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In February 1976, work commenced to automate the methods contained in the USAF Stability and Control DATCOM, specifically those contained in sections 4, 5, 6 and 7.The work was performed by the McDonnell Douglas Corporation under contract with the United States Air Force in conjunction with engineers at the Air Force Flight Dynamics Laboratory in Wright-Patterson Air Force Base.
The vertical stabilizer is the fixed vertical surface of the empennage. A vertical stabilizer or tail fin [1] [2] is the static part of the vertical tail of an aircraft. [1] The term is commonly applied to the assembly of both this fixed surface and one or more movable rudders hinged to it. Their role is to provide control, stability and trim ...
A Boeing 737 uses an adjustable stabilizer, moved by a jackscrew, to provide the required pitch trim forces. Generic stabilizer illustrated. A horizontal stabilizer is used to maintain the aircraft in longitudinal balance, or trim: [3] it exerts a vertical force at a distance so the summation of pitch moments about the center of gravity is zero. [4]
Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]
is known as the tail volume ratio. Its coefficient, the ratio of the two lift derivatives, has values in the range of 0.50 to 0.65 for typical configurations. [ 15 ] [ page needed ] Hence the expression for h may be written more compactly, though somewhat approximately, as:
Logo of Eurocode 2 An example of a concrete structure. In the Eurocode series of European standards (EN) related to construction, Eurocode 2: Design of concrete structures (abbreviated EN 1992 or, informally, EC 2) specifies technical rules for the design of concrete, reinforced concrete and prestressed concrete structures, using the limit state design philosophy.
(2) The thermal expansion coefficients of concrete and steel are so close (1.0 × 10 −5 to 1.5 × 10 −5 for concrete and 1.2 × 10 −5 for steel) that the thermal stress-induced damage to the bond between the two components can be prevented. (3) Concrete can protect the embedded steel from corrosion and high-temperature induced softening.
Terzaghi's principle applies well to porous materials whose solid constituents are incompressible - soil, for example, is composed of grains of incompressible silica so that the volume change in soil during consolidation is due solely to the rearrangement of these constituents with respect to one another.