3 edition of Fuel containment and damage tolerance in large composite primary aircraft structures found in the catalog.
Fuel containment and damage tolerance in large composite primary aircraft structures
1985 by National Aeronautics and Space Administration, Langley Research Center, For sale by the National Technical Information Service in Hampton, Va, [Springfield, Va .
Written in English
|Series||NASA contractor report -- 166091., NASA contractor report -- NASA CR-166091.|
|Contributions||Langley Research Center.|
|The Physical Object|
These aircraft system requirement trends tend to increase takeoff gross weight, although the traditional performance requirements measuressuch as range, takeoff distance, altitude, and cruise speed, remain the same or call for improvements. Also, composites can be made more resistant to certain types of impact damage through architectural tailoring. New materials and process development to fully exploit the potential of this technology is required for applications in the next generation of civil aircraft. In the example of aircraft, because these structures are often revenue producing, there is an opportunity cost associated with the maintenance of the aircraft lost ticket revenuein addition to the cost of maintenance itself.
Spillman, "The use of variable camber to reduce drag, weight and costs of transport aircraft", Aeronautical Journal, Vol. These processes are described later in this chapter. The advantages of electromagnetic processing to cure polymer-matrix composites include the following Goodman et al. By ensuring the detailed consideration of structural needs throughout the entire lifetime of an aircraft and focusing on the structural integration of needed past capabilities, Smart Intelligent Aircraft Structures will allow aircraft designers to seriously consider conformal morphing technologies. The keys to successful RTM are high-quality tooling, preforms with consistent fiber volumes, and strategic placement of the injection gate and vents to optimize resin flow and remove trapped air. You have much bigger fish to fry.
Automated drilling operations will eventually install approximately 60, fasteners that are today installed by hand. While the development of composites for aerospace applications has traditionally been driven by performance, cost has assumed increasing importance during the past several years. This tends to reduce the tensile and flexural properties. Labor required for placing reinforcements in molds can be high Initial mold costs higher than for one-sided molding processes Control of voids and process variability SOURCE: Blanton et al. A schematic of a diaphragm-forming autoclave is shown in figure Through new design with lower structural weight, they may be able to perform entirely new missions.
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Source: Boeing Figure 6 - Impact of new design and analysis practices on fleet maintenance hours. The resin flows inside the tool cavity, impregnates the reinforcement, and is cured at elevated temperatures.
The 2-D DEM model was constructed to represent a realistic cross section of the Cooke cell with a distribution of four material properties, three that represented the Cooke cell steel, sandstone,square ringsand one representing the proppant.
This module brings finite element analysis into the design of composite structures without the requirement for the user to know much about the techniques and procedures needed to actually perform a finite element analysis from scratch. Successes are evident in terms of significant safety improvements and considerable reductions in service actions on airplanes designed since that time.
There is very little material waste with this method Fanucci et al. Looking to the yearaircraft primary structural weight can be reduced by some 20 to 25 percent and possibly by as much as 50 percent compared to an all metal structure.
Recent studies by the Stim-Lab proppant consortium have indicated that the flow field across a Cooke proppant conductivity testing cell may not be uniform as initially believed which resulted is significantly different conductivity results.
The RFI process has been successfully demonstrated on subcomponent-level structures Markus et al. With the use of a damage tolerance building-block approach comes an interest in developing relationships for scaling test results to reduce testing requirements.
A process that is related to RTM is vacuum-assisted resin infusion in which resin is pulled by vacuum through a high-permeability membrane placed on top of a preform. Since that time, advances in matrix polymer technology have enabled the development of composite systems with improved delamination resistance.
Typical cycle time probably about 10 minutes. This trend has continued on newer airplanes, the NG andfurther enhanced by improvements to the methods and the continuous learning process afforded by fleet observations.
Source: Blanton et al.
Lightning zoning is an ultimately critical step in this process. The benefits of a lower structural weight fraction are quantified by the Breguet range and specific excess-power equations. There is some concern that system costs have been used as an argument for inaction, both with respect to the development of advanced composites and the development of new airplanes using composites.
This tends to reduce the tensile and flexural properties. Although the basic analysis principles employed today are not substantively different from past methods, the tools and processes used have been refined over these past 20 years.
Looking ahead, these processes will seek more efficient use of engineering resources, greater accuracy, and incorporate service experience acquired from an ever-expanding fleet: Materials and basic part fabrication Although much of the current focus in structural materials development is on composites, metals will continue to play a significant role in many areas of the airframe, and for the foreseeable future, will likely remain the dominant Fuel containment and damage tolerance in large composite primary aircraft structures book in short-haul, high-production-rate airplanes.
Quote: I would rather take tensile test coupons from the hatch trim outs also provides a realistic data population for future tank projects. SUMMARY The application of polymeric composites has been an evolutionary process, with increased use as materials and processing technology matured and program needs dictated their use.
Advanced organic composites have been and will continue to be used to improve aircraft range and takeoff gross weight through weight saving. Their development is always a compromise between design and off-design points, referred to a typical mission.
Virtually all work on thermoplastic pultrusion has used prepregs as raw material, including not only solvent-and melt-impregnated materials but also powder-impregnated and commingled materials.
Pultrusion also lends itself to tailorability within the limits of the process. As described earlier in this chapter, interest in continuous-fiber-reinforced thermoplastic-matrix composites has FIGURE Composite pultrusion process. Factors that will reduce the cost of the RTM process Fowler and Phifer, include: low-cost resins and hardeners; optimized preform design and fabrication; automated multipurpose molds; proper selection of fast-curing resins for reduced cure time; mold design for easy mold clean-up; and molded-in cut-outs, holes, and trim to eliminate finish machining operations.
The committee believes that the trend to develop low-cost production processes will be continued for the foreseeable future.Fuel containment and damage tolerance in large composite primary aircraft structures [microform] / Charles F. Griffin National Aeronautics and Space Administration, Langley Research Center Hampton, Va Australian/Harvard Citation.
Griffin, C. F. & Langley Research Center. Damage Tolerance and the Composite Airframe Allen J. Fawcett (ATF/AR) Deriving Composite Primary Structure Design Requirements and Criteria fatigue (no growth with LEF), damage tolerance (VID and large cuts) and static strength (after repair) certification.
L. John Hart-Smith, Douglas Aircraft Company 3DESIGN AND TEST OF LARGE magicechomusic.com DEMONSTRATION COMPONENTS - Bruce L. Bunin, Douglas Aircraft Company 4COMPOSITE WING FUEL CONTAINMENT AND DAMAGE TOLERANCE TECHNOLOGY DEVELOPMENT - Charles F.
Griffin, Lockheed-California Company.Damage Tolerance and the Composite Airframe Allen J. Pdf (ATF/AR) Deriving Composite Primary Structure Design Requirements and Criteria fatigue (no growth with LEF), damage tolerance (VID and large cuts) and static strength (after repair) certification.Fuel containment and damage tolerance in large composite primary aircraft structures.
with fuel containment and damage tolerance of composite wing structures for transport aircraft were.NASA CR Fuel Containment, Lightning Ebook, and Damage Tolerance in Ebook Composite Primary Aircraft Structures [concepts] Regards, Wil Taylor o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown] o For those who believe, no proof is required; for those who cannot believe, no proof is possible.