Advances in Aerospace Materials and Structures最新文献

{"title":"Overview of AGATE Advanced Materials Research","authors":"J. Tomblin","doi":"10.1115/imece1999-0148","DOIUrl":"https://doi.org/10.1115/imece1999-0148","url":null,"abstract":"\u0000 The Advanced General Aviation Transport Experiments (AGATE) Consortium is a cost-sharing industry-university-government partnership initiated by NASA to create the technological basis for revitalization of the U.S. general aviation industry. It was founded in 1994 to develop affordable new technology as well as the industry standards and certification methods for airframe, cockpit, flight training systems, and airspace infrastructure for next generation single pilot, 4–6 place, near all-weather light airplanes. The AGATE consortium has more than 70 members from industry, universities, the FAA, and other government agencies.\u0000 With respect to the advanced materials program within AGATE, the government-industry-academia program is directed toward the creation of material allowables that will be approved by the FAA for qualification of composite airframes — the first two being the Cirrus SR20 from Cirrus Design Corporation of Duluth, MN and the Lancair Columbia 300 from Pacific Aviation Composites of Bend, OR. These aircraft will be the first two all composite, four-seat AGATE-type airplanes to be certified in the United States. AGATE members Lancair, Cirrus Design, Cessna Aircraft, Raytheon Aircraft, Global Aircraft, Stoddard-Hamilton and Simula Technologies are contributing members in the program that promises to increase the level of sharing between competitors for the benefit of the entire general aviation industry.\u0000 One major goal of the advanced materials program is produce FAA approved certification methods for the use of composite materials within the general aviation community. A recently published document entitled “Material Qualification Methodology for Epoxy-Based Prepreg Composite Material Systems” has been approved which describes an acceptable program to substantiate that the materials and processes employed meet FAA requirements for a selected material system. This is the first FAA public document which “standardizes” the procedure for qualifying a composite material system which follows guidelines set forth by the MIL-HDBK-17 committee. These requirements apply to the original material qualification. Once certified, changes to the material, process tooling, and/or facility require a review and repetition of some (or all) of these tests may be required. The plan gives specific information about the qualification program for epoxy-based pre-impregnated carbon or fiberglass unidirectional tape and pre-impregnated carbon or fiberglass woven fabric cured and processed at or above 240 degrees Fahrenheit. Specifically, this plan covers qualification methodology for no-bleed prepreg systems manufactured using vacuum bag molding.\u0000 The properties of traditional materials — aluminum, steel, etc. — have long been accepted by the FAA in the design of airframes. These “allowables” mean the designer does not have to test every part to destruction, which is a very expensive, time-consuming process, but may use these allowable to substantiate the d","PeriodicalId":240121,"journal":{"name":"Advances in Aerospace Materials and Structures","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126396722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Composite Materials Use: A Particular Case of Safety-Related Service Water Pipes","authors":"Th. Le Courtois, M. Pays","doi":"10.1115/imece1999-0142","DOIUrl":"https://doi.org/10.1115/imece1999-0142","url":null,"abstract":"\u0000 This paper shows the present and future uses of composite materials in French nuclear and fossil-fuel power plants. It sets the EDF composite materials market in the general composite materials market and shows the great interest that EDF takes in these materials which are corrosion resistant in most fluid handling applications.\u0000 Electricité de France has decided to install composite materials in service water piping in its nuclear power plant (PWR) at Civaux (West of France) and for the first time in France, in safety-related applications. Our requirements are thus much more severe than is usually the case and the choices (for the basic materials, the manufacturing, the design rules, and the non destructive testing methods) have to be justified before our Safety Authorities.\u0000 A wide range of studies has been performed about the durability, the control and damage mechanisms of those materials under service conditions among an ongoing Research and Development project. The main results are presented under the following headlines:\u0000 • Selection of basic materials and manufacturing processes,\u0000 • Aging processes (mechanical behavior during « lifetime »),\u0000 • Design rules,\u0000 • Non destructive examination during manufacturing process and during operation.\u0000 The studies have been focused on epoxy glass pipings: the actual application is the circuits for the nuclear power plant in Civaux, the supplies and installation of the pipes have largely begun.\u0000 We underline the importance of strong quality insurance policy requirements towards production and installation companies. We present a study of the use of composite pipes in power plants (hydraulic, fossil fuel, and nuclear) in France whether it be safety related or non safety-related applications. We present the different technical solutions for materials and manufacturing processes and an economic comparison between steel and composite pipes. Finally, we give the general conclusions of the R&D program.","PeriodicalId":240121,"journal":{"name":"Advances in Aerospace Materials and Structures","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125951298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precise Design and Analysis of Wet Layup Composite Repairs","authors":"Gregory A. Kress","doi":"10.1115/imece1999-0151","DOIUrl":"https://doi.org/10.1115/imece1999-0151","url":null,"abstract":"\u0000 The increasing size and cost of composite structures combined with the increased loading requirements placed on such components has heightened the need for performing durable and thoroughly analyzed composite repairs. Precise applications of composite repairs possess many difficulties from both a maintenance and engineering standpoint. The composite repair engineer is often limited by the repair materials and processing equipment that are available, the data to define the loads placed on the structure, and physical limitations such as the inability to remove a panel from the aircraft, heat sinks, and underlying structure. This presentation describes the repair configuration, materials and analysis techniques for performing the precise design and analysis of wet layup composite repairs.”","PeriodicalId":240121,"journal":{"name":"Advances in Aerospace Materials and Structures","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132296751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Microwave Heating for Adhesive Joining","authors":"E. Thostenson, T. Chou","doi":"10.1115/imece1999-0137","DOIUrl":"https://doi.org/10.1115/imece1999-0137","url":null,"abstract":"\u0000 In conventional joining of composite materials and sandwich structures, reductions in processing time are limited by inefficient heat transfer. In conventional processing the thermal energy must diffuse through the composite layers to heat the joint interface and cure the thermosetting adhesive, and this outside-in process of heating results in excessive processing times and wasted energy. The purpose of the current work is to examine microwave heating as an alternative to conventional heating for joining of composite structures. Through proper material selection, microwaves are able to penetrate the substrate materials and cure the adhesives in-situ. Selective heating with microwaves is achieved by incorporating interlayer materials that have high dielectric loss properties relative to the substrate materials. In this study, a processing window for elevated temperature curing of an epoxy paste adhesive system (HYSOL EA 9359.3) was developed and composite joint systems were manufactured using conventional and microwave techniques and tested in shear. Microwave curing resulted in both enhanced shear strength and less scatter in experimental data.","PeriodicalId":240121,"journal":{"name":"Advances in Aerospace Materials and Structures","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126344227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability of Long Cylindrical Sandwich Shells With Dissimilar Facings Subjected to a Lateral Pressure","authors":"V. Birman, G. Simitses","doi":"10.1115/imece1999-0133","DOIUrl":"https://doi.org/10.1115/imece1999-0133","url":null,"abstract":"\u0000 The paper presents the analysis of buckling and initial postbuckling behavior of long cylindrical sandwich shells subjected to a lateral pressure. The shells considered in the paper have dissimilar facings reflecting a demand to enhance impact resistance and damage tolerance of the facing exposed to external loads and hostile environments that are typical in applications. The shell being long, its central section remains in the state of plane strain prior to and after buckling. The solution includes the analysis of prebuckling deformations and linear and nonlinear buckling problems. It is shown that prebuckling deformations affect postbuckling shell behavior but they do not affect the linear (upper) buckling pressure. Numerical results presented in the paper illustrate that a moderate redistribution of the layers between the facings results in a limited reduction of the buckling pressure compared to the case of symmetric facings.","PeriodicalId":240121,"journal":{"name":"Advances in Aerospace Materials and Structures","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126662640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Past, Present and Future Composite Structures Applications in Rotorcraft","authors":"C. Rousseau, A. Dobyns, Pierre J. A. Minguet","doi":"10.1115/imece1999-0147","DOIUrl":"https://doi.org/10.1115/imece1999-0147","url":null,"abstract":"The rotorcraft industry is a roughly $5B/year segment of aerospace, with a 4:1 military to civil sales ratio, that delivers on the order of 5000–6000 aircraft per year. The earliest rotorcraft had composite primary structure: bonded wooden main and tail rotor blades. The first advanced composite main rotor (M/R) and tail rotor blades (bonded glass/epoxy D-spars, honeycomb afterbodies, and fabric skins) went into production in the early ’70’s. Thus, the rotorcraft industry has been designing and certifying nonredundant bonded primary composite structure for over 25 years. More recent design innovations for rotor components include 4-inch-thick solid molded bearingless M/R hubs and yokes (joining the blades to the mast) and a 1.5-inch-thick complex curvature fiber placed carbon grip for the Bell/Boeing MV-22 Osprey tiltrotor. With roughly 50% of its empty weight consisting of glass and carbon reinforced composites, the V-22 probably has the highest weight-percentage of composites of any manned military production aircraft. This degree of composites usage will likely be surpased by the Sikorsky/Boeing RAH-66 Comanche scout/attack helicopter when it goes into production. As with the V-22 and RAH-66, composites are also seeing increased usage in civilian rotorcraft airframes. Specifically, the Bell 427 and MD Helicopter MD900 Explorer light twin helicopters feature all-composite fuselages, while the Bell-Agusta BA609 civil tiltrotor will have carbon epoxy wings, fuselage and empennage much like the V-22. In the future, composite structural applications will become more widespread as designers gain insight and confidence. Repair, maintenance and support of these structures will become the focus of much engineering R&D effort.","PeriodicalId":240121,"journal":{"name":"Advances in Aerospace Materials and Structures","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126909697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Approach for MMC Component Design","authors":"J. Ahmad, U. Santhosh, G. Newaz, T. Nicholas","doi":"10.1115/imece1999-0146","DOIUrl":"https://doi.org/10.1115/imece1999-0146","url":null,"abstract":"\u0000 Titanium based metal matrix composites (MMCs) with continuous fibers first gained prominence as enabling structural materials for the National Aerospace Plane (NASP). Some of the peculiar deformation and damage characteristics of MMCs were identified, explained, and modeled as part of the NASP program activities in the early 1990s. Much was discovered and learned regarding the behavior of MMCs under a variety of thermal and mechanical load combinations. Analytical and numerical models of deformation and damage were developed and validated. Significant progress was achieved in proper viscoplastic characterization of the matrix materials and micromechanics based deformation and damage modeling of MMCs. These research activities, which actually outlasted the NASP program, resulted in major advances in understanding, characterization, and modeling of MMCs. However, virtually all-modeling activity remained focused on unidirectional loading of MMCs.\u0000 To some extent, virtually all aircraft propulsion system and structural components are subjected to multiaxial stresses. Therefore, while the understanding and the modeling techniques developed under the NASP program represented a major step forward, additional steps were needed to reach a level where models could be used in the design and life prediction of actual components.\u0000 Overlapping NASP related activities, efforts were underway by the major jet engine manufacturers under the Integrated High Performance Turbine Engine Technology (IHPTET) program to design and test propulsion system components involving the use of MMCs. These activities were mainly focused on fabricating and testing metallic rotors with unidirectional MMC inserts. The inserts were toroids of various cross-sections, with fibers along the circumferential direction. Initial sub-component and component level testing of rings and rotors indicated that the existing design and stress analysis methods were inadequate in predicting the deformation and damage behavior of MMCs under biaxial (hoop and radial) stresses.\u0000 Instigated by IHPTET needs, a project was initiated with the following objectives: (a) develop a theory for predicting MMC damage and deformation response under multiaxial stress states caused by general time dependent thermomechanical loading, (b) validate the theory by comparing predictions with laboratory test measurements, and (c) incorporate the theory in a stress analysis procedure that can be used by design engineers. The project was focused on unidirectional titanium based matrix composites with silicon carbide fibers.\u0000 The paper will consist of a summary of progress that has been achieved in the above project. Specifically, outline of a theory for predicting deformation and damage of MMCs under multiaxial stress states will be presented. The theory includes consideration of dominant damage mechanisms associated with titanium matrix composites, processing induced residual stresses, and time, temperature, and strain rate","PeriodicalId":240121,"journal":{"name":"Advances in Aerospace Materials and Structures","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133158613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Active Sandwich Trim Panels for Quieter Aircraft Interior","authors":"J. Q. Sun","doi":"10.1115/imece1999-0138","DOIUrl":"https://doi.org/10.1115/imece1999-0138","url":null,"abstract":"\u0000 Recent research in the area of structural acoustic control for aircraft interior noise suppression has been focused on developing active trim panels. Active trim panels being part of non-critical structures offer many advantages over active controls applied to load critical structures such as aircraft frames and skins. This paper presents a study of active sandwich composite trim panels. The paper first investigates the effect of curvature on the dynamics of the trim panel, and the power transfer between the actuator and the host panel. Experimental data of interior noise control are then presented to demonstrate the application of the active trim panels.","PeriodicalId":240121,"journal":{"name":"Advances in Aerospace Materials and Structures","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125365163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Designing With High Temperature Composites","authors":"R. Miller","doi":"10.1115/imece1999-0149","DOIUrl":"https://doi.org/10.1115/imece1999-0149","url":null,"abstract":"\u0000 Actual and potential composite applications in commercial and military aircraft gas turbine engines range from low temperature graphite/polymer matrix composite (PMC) components at the front of the engine, such as, fan blades, vanes, struts and cases, to high temperature ceramic matrix composite (CMC) turbine, combustor, augmentor, and nozzle components. Currently the “building block” approach is primarily used in the development of composite components for gas turbine engines. Critical issues associated with the design of composite structures for both commercial and military aircraft gas turbine engines are defined. Critical structural components for both commercial and military gas turbine engines are designed to meet strict safety-of-flight requirements established by the FAA and the Air Force/Navy, respectively. Key design requirements established for damage tolerance and durability are emphasized.","PeriodicalId":240121,"journal":{"name":"Advances in Aerospace Materials and Structures","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127603346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transient Response of Laminated Plates Subject to Close Proximity Explosions","authors":"J. Coggin, Jeffrey M. K. Chock, R. Kapania, E. Johnson","doi":"10.1115/imece1999-0144","DOIUrl":"https://doi.org/10.1115/imece1999-0144","url":null,"abstract":"We study the transient response of simply supported composite plates subject to close proximity explosions. Many studies are currently availiable in which the blast load is applied uniformly across the plate; and is described by step, N-pulse, or Friedlander equations. The novel aspect considered here is the case for which the blast pressure is due to a close proximity explosion, and is therefore taken to be both spatially and temporally varying. Two methods for calculating blast pressures are developed for arbitrary blast size and distance. A FORTAN program is described that automates the application of an arbitrary blast load to a generic finite element mesh. Modal superposition and NASTRAN solution procedures are verified for several load types and stacking sequences. Results are obtained within the framework of classical and first order plate theories for a variety of parameters including; stacking sequence, blast size, blast distance, and blast calculation method.","PeriodicalId":240121,"journal":{"name":"Advances in Aerospace Materials and Structures","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131780587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}