Airframes & Systems

fixed or retractable TRICYCLE ( Nicht unter dem Flügel, sondern am fuselage) landing gear

Wiederstand; applied per unit area of surface=> internal force inside a structural member => resists deformation N/mm^2 or PSI square Inch

Strength is ability to withstand stress without failure => the maximum stress it can withstand at failure

specific strength is material strength divided by its density

deformation of a structural part is called strain and is expressed as ratio of the deformed structure to the non deformed structure

Tension 2. Compression => 3. bending 4. Shear 5. Torsion 6. Buckling

tends to pull part ==> Zieht an etwas Auseinanderziehen

zusammendrücken == > Landung Gear => Feder => Gewicht Flugzeug

2 Platten sind miteinander verbunden => man zieht an beiden => one layer of a material to slide over an adjacent layer

Moment => Stossen und ziehen ==> when parts are twisted => results fromm a moment

torsion strength of material is its resistance to twisting (drehen)

==> Combination of compression and tension ==> verbiegen => Flügem ==> Grösste Kraft bei einem beam (Balken) is at its attachment (Befestigung) => the material of beam should be located where the stress and resulting strain are high

A320 Lufthansa => compressing structure with length combined with a small thickness ==> Klinking ( ineinander drücken , Dose ineinader stampfen)

result of buckling

temporary deformation due to an applied force that is self-reversing after the force is removed

when the stress is sufficient to permanently deform the material

the rigidity (Steifheit) of an object => resistance against deformation => higher the stiffness, the smaller the deformation due to a given load => Kraft/Deformation = Stiffness ==> Stiffness not to confuse with strength!!

physical property of material which return to their shape after the had been deformed

small deformation when a load is applied

starrheit

mechanical stress in a direction perpendicular to the radius of the item ==> Kabinendruck

the deformation of a material undergoing non-reversible changes of shape in response to applied forces

tendency of a material to deform under permanent stress => more severe to material subjected to heat for long periosds=>increases with temp.=> Turbine: wird grösser und wieder kleiner, jedoch nicht mehr ganz an den Ursprung; wächst immer ein kleines stück

sharp corners or holes ==> cracking (Risse)

When the wing is attached to the fuselage without external bracing.

fueselage wie eine 8

1. truss type or framework type (Gitter) 2. monocoque typ 3. semi-monocoque typ

Struts (Querbalken) carries the weight

Skin, Former, Bulkhead ==> Monocoque the skin carries the weight

Semi Monocoque Stringer, Bulkhead, Frame and Skin ==> Former, Frames and Bulkhead carry the weight

Gerüst

mit Reinforced Shell Structure

Repair by a Doubler

is a kind of bulkhead => fire resistance between engine and the rest of the airplane