges of its water and moisture absorption behavior on their performance.

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Natrayan, L., T. Sathish, S. Baskara Sethupathy, S. Sekar, Pravin P. Patil, G. Velmurugan, and Hunde Hailu. "Interlaminar Shear, Bending, and Water Retention Behavior of Nano-SiO2 Filler-Incorporated Dharbai/Glass Fiber-Based Hybrid Composites under Cryogenic Environment." Adsorption Science & Technology 2022 (July 30, 2022): 1–10. http://dx.doi.org/10.1155/2022/3810884.

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In current history, adding nanoscale and micron-sized filler materials to composite materials for fabrication has been a popular approach for improving the composite’s mechanical characteristics. Due to their lower friction coefficient, excellent mechanical strength modulus, and low moisture uptake, filler-based hybrid composite materials are replacing metallic materials. Glass/Dharbai hybrid composites with nano-SiO2 fillers have been created in this study. After manufacture, the composite materials were treated with liquid nitrogen at 177 K for various durations. Every sample material was cut according to ASTM standards to investigate mechanical features such as ILSS, impact test, and flexural strength. The broken composite specimen was studied using a scanning electron microscope. Water retention studies have been conducted under two distinct liquid solutions: tab or regular water and seawater. ILSS, flexural strength, and water retention were all greater in 4 wt.% of nanofiller-rich composites than in ordinary composites. Compared to 30 minutes, the 15-minute cryo-treated specimens provide the highest mechanical strength. On the other hand, the automobile, aviation, and shipbuilding sectors would benefit from a nanofiller-based composite.

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Obi LE and Uwanugo R-G Uchejiora. "Investigation of moisture absorption rate and diffusivity of plant fibre-reinforced composites." International Journal of Engineering Research Updates 1, no. 2 (December 30, 2021): 029–38. http://dx.doi.org/10.53430/ijeru.2021.1.2.0047.

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This research investigated the moisture absorption rate and diffusivity of plant Fibers-reinforced-composites; using bamboo fiber, raffia and coconut fibers through laboratory experimental investigations. The major limitation of using natural fibers in durable composite applications are their high moisture absorption and poor dimensional stability (swelling); and this swelling of fibers causes micro-cracking and degradation of the composites. In this investigation, the fibers were treated with sodium hydroxide (NaOH) chemical and acetylation to decrease the hydroxyl group in the fibers. Experimental results reveal that the moisture absorption and degree of swelling of the treated bamboo raffia and coconut fiber composites are 25 - 35% lower than those of composites produced with untreated bamboo, raffia and coconut fibers. Experimental results also show that strong intermolecular fiber-matrix bonding decreases the rate of moisture absorption in bio-composites. The diffusivity of the bamboo, raffia and coconut fibers-reinforced-composites for 24hrs at 1000C were experimentally measured to be 4.91, 3.33, and 3.94 mm2/sec respectively. The results showed that when these fiber plant materials are treated with sodium hydroxide (NaON) the diffusivity rate of the fiber reinforced composite material is brought under considerable control and its dimensional stability immensely enhanced though improved strong intermolecular fiber-matrix bonding and the reduction of swelling.

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Trambitski, Yahor, Olga Kizinievič, and Viktor Kizinievič. "Effect of Retrograded Starch Hydrogel on the Hygroscopic and Durability Properties of Clay Composites." Materials 15, no. 24 (December 9, 2022): 8815. http://dx.doi.org/10.3390/ma15248815.

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This study is devoted to assessing the hygroscopic and durability properties of a clay composite with the addition of a natural polymer. Modified polymer-retrograded starch hydrogel (RSH) of various concentrations (2.5, 5.0, 7.5, and 10.0%) and heating times (3 and 5 h) were used as clay stabilizers. The introduction of retrograded starch tends to increase the drying rate of clay composites at the early period of 0–4 days without the formation of shrinkage defects. Moisture uptake increased by 29% (from 140 to 180 g/m2) over the control clay composite without RSH. The hysteresis rate of the clay samples modified with RSH decreased by half (from 0.3 to 0.15%), but the hygroscopic properties were better. The use of RSH polymer increased the durability (water erosion resistance) of the clay composite. The obtained composite has great potential for indoor use due to its high moisture-regulating and durability properties.

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Yang, Yong Jun, In Young Yang, and Ju Ho Choi. "The Collapse Characteristics of CFRP Hat-Shaped Sectional Members under Moisture Absorptions Having the Temperature Change." Key Engineering Materials 535-536 (January 2013): 426–29. http://dx.doi.org/10.4028/www.scientific.net/kem.535-536.426.

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CFRP composite with light weight, high strength, and high elasticity compared to metal is widely used rather than previous steel plates. However, CFRP composite material has the weakness in hygrothermal and impact collapsed environment. Especially, moisture absorption into composite material under hygrothermal environment can change molecule arrangement and chemical properties. Therefore, the purpose of this study lies in acquiring quantitative design data that can be put into the practice by comparing and evaluating the strength degradation under the environment where the moisture is absorbed by conducting static and impact collapse test after setting extreme condition for CFRP composite that takes consistent form such as frontal side members that is actually used in vehicle. This study compared and studied change in the progress of a moisture absorption ratio after setting up the temperature of 60 degrees, and 80 degrees in order to comprehend how the change in the temperature impacts on moisture absorption status inside CFRP composite materials. As a result of this study showed that the strength reduction of about 50% appears due to moisture absorptions. In addition, it showed that the higher the temperature is, the more rapid the progress of a moisture absorption inside CFRP composite materials is. Accordingly, it showed that the change in matrix also has a weak point.

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Gomes dos Santos, Wanessa Raphaella, Rafaela Quinto da Costa Melo, Balbina Raquel de Brito Correia, Hortência Luma Fernandes Magalhães, Endyara de Morais Cabral, Maria José de Figueiredo, and Antonio Gilson Barbosa de Lima. "Water Absorption in Vegetable Fiber-Reinforced Polymer Composites: A Three-Dimensional Investigation Using the Langmuir-Type Model." Defect and Diffusion Forum 399 (February 2020): 164–70. http://dx.doi.org/10.4028/www.scientific.net/ddf.399.164.

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This work presents a non-steady state and three-dimensional mathematical modeling to predict moisture transport (based on the Langmuir-Type Model) inside the vegetable fiber-reinforced composite materials. The numerical solutions of the governing equations have been obtain using the finite-volume method. The model was apply for vegetable fiber-reinforced polymer composites. Emphasis to the geometrical dimension effect of the composite in the water absorption process was given. Results of the average moisture content, free and entrapped water molecules concentration kinetics and free and entrapped water molecules concentration distributions inside the material along the process are shown and analyzed. In the distributions of the analyzed properties, it was observed that the geometric dimensions of the composite has influence in the water absorption process.

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Valluzzi, Maria Rosa, Fabiola Nardon, Enrico Garbin, and Matteo Panizza. "Moisture and Temperature Influence on Biocomposites-to-Timber Bonding." Advanced Materials Research 778 (September 2013): 561–68. http://dx.doi.org/10.4028/www.scientific.net/amr.778.561.

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Compatibility and durability are fundamental aspects to take into account when dealing with strengthening and repair of structural components in existing buildings. In particular, timber elements in floors and roofs, like beams and joists, can be improved in their load-bearing capacity by the use of composite (fiber-reinforced) materials. Applied as textiles or laminates, those materials can provide additional tensile strength without weight increase, and are easily applied in situ. Recently, an increasing interest towards the biocomposites (flax, hemp) opened new perspectives: the advantages in comparison with traditional FRPs includes the higher mechanical compatibility and sustainability, especially if glues suitable for wood (e.g., vinyl) are used as matrix, instead of epoxy resins.In the paper, the results of an experimental campaign carried out at the University of Padua, aimed at investigating the influence of humidity and temperature on the adhesion of composite materials (carbon or glass FRP) and biocomposites (flax) reinforcing spruce timber elements are presented. Epoxy resins were used as matrix for all composites; flax was also applied with vinyl glue and considering a protective treatment (alkaline-based). Effectiveness of bond at the interface timber-reinforcement was measured by pull-off tests, and analyzed at micro-structural level by optical microscopy and infrared spectroscopy.

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Hahn, H. T., and K. S. Kim. "Hygroscopic Effects in Aramid Fiber/Epoxy Composite." Journal of Engineering Materials and Technology 110, no. 2 (April 1, 1988): 153–57. http://dx.doi.org/10.1115/1.3226024.

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Hygroscopic effects in aramid fiber composites are assessed semi-empirically using a combination of micromechanics models and experimental data. It is pointed out that the in situ moisture concentration of the fiber should be known as it affects diffusional as well as expansional properties. The micromechanics models for moisture absorption indicate that the in situ moisture concentration is lower than the bulk value. The interfacial radial stress can be tensile in wet unidirectional composites, and ply cracks are shown to increase moisture diffusion in laminates.

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Badouard, Céline, Chadi Maalouf, Christophe Bliard, Guillaume Polidori, and Fabien Bogard. "Hygric Behavior of Viticulture By-Product Composites for Building Insulation." Materials 15, no. 3 (January 21, 2022): 815. http://dx.doi.org/10.3390/ma15030815.

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One possible approach to reducing the environmental impacts associated with the building sector is the development and use of bio-based building materials. The objective of this study is to determine the water properties of bio-based insulation materials, derived from winegrowing co-products, which promote energy efficiency. The water performance of these new bio-based materials is based on the measurement of the moisture buffer value, the sorption isotherm, and the water vapor permeability. Four by-products are analyzed: stalks, grape pomace, crushed stalks, and skins; they are combined with a potato starch binder. The performance of these composites is compared to two other bio-based composites (hemp/starch and beet pulp/starch). The stalk/starch composite can be classified as a hygroscopic and breathable material with excellent moisture retention capacity.

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Silva, C. J., A. G. Barbosa de Lima, E. Gomes da Silva, T. H. F. de Andrade, and R. Q. da Costa Melo. "Water Absorption in Caroá-Fiber Reinforced Polymer Composite at Different Temperatures: A Theoretical Investigation." Diffusion Foundations 10 (June 2017): 16–27. http://dx.doi.org/10.4028/www.scientific.net/df.10.16.

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Water uptake studies of composite materials reinforced with vegetable fibers shows that they are highly sensitive to environmental influences such as water and temperature. The presence of moisture leads to impregnation and imperfect interfacial fiber-matrix adhesion, which generate internal stresses porosity and premature system failure. Accordingly, the aim of this work is to study theoretically water absorption in unsaturated polyester composites reinforced with caroá fiber (Neoglaziovia Variegata) at 25, 50 and 70°C by using a transient 3D mathematical model via ANSYS CFX® Software. The samples has composition 30% caroá fiber/70% unsaturated polyester resin and dimensions 6 x 20 x 20 mm3. Results of the average moisture content and moisture content distribution during the water uptake are presented and analyzed. Comparison between numerical and experimental data of the average moisture content showed good agreement. It can be concluded that the water absorption rate is faster in the vertex region of the composites, and mainly at higher temperature.

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Lahtela, Ville, and Timo Kärki. "A Study on the Effect of Construction and Demolition Waste (CDW) Plastic Fractions on the Moisture and Resistance to Indentation of Wood-Polymer Composites (WPC)." Journal of Composites Science 5, no. 8 (August 3, 2021): 205. http://dx.doi.org/10.3390/jcs5080205.

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This paper investigated the moisture and strength properties of wood-polymer composites (WPC), which were made using three different recycled polymers using wood flour as filler. The recycled polymers were acrylonitrile butadiene styrene (ABS), polypropylene (PP), and polyethylene (PE), which were collected from among the construction and demolition waste (CDW) at a local waste management center. The commercial additives, such as a coupling agent and lubricant, were also included in the materials. Composite materials were manufactured with an agglomeration and an extrusion process. Water absorption and thickness swelling properties of composites, based on the recycled ABS and PE, were restricted compared to the recycled PP. The strength properties of WPC were determined with two methods, a traditional Brinell hardness and resistance to indentation. Using an ABS polymer as a matrix in the composite, the moisture and strength properties were improved. The recycled PP polymer caused these properties to be lowered, especially in the case of moisture properties. This study has shown that the method used can affect the measured value of certain properties. In addition, the sorting of recycled polymer fractions is desirable for the appearance of improved properties.

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Gueribiz, D., M. Rahmani, F. Jacquemin, S. Fréour, R. Guillen, and K. Loucif. "Homogenization of Moisture Diffusing Behavior of Composite Materials with Impermeable or Permeable Fibers — Application to Porous Composite Materials." Journal of Composite Materials 43, no. 12 (May 27, 2009): 1391–408. http://dx.doi.org/10.1177/0021998308104229.

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Praveen Kumar, A., and M. Nalla Mohamed. "A comparative analysis on tensile strength of dry and moisture absorbed hybrid kenaf/glass polymer composites." Journal of Industrial Textiles 47, no. 8 (July 12, 2017): 2050–73. http://dx.doi.org/10.1177/1528083717720203.

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Economic and environmental concerns lead the researchers toward development of sustainable and renewable materials of which reinforced composites are part of. The abundantly available natural fibers have attracted the researchers to study their performance as reinforcements and feasibility for making automobile components. The performance of composite materials is mainly assessed through their mechanical properties. However, natural fibers to date were mainly used as reinforcements to create bulk composite components with reduced cost rather than improved mechanical performances. Among the methods available for improving mechanical properties of the natural fiber composites, combined mercerization treatment, hybridization, and incorporation of fly ash fillers in the matrix are the best solutions. Therefore, the objective of this research is to evaluate the tensile properties of hybrid kenaf/glass composites with and without fly ash particulate filler as per ASTM standards. Moisture absorption behavior and its effect on the tensile properties of hybrid composites are also investigated. The results revealed that the addition of 10wt % fly ash particles with natural fiber composites increased the tensile strength of composites while hybridization with glass fibers reduced the water absorption properties.

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Souček, J., I. Hanzlíková, and P. Hutla. "A fine desintegration of plants suitable for composite biofuels production." Research in Agricultural Engineering 49, No. 1 (February 8, 2012): 7–11. http://dx.doi.org/10.17221/4945-rae.

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In case of pressed composite biofuels production the important part of the production process is the input row materials disintegration. In dependence on disintegrated material properties, disintegration device, grinding stage and technological process there is in practice necessary for disintegration of culm materials 0.5–7% and of wooden species even 0.75–10% of total energetical content of material. A wide range of these figures means that in this sphere of raw materials adaptation can be reached relative high savings through correct choice of technological process and device. The authors of the paper have measured energy consumption of fine disintegration of lignocellulose materials in dependence on particles size and moisture. By the realized measurement of different average size of both input and output particles and consequent statistical evaluation was proved the fiducial energy consumption increase at higher stage of disintegration and higher moisture of the input material. All measurements were carried-out for the grinding mill &Scaron;K 300 and the output particles size was limited by the exchange sieves mesh dimension.

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Melo, Rafaela Q. C., Marcus V. Lia Fook, and Antonio G. B. de Lima. "Non-Fickian Moisture Transport in Vegetable-Fiber-Reinforced Polymer Composites Using a Langmuir-Type Model." Polymers 12, no. 11 (October 27, 2020): 2503. http://dx.doi.org/10.3390/polym12112503.

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The purpose of this article was to theoretically study the non-Fickian moisture absorption process in vegetable-fiber-reinforced polymer composites using a Langmuir-type model. Here, the focus was on evaluating the effect of the water layer thickness that surrounds the composite during the water migration process. The solutions of the governing equations were obtained using the finite volume method, considering constant thermophysical properties and non-deformable material. The results for the local and average moisture content and concentration, gradient values, and the transient rates of the free and bound (water) molecules in the process were presented and analyzed. It was observed that the water layer thickness strongly influenced the water absorption kinetics, the moisture content gradient values, and the equilibrium moisture content inside the material. It is envisaged that this new approach will contribute to better interpretation of experimental data and a better understanding of the physical phenomenon of water absorption, which directly affects the properties of composite materials.

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Journal articles on the topic 'Composite materials – Moisture'

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