Measurement of Epoxy Stiffness by Atomic Force Acoustic Microscopy

2009 ◽  
Author(s):  
Wei Zhao ◽  
Chad S. Korach
Keyword(s):  
Polymer Composites ◽  
Environmental Conditions ◽  
Mechanical Characteristics ◽  
Acoustic Microscopy ◽  
Epoxy Composites ◽  
Atomic Force ◽  
Reinforced Polymer ◽  
And Performance ◽  
Composite Response

The mechanical characteristics of the epoxy matrix found in filler reinforced polymer composites is important for determining strength and performance. Locally, property variations in regions surrounding fillers can influence the overall macroscopic composite response to loading. We investigate local nanomechanical stiffness of reinforced epoxy composites by using atomic force acoustic microscopy. The effects of tip shape on the contact mechanics at the epoxy interface are found to influence the reported results significantly and will be discussed in context of different tip models. The results have direct correlation to the effect of near-filler interphase regions and the long-term influence of environmental conditions on the polymer composites.

Tensile Properties of Epoxy Matrix Reinforced with Fique Fabric

2020 ◽  
Vol 1012 ◽  
pp. 14-19
Author(s):  
Michelle Souza Oliveira ◽  
Fabio da Costa Garcia Filho ◽  
Fernanda Santos da Luz ◽  
Artur Camposo Pereira ◽  
Luana Cristyne da Cruz Demosthenes ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Polymer Composites ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Polymer ◽  
Epoxy Composites ◽  
Synthetic Fiber ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites

Composite materials are being extensively studied for ballistic armor. Their main advantage is connected to the possibility of deeply reducing weight and costs by maintaining high performances in terms of strength and security. Epoxy composites are reinforced with natural fibers which are replacing other synthetic reinforcement materials. Composites are prepared using polymers as matrix material because of ease of production with different reinforcements. The mechanical strength of the natural fiber reinforced polymer composites has been compared with synthetic fiber reinforced polymer composites and it is found that for achieving equivalent mechanical strength of the material, the volume fraction of the natural fiber should be much higher than synthetic fiber. This work being an experimental study on untreated “as received” fique fabric-reinforced epoxy composites, to demonstrate the potential of this renewable source of natural fiber for use in a number of applications.

Nanoscale Structural and Mechanical Characterization of Nanowire-Reinforced Polymer Composites

2011 ◽  
Author(s):  
Wyatt Leininger ◽  
Xinnan Wang ◽  
X. W. Tangpong ◽  
Marshall McNea
Keyword(s):  
Elastic Modulus ◽  
Tensile Testing ◽  
Mechanical Characterization ◽  
Tensile Load ◽  
Small Strain ◽  
Epoxy Composites ◽  
Atomic Force ◽  
Reinforced Polymer ◽  
Multi Walled Carbon Nanotube

In this study, the mechanical properties of multi-walled carbon nanotube (MWCNT) reinforced epoxy composites were characterized using an in-house designed micro/nano tensile load stage in conjunction with an atomic force microscope (AFM). The surface of the nanocomposite was scanned by the AFM during intermittent tensile testing. Micro/nano deformation was observed, and the reinforcing mechanisms were discussed in conjunction with architecture and elastic modulus. Results show that the MWCNT reinforced nanocomposite has an increased elastic modulus. The Halpin-Tsai and Hui-Shia models were compared to the experimental results, and the Halpin-Tsai was found to correlate when only the load bearing outer layer of the MWCNTs were considered. Additionally, it is concluded that the combination of the load stage and AFM is capable of capturing insitu deformation progress for small strain increments.

Study on Mechanical Characteristics of Nanoclay Reinforced Polymer Composites

2017 ◽  
Vol 4 (10) ◽  
pp. 11158-11162 ◽  
Author(s):  
Manjunath Shettar ◽  
U Achutha Kini ◽  
SS Sharma ◽  
Pavan Hiremath
Keyword(s):  
Polymer Composites ◽  
Mechanical Characteristics ◽  
Reinforced Polymer

scholarly journals Electro-thermal and mechanical performance of multi-wall carbon nanotubes buckypapers embedded in fibre reinforced polymer composites for ice protection applications

2020 ◽  
Vol 54 (23) ◽  
pp. 3457-3469 ◽  
Author(s):  
Francesco Zangrossi ◽  
Fang Xu ◽  
Nick Warrior ◽  
Petros Karapappas ◽  
Xianghui Hou
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Polymer Composites ◽  
Mechanical Characteristics ◽  
Thermal Method ◽  
Multi Wall Carbon Nanotubes ◽  
Self Heating ◽  
Resin Impregnation ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

Several ice protection strategies have been developed to overcome the icing hazards in the aerospace industry. The electro-thermal method is one of the popular approaches to prevent ice accretion and accumulation on aircraft surfaces. Given the increasing requirement of composites on aircraft structures, metal frameworks/fibre-reinforced composites have been developed as a de-icing solution for the new generation aircraft. The present work aimed to fabricate self-heating multi-wall carbon nanotubes based composites for ice protection and to study their electro-thermal and mechanical characteristics. Carbon nanotube buckypapers (CNPs) were prepared and embedded in fibre reinforced polymer composites by two methods: pre-preg and resin impregnation. The influence of the carbon nanotube network structure on the mechanical properties and electrical characteristics of the composites was evaluated. Mechanical tests, three-point flexural test and interlaminar shear strength test demonstrated improved mechanical characteristics of the CNP based composites. De-icing performance of the composites was conducted through a heating test in a climate chamber at −20℃. The results indicated that the CNP-based composite is a promising self-heating material candidate for ice protection systems.

scholarly journals Moisture Absorption Studies of COIR and Sisal Short Fiber Reinforced Polymer Composites

2021 ◽  
Vol 9 (9) ◽  
pp. 116-127
Author(s):  
Ambareesh K V
Keyword(s):  
Water Absorption ◽  
Polymer Composites ◽  
Moisture Absorption ◽  
Natural Fiber ◽  
Sea Water ◽  
Natural Fibre ◽  
Epoxy Composites ◽  
Fiber Reinforced ◽  
Short Fibers ◽  
Reinforced Polymer

Abstract: Easy availability of natural fibre, low cost and ease of manufacturing have urged the attention of researchers towards the possibility of reinforcement of natural fiber to improve their mechanical properties and study the extent to which they satisfy the required specifications of good reinforced polymer composite for industrial and structural applications. Polymer composites made of natural fiber is susceptible for moisture. Moisture absorption in such composites mainly because of hydrophilic nature of natural fibers. Water uptake of natural fiber reinforced composites has an effect on different. Lot of researchers prepared the natural fiber reinforced composites without conducting water absorption tests; hence it is the potential area to investigate the behavior of the composites with different moisture absorption. In this research the experimental sequence and the materials are used for the study of coir and Sisal short fiber reinforced epoxy matrix composites. The coir and Sisal short fibers are made into the short fibers with 10 mm x 10 mm x 5 mm size. The Epoxy Resin-LY556(Di glycidyl ether of bi phenol) and Hardner-HYD951 (Tetra mine), the water absorption behaviors are analyzed in the coir and Sisal short fibers reinforced epoxy composites. The water absorption behaviors of the epoxy composites reinforced with the coir and sisal short fibers with 25, 30 and 35wt% were analyzed at three different water environments, such as sea water, distilled water, and tap water for 12 days at room temperature. It was observed that the composites show the high level of the water absorption percentage at sea water immersion as compared to the other water environments. Due to the water absorption, the mechanical properties of macro particle/epoxy composites were decreased at all weight percentages. Keywords: Natural fibre, Moisture absorption, Coir and sisal short fibre, Reinforced polymer composites, Water absorption behaviour Polymer matrix composite (Epoxy resin) using Coir and sisal short fibre and to study its moisture absorption behaviour

scholarly journals Temperature-Frequency–Dependent Viscoelastic Properties of Neat Epoxy and Fiber Reinforced Polymer Composites: Experimental Characterization and Theoretical Predictions

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1700 ◽  
Author(s):  
Kakur Naresh ◽  
Kamran Ahmed Khan ◽  
Rehan Umer ◽  
Alagumalai Vasudevan
Keyword(s):  
Epoxy Resin ◽  
Polymer Composites ◽  
Fiber Reinforced Polymer ◽  
Epoxy Composites ◽  
Neat Epoxy ◽  
Frequency Dependent ◽  
Viscoelastic Models ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Storage And Loss Moduli

In general, aerospace structures manufactured using fiber reinforced polymer composites are exposed to fluctuating temperatures and subjected to cyclic loading during their service life. Therefore, studying the temperature-frequency dependent properties of composites for different fiber orientations is essential. However, such experiments are expensive, time-consuming and labor-intensive while theoretical models minimize these issues, but temperature-frequency-dependent viscoelastic models for predicting the full-range of the storage and loss moduli curves of composites are limited. In this study, the dynamic mechanical properties of a neat epoxy resin, unidirectional ([0°]6, [45°]6 and [90°]6), symmetric angle-ply [+45°/−45°/+45°]s and quasi-isotropic [±45°/0°/90°]s carbon/epoxy and glass/epoxy composite panels were investigated. Experiments were performed from room temperature (approximately 35 °C) to 160 °C at five different frequencies (1, 10, 20, 33 and 50 Hz). Two parameter viscoelastic models as function of temperature and frequency were used, and their applicability in predicting the storage and loss moduli for the entire region of the temperature curve is shown. The storage modulus values were compared and validated against the static flexural modulus values coupled with scanning electron microscopy analysis. The flexural and storage moduli values were found to be higher for [0°]6 carbon/epoxy composites, while the activation energy values were found to be higher in the case of [+45°/−45°/+45°]s carbon/epoxy composites compared with epoxy resin and other laminates in different orientations. The predicted results were in reasonably good agreement with the experiments. Both experimental and modeling approaches used in this study are highly valuable for designing aerospace composites for harsh in-service loading conditions.

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