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2017-10-13
Technical Paper
2017-01-5012
Harveer Singh Pali, Shashi Prakash Dwivedi
Abstract The present work deals with the fabrication and tribological testing of an aluminium/SiC composite. Fabrication was done using two techniques; mechanical stir casting and electromagnetic stir casting. Metal matrix composite (MMC) was fabricated using aluminium as a matrix and SiC as reinforcement in varying weight percentages. The wear and frictional properties of the MMC were studied by performing dry sliding wear test using a pin-on-disc wear tester for both types of samples. Wear rate retards with the increase the percentage of reinforcement whereas it improves with the addition of normal force. At same time frictional coefficient upsurges by increasing the normal force and percentage of reinforcement. Increasing percentage of reinforcement and using electromagnetic stir casting process obtained the higher frictional coefficient and lower wear rate.
2017-09-19
Technical Paper
2017-01-2050
Piotr Synaszko, Michal Salacinski, Patryk Ciezak
Abstract The work concerns the selection of measurement parameters for selected non-destructive testing methods of Mi helicopter rotor blades after repair. Considered repair cases involve metal cracks in the sandwich skin and repair damage of honeycomb structure (puncture, dent). In the event of a crack, repair is performed by applying a composite-metal repair package. In case of damage of the core, its broken piece is replaced by a new one and then applied the same metal-composite package as in the case of crack repair. The present work focuses on detecting disbond between skin and core below repair patch and cracks under the repair package. Detecting cracks and assessing their length is important because the repair technology provides the repair package without removing of cracked part of skin. Authors have used laser shearography and C-scan methods for MIA and ET.
2017-09-19
Technical Paper
2017-01-2058
Francesco Noziglia, Paolo Rigato, Enrico Cestino, Giacomo Frulla, Alfredo Arias-Montano
Abstract Innovative aircraft design studies have noted that uncertainty effects could become significant and greatly emphasized during the conceptual design phases due to the scarcity of information about the new aero-structure being designed. The introduction of these effects in design methodologies are strongly recommended in order to perform a consistent evaluation of structural integrity. The benefit to run a Robust Optimization is the opportunity to take into account uncertainties inside the optimization process obtaining a set of robust solutions. A major drawback of performing Robust Multi-Objective Optimization is the computational time required. The proposed research focus on the reduction of the computational time using mathematic and computational techniques. In the paper, a generalized approach to operate a Robust Multi-Objective Optimization (RMOO) for Aerospace structure using MSC software Patran/Nastran to evaluate the Objectives Function, is proposed.
2017-09-19
Technical Paper
2017-01-2087
Peter Mueller-Hummel, Alex Hjorten
Abstract This article characterizes the special features of machining composite in comparison to machining metal. Simplified theoretic models will demonstrate how CFRP should be machined without delamination, burn marks and cutting tool breakages. Different strategies can be chosen depending on the material removal rate. The paper will present, based on this analytical approach, how milling cutters should be designed for optimal trimming, and how a drill should be designed in order to avoid the entrance, inner and exit delamination. While entrance and exit delamination is well understood, the paper will focus more to the delamination inside the bore. The appearance and the avoidance of the so called "Volcano Effect" and the reason why holes in composite becomes smaller after a couple of days will be explained. The comparison between 4 different cutting tool technologies will prove and give a better understanding how to use this theoretical approach.
2017-09-19
Journal Article
2017-01-2142
Brandon Mahoney, Jamie Marshall, Thomas Black, Dennis Moxley
The supersession of metallic alloys with lightweight, high-strength composites is popular in the aircraft industry. However, aviation electronic enclosures for large format batteries and high power conversion electronics are still primarily made of aluminum alloys. These aluminum enclosures have attractive properties regrading structural integrity for the heavy internal parts, electromagnetic interference (EMI) suppression, electrical bonding for the internal cells, and/or electronics and failure containment. This paper details a lightweight carbon fiber composite chassis developed at Meggitt Sensing Systems (MSS) Securaplane, with a copper metallic mesh co-cured onto the internal surfaces resulting in a 50% reduction in weight when compared to its aluminum counterpart. In addition to significant weight reduction, it provides equal or improved performance with respect to EMI, structural and flammability performance.
2017-09-19
Technical Paper
2017-01-2130
Yucheng Liu, Thomas Sippel, Ge He
Abstract Oven and flame tests were designed and conducted to evaluate the heat resistance of a ceramic coating material, Cerakote C-7700Q, and evaluate its viability to replace the intumescent coating as one painting material for helicopter engine cowlings. The test results showed that the currently used painting scheme of the engine cowlings failed the 220°C oven test while after replacing the epoxy seal coat with the Cerakote, the new painting system passed the 220°C test in regards to painting bubbling. This study explained why serious appearance defects occurred in the inner skin of the engine cowling when the aircraft is hovering and suggested that one most time- and cost-effective solution is to repaint the current engine cowlings with a new three coating system of Cerakote, surface protection HS7072-622, and intumescent paint as a fireproof lacquer.
2017-09-19
Technical Paper
2017-01-2149
Cameron S. Gillespie
Abstract As carbon fiber reinforced plastics (CFRP) become more integrated into the design of large single piece aircraft structures, aircraft manufacturers are demanding higher speed and efficiency in Automated Fiber Placement (AFP) deposition systems. To facilitate the manufacturing of large surface area and low contour parts (wing skins, in this case) at a high production rate, Electroimpact has developed a new AFP head consisting of 20 1.5 inch wide pre-impregnated carbon tows. The new head design has been named the ‘OH20’, short for ‘One and a Half Inch, 20 Tows’. This AFP head format creates a deposition swath over 30 inches wide when all 20 tows are active. A total of four of these AFP heads have been integrated with a quick change robotic tool changer on two high speed, high acceleration, and high accuracy moving beam gantries.
2017-09-19
Journal Article
2017-01-2152
Sean Taklimi, Ali Ghazinezami, Kim Cluff PhD, Davood Askari
Abstract The use of nanomaterials and nanostructures have been revolutionizing the advancements of science and technology in various engineering and medical fields. As an example, Carbon Nanotubes (CNTs) have been extensively used for the improvement of mechanical, thermal, electrical, magnetic, and deteriorative properties of traditional composite materials for applications in high-performance structures. The exceptional materials properties of CNTs (i.e., mechanical, magnetic, thermal, and electrical) have introduced them as promising candidates for reinforcement of traditional composites. Most structural configurations of CNTs provide superior material properties; however, their geometrical shapes can deliver different features and characteristics. As one of the unique geometrical configurations, helical CNTs have a great potential for improvement of mechanical, thermal, and electrical properties of polymeric resin composites.
2017-09-19
Journal Article
2017-01-2153
Patrick Land, Petros Stavroulakis, Richard Crossley, Patrick Bointon, Harvey Brookes, Jon Wright, Svetan Ratchev, David Branson
Abstract Inspection of Composite panels is vital to the assessment of their ability to be fit for purpose. Conventional methods such as X-ray CT and Ultrasonic scanning can be used, however, these are often expensive and time consuming processes. In this paper we investigate the use of off-the-shelf Non-Destructive Test, NDT, equipment utilizing Fringe projection hardware and open source software to rapidly evaluate a series of composite panels. These results are then verified using destructive analysis of the panels to prove the reliability of the rapid NDT methods for use with carbon composite panels. This process allows us to quickly identify regions of geometric intolerance or formed defects without the use of expensive sub-surface scanning systems, enabling a fast and cost effective initial part evaluation system. The focus of this testing series is on 6mm thick pre-preg carbon-epoxy composite laminates that have been laid up using AFP and formed using TRF.
2017-09-19
Technical Paper
2017-01-2086
Justin Lo
Abstract The fast growth of air traffic and the need for lighter and more fuel efficient aircraft is driving the ramp-up of important new aircraft programs. These increases in production rates are driving manufacturers to seek out robust and reliable installation systems. They must also adapt to the unique requirements of composite materials that now have an increasingly important place in the aerospace industry. Moreover, environmental constraints continue to evolve and drive new regulations, such as REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) in Europe. As an example, this regulation is leading to the adoption of non-chromate surface treatments and paints for most applications. The legacy generation of fasteners does not comply with all of these new requirements.
2017-09-19
Journal Article
2017-01-2154
Alan Hiken
Abstract A review of critical technologies and manufacturing advances that have enabled the evolution of the composite fuselage is described. The author’s perspective on several development, military, and production programs that have influenced and affected the current state of commercial fuselage production is presented. The enabling technologies and current approaches being used for wide body aircraft fuselage fabrication and the potential reasons why are addressed. Some questions about the future of composite fuselage are posed based on the lessons learned from today and yesterday.
2017-09-17
Journal Article
2017-01-2481
Vishal Mahale, Jayashree Bijwe, Sujeet Sinha
Abstract Potassium titanate (KT) fibers/whiskers are used as a functional filler for partial replacement of asbestos in NAO friction materials (FMs). Based on little information reported in open literature; its exact role is not well defined since some papers claim it as the booster for resistance to fade (FR), or wear (WR) and sometimes as damper for friction fluctuations. Interestingly, KT fibers and whiskers (but not powder) are proved as carcinogens by the International Agency for Research on Cancer (IARC). However, hardly any efforts are reported on exploration of influence of KT powder and its optimum amount in NAO FMs (realistic composites) in the literature. Hence a series of five realistic multi-ingredient compositions in the form of brake-pads with similar parent composition but varying in the content of KT powder from 0 to 15 wt% (in the steps of 3) were developed. These composites were characterized for physical, mechanical, chemical and tribological performance.
2017-08-25
Technical Paper
2017-01-5005
Subhash Hanmant Bhosale, Ashish Kumar Sahu, Suhas Kangde, Abhijit Londhe
Abstract In today’s cost competitive environment, automotive companies are moving towards lightweight materials for reducing carbon footprint, increasing fuel economy and cost benefits. Fiber reinforced plastics (FRP) is one of the most attractive option considering its high strength to weight ratio. The advantage of continuous FRP composites is tailorability according to different performance requirements. This paper will focus on finite element analysis and optimization of automotive hood structure made up of continuous carbon fiber reinforced composite with epoxy resin based matrix. Composite hood structure is analyzed using detailed orthotropic composite laminate models and an appropriate composite material failure theory. Strength of FRPs is maneuvered by orientations of the fiber plies. Considering this, stack-up sequence optimization is performed considering bending, torsional stiffness and fundamental modes in dynamic analysis.
2017-08-09
Tech Insights
TI-0001
As the aerospace industry continues on its quest for ever-increased efficiency, so goes the quest for ever-more composite content on aircraft. And with it, more opportunities to repair it. Typical composite panel fiber reinforcements are carbon, aramid, and fiberglass. The machining techniques for these typical composite materials are similar, but minor differences exist, such as the style of cutting tool or drill bit. Automated drilling methods that may be used during original manufacture are rarely used in typical composite repair situations.
2017-07-10
Technical Paper
2017-28-1988
G Ramanjaneyulu, R Rajendran
Abstract POM/Graphite and POM/MoS2 composites were prepared using twin screw extruder for 2 and 6% compositions of fillers. The samples for impact test were prepared by injection moulding machine. The samples were studied for impact strength and wear loss. The wear test of the samples was carried out using pin on disc wear testing machine at various loads. Impact test of the samples was carried out by impact testing machine. The wear of the POM/MoS2 composites decreased compared to POM/Graphite composites. The impact results revealed that significant improvement in the impact strength for graphite and MoS2 fillers compared to pure POM. The microstructural study was conducted for wear samples to know the wear behavior of POM composites.
2017-07-10
Technical Paper
2017-28-1986
Dinesh Paulraj, S.S.M Abdul Majeed, R Rajendran
Abstract In this study, the TiO2 nano particles are incorporated with A356 aluminium to form a Metal Matrix Composite (MMC) to be utilized in aerospace, marine, military and automotive applications. Stir casting method was used for producing the metal matrix composites. A356 aluminium was reinforced with various weight percentage (wt%) of TiO2 under 10 minutes holding time and 450 rpm stirring speed. Mechanical properties such as tensile strength and hardness of the Metal Matrix Composite were tested. Using Scanning electron microscope the surface morphology and composition of the manufactured specimens were studied. Energy dispersive spectroscopic analysis was carried out to study the elemental composition of the MMC. The mechanical tests reveal that there is a significant enhancement in the properties of the composites with 1.5 wt% of TiO2.
2017-07-10
Technical Paper
2017-28-1984
Naveed Hussain
Abstract Importance of fibers as reinforcements in metal matrices has long been recognized. It is only because of this realization that many industries like aerospace and to some extent the automobile industry relies entirely on advanced composite materials for their conflicting demands of high performance and lightweight materials. However most of the work in these areas has been limited or confined to patents created by the defense and automotive sectors. The efforts to commercialize these materials have been restricted due to high cost of the reinforcements and the manufacturing processes used. In this work an attempt has been made to infiltrate the Carbon fibers by imparting Nickel and Salt based coatings to fiber surfaces with commercial purity aluminum and A356 alloy. Infiltration has been performed in ambient atmosphere and also under vacuum. The carbon fibers have been successfully infiltrated with K2ZrF6 salt coatings and were hot pressed to required shapes.
2017-07-10
Technical Paper
2017-28-1985
Hemasunder Banka, Radhika Muluka, Vikram Reddy
Abstract Conventional materials like steel, brass, aluminum etc will fail without any indication, cracks initiation, propagation, will takes place with a short span. Now-a-days to overcome these problem, conventional materials are replaced by hybrid composite material. Not only have this conventional material failed to meet the requirement of high technology applications, like space applications and marine applications and structural applications in order to meet the above requirements new materials are being searched. Hybrid composites materials found to the best alternative with its unique capacity of designing the materials to give required properties and light weight. This paper aims to preparing hybrid composite using artificial fibers. Epoxy as resin and glass fiber as fiber for artificial hybrid composite to make a laminate for preparing leaf spring.
2017-07-10
Technical Paper
2017-28-1987
Vigneshwaran K, Palanivendhan Murugadoss, K Gokul
Abstract The main objective is to Extraction of cellulose fibers using mechanical ball milling process and chemical treatment methods. The fibers are incorporated with an epoxy matrix to make composite plates. Mechanical properties such as tensile strength, flexural strength, and impact energy are evaluated. Ball milling is the mechanical extraction method of producing nano size powder. The increase in milling process results in the chance of occurring nanofibers. The ball milling process is carried out without any chemical treatment process. In chemical treatment methods, three different kinds of treatment are performed namely sodium hypochlorite, sulphuric acid and acetic acid. Using hand layup methods these fibers are incorporated into the epoxy matrix to fabricate composite plates. In my study nanosized fiber is not obtained, only 28 micron fibers are converted into 3-4 microns.
2017-06-05
Technical Paper
2017-01-1881
Charles Moritz, Satyajeet Deshpande
Abstract As part of the update process to SAE J1637, Laboratory Measurement of the Composite Vibration Damping Properties of Materials on a Supporting Steel Bar, the Acoustical Materials Committee commissioned a round robin study to determine the current laboratory-to-laboratory variation, and to better understand best practices for composite loss factor measurements. Guidance within the current standard from a previous round robin study indicates a coefficient of variation of 35% for laboratory-to-laboratory measurements. It was hoped that current instrumentation and test practices would yield lower variability. Over the course of 2 years, 8 laboratories tested 4 bars, three damped steel bars and one bare steel bar. These bars were tested at -20°C, -5°C, 10°C, 25°C, 40°C, and 55°C. The damping materials were intentionally selected to provide low damping, moderate damping, and high damping as difficulties in determining the composite loss increase with increased damping.
2017-06-05
Journal Article
2017-01-1813
James M. Jonza, Thomas Herdtle, Jeffrey Kalish, Ronald Gerdes, Taewook Yoo, Georg Eichhorn
Abstract The aerospace industry has employed sandwich composite panels (stiff skins and lightweight cores) for over fifty years. It is a very efficient structure for rigidity per unit weight. For the automobile industry, we have developed novel thermoplastic composite panels that may be heated and shaped by compression molding or thermoforming with cycle times commensurate with automotive manufacturing line build rates. These panels are also readily recycled at the end of their service life. As vehicles become lighter to meet carbon dioxide emission targets, it becomes more challenging to maintain the same level of quietness in the vehicle interior. Panels with interconnected honeycomb cells and perforations in one skin have been developed to absorb specific noise frequencies. The absorption results from a combination and interaction of Helmholtz and quarter wave resonators.
2017-03-28
Technical Paper
2017-01-1467
Ashok Mache, Anindya Deb, Clifford Chou
Abstract There has been a keen interest in recent times on implementation of lightweight materials in vehicles to bring down the unladen weight of a vehicle for enhancing fuel efficiency. Fiber-reinforced composites comprise a class of such materials. As sustainability is also a preoccupation of current product development engineers including vehicle designers, bio-composites based on natural fibers are receiving a special attention. Keeping these motivations of lower effective density, environment friendliness and occupational safety in mind, woven jute fabric based composites have been recently studied as potential alternatives to glass fiber composites for structural applications in automobiles. In the past, mechanical characterization of jute-polyester composites were restricted to obtaining their stress-strain behaviors under quasi-static conditions.
2017-03-28
Technical Paper
2017-01-0502
Mingde Ding, Jiancai Liu, Jianbo Su, Zhong Su, Bo Liu, Ligang Wang
Abstract Now weight reduction is increasingly needed in automotive industry to improve fuel efficiency and to reduce emission. Various lightweight technologies have been used to vehicles. Because of its heavy weight and complex shape, IP carrier tends to be integration and weight intensive. Therefore lightweight is necessary for IP carrier. This paper lists the fourth lightweight technologies used for IP carrier by now, which are Magnesium alloy part, Aluminum alloy part, Hybrid composite part, Composite material injection part. For magnesium alloy part and aluminum alloy part, they have been mass produced for some years. The hybrid composite part has been researched for some years. Recently, the injection composite part has been researched and some parts have been developed and tested. By outlining the design, manufacturing, weight reduction and cost of these lightweight technologies, this paper fully analyzed these used technologies.
2017-03-28
Technical Paper
2017-01-0503
Ahmad Waqar Tehami, Kamran Asim, Shahzad Sarwar
Abstract Fiber reinforced laminated materials are becoming popular in applications involving protection against impact loading. Laminates offer many advantages over metal plates in these applications. Laminates are normally non-ricochet, thus offering greater protection against projectiles. Laminates are also lighter in weight and less expensive as compared to the metal panels. In this study, laminated materials were fabricated from two different types of fibers which included short fibers and random fibers. Epoxy and polyester were used as the resin materials in the production of different types of laminates. Test samples were tested according to the available standards to investigate the impact toughness and ballistic resistance of these laminates. Experimental results showed that random fibers and polyester resin absorbed more energy as compared to short fibers and epoxy resin, respectively.
2017-03-28
Technical Paper
2017-01-0504
Anthony Berejka, Dan Montoney, Dan Dispenza, Len Poveromo, Rick Galloway, Mark Driscoll, Marshall Cleland
Abstract Having demonstrated the feasibility of using X-rays derived from high current industrial electron beam accelerators (EB) to cure the matrices of carbon fiber composites and then scaled this up to cure large sized, non-structural automobile components, performance car hoods, the New York State Vehicle Composites Program had a chassis designed, a cured epoxy mold made and then the chassis matrix cured using X-rays with a formulated radiation responsive matrix material. A feasibility study had shown how X-rays could cure through materials embedded within the composite layers, such as metal inserts that could be used for mechanical fastening without fracturing the composite. In producing X-ray cured hoods, the power consumption for X-ray curing was found to be more than 20% lower than that needed for autoclave curing the same sized hoods using conventional thermosetting pre-pregs. More significant was the time-to-cure.
2017-03-28
Technical Paper
2017-01-0499
Mingde Ding, Jiancai Liu PhD, Jianbo Su Sr, Zhiyuan He Sr, Benhong Tan Sr, Ligang Wang
Abstract Because of their high specific stiffness and strength, composite materials have been used in the structural of vehicles to provide a competitive advantage of through weight reduction while maintaining or even increasing functionality. Composite materials have been used for IP carrier which forms the skeleton of the cockpit and provides the base architecture off of which IP components are attached and function. Specially, composite materials using injection molding process have been used to develop IP carrier recently, due to high level of styling flexibility by that can achieve high degree integration and simplicity of process. However, for injection part especially for large part would deform largely. Consequently, deformation controlling is very important for large composite part that used injection molding. In this study mold flow analysis was conducted on the composite IP carrier structure which gets from the topology optimization result.
2017-03-28
Technical Paper
2017-01-0465
HaiYan Yu, Siji Chen
Abstract Carbon Fiber Reinforced Plastic (CFRP) tube is an important material for the lightweight design of automotive structures. Simulation method of CFRP thin-walled tubes subjected to axial compression using MAT54 in LS-DYNA was investigated. Based on the two-layer shell model combined with MAT54, failure strategy and the parameters sensitivity of the model were discussed in detail. Then the simulation model was verified by using duplicate specimens comprised of carbon fiber/epoxy unidirectional prepreg tape. Furthermore, the modeling methods of crush trigger and different types of loading speed were analyzed. In addition, based on the method of equal energy absorption, energy absorption performance of thin-walled circular and square tubes made from four materials including mild steel, high strength steel, aluminum alloy and CFRP were also compared.
2017-03-28
Technical Paper
2017-01-0459
Salah H. R. Ali, Badr S. N. Azzam, T. A. Osman, A. M. Moustafa
Abstract The frictional composite is an important material in braking system for automotive, trucks or heavy-duty vehicles. In this paper, a proposed frictional composite material has been developed to achieve the ISO requirements for heavy-duty vehicle brakes. This new frictional material has been fabricated with various compositions. Tribological, chemical, mechanical, thermal conductivity and acoustic noise level tests have measure its performance compared to other two commercial samples under certain operating conditions. Surface characteristics of selected samples have been performed using white light optical microscopy (WLOM) in 2D images to insure the material homogeneity. Additionally, surface roughness analyses using atomic force microscopy (AFM) into 2D and 3D images before and after frictional operation have been investigated.
2017-03-28
Journal Article
2017-01-0501
Sajiree Vaidya, Naga Sai Chakravart Velamakuri, Piyush Agarwal, Srikanth Pilla, David Schmueser
Abstract In modern passenger vehicles, A-pillar plays an important role in its passive safety by minimizing the deformation of passenger compartment during the crash. To meet various crash requirements, as well as sometimes due to demand of vehicle styling, A-pillar cross section of modern vehicles is generally wider. This wider cross section acts as an increased obstruction to the field of vision of the driver. It is considered detrimental for the safety of road users. The current work proposes an innovative design solution to reduce the obstruction angle due to an A-pillar. It also addresses the weight reduction objective. This is done by utilizing the noble properties of Carbon Fiber Reinforced Polymers (CFRP). Carbon Fiber Reinforced Polymers (CFRP) offer flexibility for complex design. Due to high specific strength and stiffness, CFRP's are suitable candidate for design considerations presented in this study.
2017-03-28
Journal Article
2017-01-0477
Harish M. Rao, Jidong Kang, Garret Huff, Katherine Avery, Xuming Su
Abstract Tensile and fatigue properties of continuous braided carbon fiber reinforced polymer (CFRP) composite to AA6111 self-piercing riveted (SPR) lap shear joints are presented. Rivets were inserted at two target head heights separated by 0.3 mm. Even within the narrow range of head heights considered, the flushness of the rivet head was found to have a dominant effect on both the monotonic and fatigue properties of the lap shear SPR joints. Joints created with a flush head resulted in a greater degree of fiber breakage in the top ply of the CFRP laminate, which resulted in lower lap shear failure load as compared to SPR joints produced with a proud rivet head. Irrespective of the lap shear failure load, rivet pullout was the most common failure mode observed for both rivet head heights. In fatigue tests, the SPR joints produced with a proud head exhibited higher fatigue life compared to SPR joints produced with a flush head.
Viewing 1 to 30 of 1529

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