scholarly journals Microwave Assisted Healing of Thermally Mendable Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Edward D. Sosa ◽  
Thomas K. Darlington ◽  
Brian A. Hanos ◽  
Mary Jane E. O’Rourke
Keyword(s):  
Polymer Matrix ◽  
Composite Structures ◽  
Damage Tolerance ◽  
Polymer Matrix Composites ◽  
Control Sample ◽  
Healing Time ◽  
Self Healing ◽  
Microwave Source ◽  
Microwave Exposure ◽  
Specific Strength

Polymer matrix composites offer high specific strength; however, their potential weight savings have been limited by the concern of damage tolerance. If microcracking and similar incurred damage could be autonomously sealed, composite structures could be built thinner and lighter while still addressing damage tolerance, thus achieving the weight savings they promise. Various self-healing mechanisms have been proposed to this end. Herein, a method of thermally reversible polymerization is investigated. To date, thermally activated repair of composites have been accomplished typically through resistive heating, which has certain inherent complexities. An alternate heating method, via microwave exposure of carbon nanotubes incorporated throughout a thermal reversible polymer matrix, is demonstrated. Carbon nanotube-doped composites exhibit enhanced microwave absorption over an undoped control sample. Furthermore, it is shown that these composites can be heated locally by a focused microwave source. The particular composite formulation and layup studied could be uniformly heated to the targeted healing temperature of 100°C in as little as 20 seconds, followed by a healing time on the scale of minutes with total time depending upon the extent of damage.

A probabilistic approach for design and certification of self-healing advanced composite structures

2011 ◽  
Vol 225 (4) ◽  
pp. 435-449 ◽  
Author(s):  
H R Williams ◽  
R S Trask ◽  
I P Bond
Keyword(s):  
Composite Structures ◽  
High Performance ◽  
Probabilistic Approach ◽  
Healing Time ◽  
Self Healing ◽  
Structural Failure ◽  
Healing System ◽  
Order Of Magnitude ◽  
Damage Tolerant

Design and certification of novel self-healing aerospace structures was explored by reviewing the suitability of conventional deterministic certification approaches. A sandwich structure with a vascular network self-healing system was used as a case study. A novel probabilistic approach using a Monte Carlo method to generate an overall probability of structural failure yields notable new insights into design of self-healing systems, including a drive for a faster healing time of less than two flight hours. In the case study considered, a mature self-healing system could be expected to reduce the probability of structural failure (compared to a conventional damage-tolerant construction) by almost an order of magnitude. In a risk-based framework this could be traded against simplified maintenance activity (to save cost) and/or increased allowable stress (to allow a lighter structure). The first estimate of the increase in design allowable stresses permitted by a self-healing system is around 8 per cent, with a self-healing system much lighter than previously envisaged. It is thought these methods and conclusions could have wider application to self-healing and conventional high-performance composite structures.

An Information System for Damage Tolerance of Polymer Matrix Composites

1999 ◽  
Vol 121 (4) ◽  
pp. 524-529
Author(s):  
Ozgur Turkgenc ◽  
Reza Dianati ◽  
Milan Mitrovic ◽  
H. Thomas Hahn ◽  
Peter Shyprykevich
Keyword(s):  
Information System ◽  
Polymer Matrix ◽  
Damage Tolerance ◽  
Polymer Matrix Composites ◽  
Data Retrieval ◽  
Generic Model ◽  
Matrix Composites ◽  
Case Examples ◽  
Damage Area ◽  
Reference Information

Much research has been conducted to understand the damage tolerance behavior of polymer matrix composites, but there are so many parameters involved that the development of a generic model is rather difficult. The present paper proposes an information system, which can overcome such difficulty. In this system, a list of possible parameters is generated and used as input. The output contains compression strength after impact, dent depth and damage area as well as pertinent reference information. The information system is constituted in a relational database environment and tools from expert system technology are incorporated. Case examples are included to demonstrate the practical use of the software for both data retrieval and similarity studies.

Wear Resistant Polymer Matrix Composites for Aerospace Applications

2004 ◽  
Author(s):  
Subhash K. Naik ◽  
James K. Sutter ◽  
Widen Tabakoff ◽  
Robert G. Siefker ◽  
Harold S. Haller ◽  
...  
Keyword(s):  
Polymer Matrix ◽  
Polymer Matrix Composites ◽  
Matrix Composites ◽  
Maintenance Costs ◽  
Specific Strength ◽  
Aerospace Applications ◽  
High Specific Strength ◽  
Test Conditions ◽  
Sand Erosion ◽  
Engine Components

Polymer matrix composites (PMCs) are attractive for use in propulsion engine components due to their high specific strength. The use of composites could be even more advantageous if the sand erosion life of the component were extended, thereby reducing maintenance costs. NASA Glenn Research Center (NASA GRC) and Rolls-Royce Corporation have developed erosion resistant coatings that can extend PMC component life and are applicable to current available and advanced high temperature PMCs. This paper describes the performance of SANPRES and SANRES, two similar erosion resistant coating systems that were subjected to engine test conditions on Rolls-Royce AE 3007 engine bypass vanes.

Computational Analysis of Self-Healing in a Polymer Matrix With Microvascular Networks

2008 ◽  
Author(s):  
Jose Martinez Lucci ◽  
R. S. Amano ◽  
Pradeep Rohatgi
Keyword(s):  
Polymer Matrix ◽  
Mechanical Performance ◽  
Polymer Matrix Composites ◽  
Self Healing ◽  
Matrix Composites ◽  
Microvascular Networks ◽  
Microvascular Network ◽  
Matrix Surface ◽  
The Matrix ◽  
Healing Agent

For the last decade, many researchers have been working to develop self-healing materials, and have obtained good results in the field of polymers, these components with microencapsulated healing agent have exhibited noticeable mechanical performance and regenerative property The research described in this paper applies the concept of self healing to simulate self healing polymer matrix composites, with the aid of models developed by the authors for the manufacturing processes and self-healing behavior. The development of self-healing is a novel idea that has not been totally explored in great detail yet. The concept of self-healing described in this paper consists of simulation of a healing agent dicyclopentadiene (DCPD) inside of a microvascular network within a polymer matrix coating with catalyst forming a self-healing composite (SHC). When this SHC is damaged or cracked, the healing agent by capillary action will flow inside of the microvascular network; when the liquid enter in contact with the catalyst will form a polymer structure and sealing the crack. The study consists of theoretical analysis and Computational Fluid Dynamics of a self-healing polymer. The objective of the study reported here was to find the influence and efficiency of the microvascular network in healing a polymer matrix. To check this effect a computational model was created to simulate the healing treatment, thus a crack was created on the matrix surface piercing the microvascular network filled with healing agent and the method to simulate healing behavior of the composite allows assessment of the effects of the autonomously repairing repeated damage events.

scholarly journals Comparative Study of the Mechanical and Water Absorption Behaviour of Basalt Fiber Reinforced Polymer Matrix Composites with Different Epoxies as Matrix for Biomedical Applications

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
R. Raghavendra Rao ◽  
S. Pradeep ◽  
Nasim Hasan ◽  
B. S. Shivashankara ◽  
Mohamed Abdelghany Elkotb ◽  
...  
Keyword(s):  
Water Absorption ◽  
Polymer Matrix ◽  
Biomedical Applications ◽  
Polymer Matrix Composites ◽  
Testing Machine ◽  
Basalt Fiber ◽  
Weight Ratio ◽  
Matrix Composites ◽  
Specific Strength ◽  
The Many

In comparison to conventional materials, polymer matrix composite materials have witnessed a surge in applicability due to their higher specific strength-to-weight ratio, abundant availability, and ease of shaping. Due to technological, economic, environmental, and societal challenges, bio-based fibers began to emerge quickly for use in industrial components. Due to its unique chemistry-related characteristics, basalt fiber holds a prominent position among the many bio-based fibers. So, it could be thought of used as a replacement for some components used in the biomedical equipments. In the present investigation, plain-woven basalt fiber at a constant percentage of 55% is added as reinforcement to three different epoxy resin-hardener combinations such as Lapox L12-Lapox K6, Araldite LY1564-Aradur 22962, and Araldite LY556-Aradur HY951 as matrix, and comparative studies are carried out. Fabrication is carried out by hand lay-up technique. Test specimens are prepared as per the respective ASTM standards by subjecting the laminate to water jet machining. Mechanical characterization such as tensile, flexural, and density tests is conducted for the test specimen using BISS-50 kN Universal Testing Machine (UTM). Water absorption tests are also conducted for 24 and 48 hours duration. From the results obtained, it is concluded that the highest tensile, flexural strengths are obtained for laminate L3 which used LY556 epoxy and HY951 hardener combination as matrix. Also, less rate of water absorption is seen for L3 laminate for both 24 and 48 hrs which makes it suitable for biomedical applications.

scholarly journals Computational Modeling of Polymer Matrix Composites

2018 ◽  
Author(s):  
DC Pham
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Composite Materials ◽  
Polymer Matrix ◽  
Composite Structures ◽  
Computational Models ◽  
Polymer Matrix Composites ◽  
Failure Criteria ◽  
Matrix Composites ◽  
Stiffness Reduction

Applications of polymer matrix composites are growing in aerospace and offshore industries due to the light-weight and good mechanical properties of composite materials. The design of composite materials can be made at macroscopic level in which the composite mechanical properties can be tailored to offer the most desired performance of composite structures. Understanding on mechanical behavior of the composite material may require detailed investigations at the microscopic level involving the behaviour of the composite constituents such as the fiber, the polymer matrix and the fiber/matrix interface under macroscopic loads. Composite failure criteria are often employed to evaluate the failure of composite material and its constituents. Computational damage models can be then developed to reflect the stiffness reduction of the material once damage at the macro- and micro- scales of the composite is indicated. The successful prediction of composite structures relies on consistent computational models which can capture the mechanical behaviour of composite materials at different length scales.

scholarly journals Multifunctional Thermally Remendable Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Edward D. Sosa ◽  
Thomas K. Darlington ◽  
Brian A. Hanos ◽  
Mary Jane E. O’Rourke
Keyword(s):  
Carbon Nanotubes ◽  
Damage Tolerance ◽  
Polymer Matrix Composites ◽  
Mechanical And Thermal Properties ◽  
Self Healing ◽  
Matrix Composites ◽  
Damage Site ◽  
Heating Efficiency ◽  
Thermally Activated ◽  
Polymer Resin

Challenges associated with damage tolerance in polymer matrix composites must be successfully addressed in order to ensure highly reliable structures with significant weight savings. Self-healing materials provide a viable means to surmount damage tolerance concerns, thereby allowing for the realization of the mass reduction such structures have promised but not yet achieved. Introduction of multifunctional properties into self-healing composites can further extend their usefulness. This study examines the incorporation of carbon nanotubes into a self-healing composite in order to achieve this. Composite panels were fabricated with carbon fibers, a bismaleimide tetrafuran (2MEP4F) polymer resin, and various carbon nanotube materials. The composites exhibit enhancement in electrical, mechanical, and thermal properties. The healing mechanism is a thermally activated reversible polymerization of the 2MEP4F resin. The proposed method of heating exploits the enhanced microwave absorption inherent to carbon nanotubes to provide the thermal energy required for the reversible polymerization. Microwave testing demonstrated that the heating efficiency is increased, allowing uniform heating to the required temperature for polymer healing. Impacted composites show localized heating at the damage site, which implies that microwave heating can also be used as a means for damage detection and potential structural health monitoring.

On the Transient Hygroscopic Stresses in Polymer Matrix Laminated Composites Plates with Cyclic and Unsymmetric Environmental Conditions

2005 ◽  
Vol 13 (5) ◽  
pp. 489-503 ◽  
Author(s):  
A. Tounsi ◽  
M. Bouazza ◽  
S. Meftah ◽  
E. Adda-Bedia
Keyword(s):  
Polymer Matrix ◽  
Composite Structures ◽  
Polymer Matrix Composites ◽  
Matrix Composites ◽  
Stress Distributions ◽  
Moist Environment ◽  
Cyclic Variations ◽  
Transient Hygroscopic Stresses ◽  
Structural Parts

The use of aircraft structural parts made of polymer matrix composites subjected to severe environment conditions calls for better knowledge of their long – term behaviour, with an emphasis on their ability to withstand important cyclic variations of moisture and temperature. The influence of temperature and moisture on such structures is receiving special attention, because it induces transient residual stresses within the plies. Such stresses must be taken into account in the design of composite materials, particularly aerospace structures, e.g. aircraft. In the present paper the transient hygroscopic stresses induced by cyclic and unsymmetric environmental loadings which simulate an aeronautical application are investigated. It is shown that the heterogeneity and anisotropy of such plates generally result in transient stress distributions which are very different from the equilibrium stress distribution. Some stacking sequences exhibit important stresses within the plies. These stresses have to be taken into account in the design of composite structures submitted to a moist environment.

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