Active Thermal Management of FRP Composites via Embedded Vascular Networks

2019 ◽  
Author(s):  
Jim Cole ◽  
Ian Bond ◽  
Andrew Lawrie
Keyword(s):  
Mechanical Performance ◽  
Flexural Modulus ◽  
Coolant Fluid ◽  
Vascular Networks ◽  
Ambient Conditions ◽  
Test Fixture ◽  
Frp Composites ◽  
Frp Composite ◽  
Thermal Chamber ◽  
The Matrix

Abstract Fibre-reinforced polymer (FRP) composite materials are limited in high temperature applications by the matrix glass transition temperature, Tg. At and above this temperature, significant mechanical performance is lost, and degradation processes accelerated. This research explores the use of internal passages, or vascules, within the laminate to carry a coolant fluid, absorbing heat energy and cooling the material. A custom thermal chamber and four-point flexural test fixture were developed to perform in-situ thermo-mechanical testing. Vascular and non-vascular carbon/epoxy specimens were manufactured, containing arrays of four 1.1 mm diameter vascules. Specimens were exposed to temperatures from ambient to 170 °C (Tg = 200 °C). Flexural modulus varied little with temperature across all tests. Non-vascular specimens at 170 °C showed a reduction in ultimate strength of 21 % compared to under ambient conditions. The presence of vascules caused a small improvement in flexural modulus and strength, due to displacement of a small number of 0° fibre tows further from the neutral axis as a result of the manufacturing process. At 15 L·min−1 coolant flow, vascular specimens showed full retention of strength compared to non-vascular specimens at ambient, demonstrating the potential mechanical performance benefits.

Post-Curing Effects on Marine VARTM FRP Composite Material Properties for Test and Implementation

2005 ◽  
Vol 128 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Jason J. Cain ◽  
Nathan L. Post ◽  
John J. Lesko ◽  
Scott W. Case ◽  
Yin-Nian Lin ◽  
...  
Keyword(s):  
Vinyl Ester ◽  
Mechanical Analysis ◽  
Degree Of Conversion ◽  
Fatigue Performance ◽  
Static Properties ◽  
Degree Of Cure ◽  
Frp Composites ◽  
Frp Composite ◽  
The Matrix ◽  
Term Performance

Structural composites are increasingly being utilized in many large naval and civil structures where it is vital that their long-term performance be predictable and their variability definable over the life of the structure. However, these properties may be influenced by the degree of cure of the resin, particularly for room-temperature-cured systems. Thus, this investigation defines the postcure effects on E-glass/vinyl-ester fiber-reinforced polymer (FRP) composites manufactured using the vacuum-assisted resin transfer molding (VARTM) method, which are typical of those used by the US Navy for ship structures. The composites are differentiated by varying levels of postcure temperature and duration, and examined for the effects of advancing cure at various points in the time after postcure. Pseudo-quasi-isotropic [0/+45/90/−45/0]s and angle ply laminate [±45]2s samples from each level of postcure are examined at 1, 10, 30, 100, and 300 days after postcure in order to track strength, stiffness, failure strain, creep, and fatigue performance as functions of time. In parallel, the matrix polymer is inspected using FTIR (Fourier transform infrared spectroscopy) to directly assess the degree of conversion. Dynamic mechanical analysis and shrinkage measurements are also undertaken to assess the Tg and the amount of shrinkage undergone during post-curing, as well as the advancing of the level of cure during the prescribed aging time. Results suggest that the degree of conversion is limited to 80% for the vinyl-ester oligomer and 90–95% for styrene following a postcure of 93°C. It is observed that after 300 days of ambient storage the nonpostcured samples approach the degree of conversion exhibited by those postcured at 93°C, as measured by FTIR. Resin dominated quasi-static properties are greatly affected by the degree of cure, whereas fiber dominated properties are not. Where the degree of cure is comparatively low, viscoelastic properties cause greater changes in creep response as well as influencing fatigue performance.

scholarly journals Mechanical Properties of Fibre Reinforced Polymers under Elevated Temperatures: An Overview

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2600
Author(s):  
Milad Bazli ◽  
Milad Abolfazli
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Weight Ratio ◽  
High Strength ◽  
Civil Infrastructures ◽  
Frp Composites ◽  
Frp Composite ◽  
Materials Used ◽  
Strength And Stiffness

Fibre-reinforced polymer (FRP) composite is one of the most applicable materials used in civil infrastructures, as it has been proven advantageous in terms of high strength and stiffness to weight ratio and anti-corrosion. The performance of FRP under elevated temperatures has gained significant attention among academia and industry. A comprehensive review on experimental and numerical studies investigating the mechanical performance of FRP composites subjected to elevated temperatures, ranging from ambient to fire condition, is presented in this paper. Over 100 research papers on the mechanical properties of FRP materials including tensile, compressive, flexural and shear strengths and moduli are reviewed. Although they report dispersed data, several interesting conclusions can be drawn from these studies. In general, exposure to elevated temperatures near and above the resin glass transition temperature, Tg, has detrimental effects on the mechanical characteristics of FRP materials. On the other hand, elevated temperatures below Tg can cause low levels of degradation. Discussions are made on degradation mechanisms of different FRP members. This review outlines recommendations for future works. The behaviour of FRP composites under elevated temperatures provides a comprehensive understanding based on the database presented. In addition, a foundation for determining predictive models for FRP materials exposed to elevated temperatures could be laid using the finding that this review presents.

Thermal Ageing Mitigation of FRP Composites Using Vascular Networks

2014 ◽  
Author(s):  
Katarzyna Boba ◽  
Ian Bond ◽  
Richard Trask
Keyword(s):  
Elevated Temperatures ◽  
Thermal Ageing ◽  
Vascular Networks ◽  
Significant Drop ◽  
Frp Composites ◽  
Fibre Bridging ◽  
Beam Shear ◽  
The Matrix ◽  
Isothermal Ageing

Incorporation of multifunctionality to fibre reinforced polymer composite materials delivers many benefits. One example includes improved longevity of components through increasing permissible temperatures of operation, which could be achieved via in-situ cooling. As the temperature of composite components approaches the glass transition temperature (Tg) of the matrix, thermal stress induced ageing greatly increases [1], [2], thus the incentive for integrated cooling. In order to assess the damage, which could be caused by exposure to elevated temperatures, isothermal ageing was performed at a temperature 15°C lower than the materials Tg (2200 hours at 110°C). Material used in this study is a carbon/epoxy prepreg system (Gurit, SE70), with a Tg of 126°C when cured at 110°C. Results have shown a significant drop in Short Beam Shear (SBS) Strength starting after exposure for 1700h and increase in fibre bridging seen in mode I Double Cantilever Beam (DCB) testing. Fracture surface analysis using SEM indicated that fibres were generally less well bonded to the matrix, with visible changes began occurring as early as 1000h exposure. These results indicate that extended exposure of a material at near Tg temperatures has a detrimental effect on material properties. To mitigate against this phenomenon, a series of tests were performed on SBS and DCB specimens in a raised temperature (110°C) environment, which incorporated in-situ cooling. The specimens were placed in an oven at 110°C and were cooled down to a constant temperature of 60°C via the internal vascular cooling arrangement. Further testing is underway to assess the inhibition of ageing and maintenance of the original composite material by active cooling using embedded vascular networks.

Impact Strength, Flexural Modulus and Wear Rate of PMMA Composites Reinforced by Eggshell Powders

2020 ◽  
Vol 38 (7A) ◽  
pp. 960-966
Author(s):  
Aseel M. Abdullah ◽  
Hussein Jaber ◽  
Hanaa A. Al-Kaisy
Keyword(s):  
Impact Strength ◽  
Wear Rate ◽  
Flexural Modulus ◽  
Matrix Material ◽  
Weight Fraction ◽  
Pure Pmma ◽  
Calcination Process ◽  
The Matrix ◽  
The Impact ◽  
Interface Bond

In the present study, the impact strength, flexural modulus, and wear rate of poly methyl methacrylate (PMMA) with eggshell powder (ESP) composites have been investigated. The PMMA used as a matrix material reinforced with ESP at two different states (including untreated eggshell powder (UTESP) and treated eggshell powder (TESP)). Both UTESP and TESP were mixed with PMMA at different weight fractions ranged from (1-5) wt.%. The results revealed that the mechanical properties of the PMMA/ESP composites were enhanced steadily with increasing eggshell contents. The samples with 5 wt.% of UTESP and TESP additions give the maximum values of impact strength, about twice the value of the pure PMMA sample. The calcination process of eggshells powders gives better properties of the PMMA samples compared with the UTESP at the same weight fraction due to improvements in the interface bond between the matrix and particles. The wear characteristics of the PMMA composites decrease by about 57% with increases the weight fraction of TESP up to 5 wt.%. The flexural modulus values are slightly enhanced by increasing of the ESP contents in the PMMA composites.

scholarly journals Preparation of Long Sisal Fiber-Reinforced Polylactic Acid Biocomposites with Highly Improved Mechanical Performance

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1124
Author(s):  
Zhifang Liang ◽  
Hongwu Wu ◽  
Ruipu Liu ◽  
Caiquan Wu
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Mechanical Performance ◽  
Tensile Elongation ◽  
Sisal Fiber ◽  
Fiber Reinforced ◽  
Impact Performance ◽  
The Matrix ◽  
Blending Process ◽  
Extension Direction

Green biodegradable plastics have come into focus as an alternative to restricted plastic products. In this paper, continuous long sisal fiber (SF)/polylactic acid (PLA) premixes were prepared by an extrusion-rolling blending process, and then unidirectional continuous long sisal fiber-reinforced PLA composites (LSFCs) were prepared by compression molding to explore the effect of long fiber on the mechanical properties of sisal fiber-reinforced composites. As a comparison, random short sisal fiber-reinforced PLA composites (SSFCs) were prepared by open milling and molding. The experimental results show that continuous long sisal fiber/PLA premixes could be successfully obtained from this pre-blending process. It was found that the presence of long sisal fibers could greatly improve the tensile strength of LSFC material along the fiber extension direction and slightly increase its tensile elongation. Continuous long fibers in LSFCs could greatly participate in supporting the load applied to the composite material. However, when comparing the mechanical properties of the two composite materials, the poor compatibility between the fiber and the matrix made fiber’s reinforcement effect not well reflected in SSFCs. Similarly, the flexural performance and impact performance of LSFCs had been improved considerably versus SSFCs.

scholarly journals Rapid synchronized fabrication of vascularized thermosets and composites

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mayank Garg ◽  
Jia En Aw ◽  
Xiang Zhang ◽  
Polette J. Centellas ◽  
Leon M. Dean ◽  
...  
Keyword(s):  
Large Scale ◽  
Capillary Flow ◽  
External Heat ◽  
Frontal Polymerization ◽  
Self Healing ◽  
Vascular Networks ◽  
Ambient Conditions ◽  
External Energy ◽  
Imaging Phantoms ◽  
Vascular Structures

AbstractBioinspired vascular networks transport heat and mass in hydrogels, microfluidic devices, self-healing and self-cooling structures, filters, and flow batteries. Lengthy, multistep fabrication processes involving solvents, external heat, and vacuum hinder large-scale application of vascular networks in structural materials. Here, we report the rapid (seconds to minutes), scalable, and synchronized fabrication of vascular thermosets and fiber-reinforced composites under ambient conditions. The exothermic frontal polymerization (FP) of a liquid or gelled resin facilitates coordinated depolymerization of an embedded sacrificial template to create host structures with high-fidelity interconnected microchannels. The chemical energy released during matrix polymerization eliminates the need for a sustained external heat source and greatly reduces external energy consumption for processing. Programming the rate of depolymerization of the sacrificial thermoplastic to match the kinetics of FP has the potential to significantly expedite the fabrication of vascular structures with extended lifetimes, microreactors, and imaging phantoms for understanding capillary flow in biological systems.

scholarly journals Long-fibre reinforced polymer composites by 3D printing: influence of nature of reinforcement and processing parameters on mechanical performance

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Francis Dantas ◽  
Kevin Couling ◽  
Gregory J. Gibbons
Keyword(s):  
Carbon Fibre ◽  
Polymer Composites ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Matrix Material ◽  
Processing Parameters ◽  
Fibre Reinforcement ◽  
Reinforced Polymer ◽  
Unreinforced Material ◽  
Fibre Reinforced Polymer

Abstract The aim of this study was to identify the effect of material type (matrix and reinforcement) and process parameters, on the mechanical properties of 3D Printed long-fibre reinforced polymer composites manufactured using a commercial 3D Printer (Mark Two). The effect of matrix material (Onyx or polyamide), reinforcement type (Carbon, Kevlar®, and HSHT glass), volume of reinforcement, and reinforcement lay-up orientation on both Ultimate Tensile Strength (UTS) and Flexural Modulus were investigated. For Onyx, carbon fibre reinforcement offered the largest increase in both UTS and Flexural Modulus over unreinforced material (1228 ± 19% and 1114 ± 6% respectively). Kevlar® and HSHT also provided improvements but these were less significant. Similarly, for Nylon, the UTS and Flexural Modulus were increased by 1431 ± 56% and 1924 ± 5% by the addition of carbon fibre reinforcement. Statistical analysis indicated that changing the number of layers of reinforcement had the largest impact on both UTS and Flexural Strength, and all parameters were statistically significant.

scholarly journals Nanocomposites Materials of PLA Reinforced with Nanoclays Using a Masterbatch Technology: A Study of the Mechanical Performance and Its Sustainability

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2133
Author(s):  
Helena Oliver-Ortega ◽  
Josep Tresserras ◽  
Fernando Julian ◽  
Manel Alcalà ◽  
Alba Bala ◽  
...  
Keyword(s):  
Food Packaging ◽  
Mechanical Performance ◽  
Polymeric Materials ◽  
Barrier Properties ◽  
Food Tray ◽  
Environmental Concerns ◽  
Poly Lactic Acid ◽  
The Matrix ◽  
Surface Modified ◽  
Being Moved

Packaging consumes around 40% of the total plastic production. One of the most important fields with high requirements is food packaging. Food packaging products have been commonly produced with petrol polymers, but due to environmental concerns, the market is being moved to biopolymers. Poly (lactic acid) (PLA) is the most promising biopolymer, as it is bio-based and biodegradable, and it is well established in the market. Nonetheless, its barrier properties need to be enhanced to be competitive with other polymers such as polyethylene terephthalate (PET). Nanoclays improve the barrier properties of polymeric materials if correct dispersion and exfoliation are obtained. Thus, it marks a milestone to obtain an appropriate dispersion. A predispersed methodology is proposed as a compounding process to improve the dispersion of these composites instead of common melt procedures. Afterwards, the effect of the polarity of the matrix was analyzing using polar and surface modified nanoclays with contents ranging from 2 to 8% w/w. The results showed the suitability of the predispersed and concentrated compound, technically named masterbatch, to obtain intercalated structures and the higher dispersion of polar nanoclays. Finally, the mechanical performance and sustainability of the prepared materials were simulated in a food tray, showing the best assessment of these materials and their lower fingerprint.

scholarly journals Assessing the Flexural Properties of Epoxy Composites with Extremely Low Addition of Cellulose Nanofiber Content

2020 ◽  
Vol 10 (3) ◽  
pp. 1159 ◽  
Author(s):  
Yingmei Xie ◽  
Hiroki Kurita ◽  
Ryugo Ishigami ◽  
Fumio Narita
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Flexural Modulus ◽  
Strengthening Mechanism ◽  
Short Fiber ◽  
Cellulose Nanofiber ◽  
Resin Matrix ◽  
Element Analysis ◽  
Epoxy Resin Matrix ◽  
The Matrix

Epoxy resins are a widely used common polymer due to their excellent mechanical properties. On the other hand, cellulose nanofiber (CNF) is one of the new generation of fibers, and recent test results show that CNF reinforced polymers have high mechanical properties. It has also been reported that an extremely low CNF addition increases the mechanical properties of the matrix resin. In this study, we prepared extremely-low CNF (~1 wt.%) reinforced epoxy resin matrix (epoxy-CNF) composites, and tried to understand the strengthening mechanism of the epoxy-CNF composite through the three-point flexural test, finite element analysis (FEA), and discussion based on organic chemistry. The flexural modulus and strength were significantly increased by the extremely low CNF addition (less than 0.2 wt.%), although the theories for short-fiber-reinforced composites cannot explain the strengthening mechanism of the epoxy-CNF composite. Hence, we propose the possibility that CNF behaves as an auxiliary agent to enhance the structure of the epoxy molecule, and not as a reinforcing fiber in the epoxy resin matrix.

The all-composite road bridge – a proposal for rapid urbanisation

2018 ◽  
Author(s):  
Tomasz Siwowski ◽  
Aleksander Kozlowski ◽  
Leonard Ziemiański ◽  
Mateusz Rajchel ◽  
Damian Kaleta
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Construction Materials ◽  
Fast Growing ◽  
Frp Composites ◽  
Frp Composite ◽  
Reinforced Polymer ◽  
Composite Bridge ◽  
Fibre Reinforced Polymer ◽  
Traditional Construction

<p>Technology and materials can help cities get smarter and cope with rapid urbanisation. Life cycle assessment (LCA) is one of the approaches applied in evaluation of material sustainability. Many significant LCA comparisons of innovative and traditional construction materials indicate that fibre- reinforced polymer (FRP) composites compare very favourably with other materials studied. As a proposal for rapid urbanisation, the FRP all-composite road bridge was developed and demonstrated in Poland. The paper describes the bridge system itself and presents the results of research on its development. The output of the R&amp;D project gives a very promising future for the FRP composite bridge application in Poland, especially for cleaner, resilient and more environmentally efficient infrastructure of fast-growing cities.</p>

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