AGATE DESIGNSTRUCTURES |
EXECUTIVE SUMMARY | The structural design
, Figures 2a and 2b,
of the VenTure stresses efficiency and simplicity through the use
of composite materials. Superseding conventional metal airframes,
composite airframes provide resistance to loads at a reduced weight through
high stiffness-to-weight and strength-to-weight ratios while simplifying
structural layout manufacturing, increasing structural integrity, and minimizing
weight. Complete details of this advanced structural design
are presented in Appendix E.
The composite structural design was optimized to facilitate ease of manufacture. Decreasing the number of structural members simplifies the overall structure. The carbon-nomex sandwich structure, used in fuselage frames, longerons, wing spars, and the wing skin, is more than capable of sustaining shear, tension, and compression loads due to bending; this eliminates excessive longeron and stringer part count. The aircraft’s structural design was simplified by coordinating assembly techniques with the VenTure's manufacturing division. The fuselage skin is laid-up in one-piece with a mixture of woven and chopped/spray fiberglass layers. Direct molding of structural appendages to the fuselage eliminates the need for their fastening during assembly. Bonding of composite materials reduces the need for metal fasteners, further decreasing part count and assembly processes. The structural integrity of the VenTure has not been compromised by its simple and efficient design. FAR 23 standards for positive and negative load factor limits validate the design of the VenTure, Figure 3. The chosen materials are tested and proven for aircraft and watercraft utility. Fail-safe capabilities have been incorporated into a crashworthy structure. Fourteen watertight compartments located within the hull, sponsons, and wings supply floatation in the event of skin damage. An aluminum mesh has also been embedded in the aircraft skin as necessary to provide protection from lightning. The take-off gross weight, TOGW, of the VenTure is 2890 lb. Extensive use of composite materials make the TOGW of the amphibious VenTure comparable to its land based counterparts with which it was designed to compete (Table 1). The VenTure's use of composite materials in conjunction
with a composite-optimized manufacturing process has resulted in a high
performance aircraft which will out-perform current land based planes while
possessing the go-anywhere capability of an amphibian, making the VenTure
the sport utility vehicle of the air.
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