Chapter 1 Introduction to Aerospace Structures

Question 1

structure

Answer 1

any assemblage of materials that is intended to sustain loads

aerospace structure is called airframe

functions:
1. carry the loads safely
2. provide proper shape
3. provide proper stiffness (extent to which object resists deformations)

Question 2

development of an aerospace vehicle

Answer 2

1. conceptual design -> system requirements review (SRR)
2. preliminary design -> preliminary requirements preview (PDR)
3. detailed design (detailed sizing, stress report) -> critical requirements review (CDR)
4. certification -> first flight -> entry into service (EIS)
5. in service

reviews are conducted by external experts

Question 3

MAST, MAFT

Answer 3

MAST: major airframe static test
MAFT: major airframe fatigue test

tests conducted during certification phase

to fly in service for 10h, you have to test the plane for 20h

Question 4

requirements of aircraft structures

Answer 4

low costs, in-service aspects, low weight, good aerodynamic shape and surface, manufacturing aspects, passenger comfort, integration of systems, crash performance, load transmission and suspension, transportation of the structure

Question 5

requirements of space structures

Answer 5

small thermal expansion, sufficient stiffness, interactions with attitude control, prevention of micro-vibrations, low weight, low cost, materials compatible with space (radiation, temperature), deployable components, limited payload space of launch vehicles, difficult maintainance aspect

Question 6

aircraft structural components

Answer 6

wing, fuselage, empennage (vertical tailplane (VTP), horizontal tailplane (HTP))

Question 7

the most load carrying component in an aircraft

Answer 7

skin

Question 8

primary structure of a wing

Answer 8

centre wingbox (inside fuselage)

wingbox: spars, ribs, skin

Question 9

primary structure of a fuselage

Answer 9

longeron, skin, frames, stringers

crash box, floor beam, pax (passenger) floor beam, floor beam strut

Question 10

load-carrying component of the fuselage during crash

Answer 10

pax (passenger) floor beams

Question 11

primary structure of a space launcher

Answer 11

from the top (example of Orion vehicle):
1. launch abort system
2. crew module
3. service module
4. encapsulated module panels
5. spacecraft adapter
6. Orion stage adapter
7. interim cryogenic propulsion stage
8. launch vehicle stage adapter
9. ring adapter
10. core stage
11. solid rocket boosters
12. engine

Question 12

primary structure of a satellite

Answer 12

monocoque frames, sandwich panels made of CFRP (with honeycomb core and adhesive layer)