Fatigue and Stress | Design Philosophy Flashcards
This will determine the __- of an airframe
life
The fatigue life of a fuselage is based on ___ ___
pressurisation cycles
Repetitive pressurisation cycles can induce ___ ___, which can cause fatigue cracks
hoop stresses
Greater mass means ___ structural loads
greater
A change in one unit of the load factor means a _% change in the weight of the aircraft
1
The relationship between the Design Limit Load and the Design Ultimate Load is the __ ___ ___
factor of safety
The Design Limit Load refers to the ___
maximum load value of the repeated stress during normal operations
The Design Ultimate Load is the Design Limit Load increased by a safety factor of __%
50%
___ failures are caused by weak components that are either badly made or not inspected properly
Infant
Hard Time Maintenance is used when ___
the known deterioration of an item is limited to an acceptable level by maintenance at certain time periods
On-condition Maintenance is a preventative process in ___
which an item is monitored continuously or at specified periods, without disassmebly
Having a Mean Time to Failure of 3000 hours means that there is a ___ certainty of it surviving its normal life without failure
99.9
Fail safe means that no one part of a system takes the complete load, meaning that there are ___ and ___ paths
parallel structural
Spars my have ___, acting as fail-safes.
doubles
___ tolerance accepts that production flaws might exist and they are detected and fixed before they become critical
Damage
