The safety factor is the ratio of the component's ultimate load to its limit load.
Safety Factor = Ultimate Load / Limit Load
= 5.28 kN / 1.32 kN
= 4.
The safety factor of the aircraft component is 4.
Considering this safety factor, it seems more likely that the component was designed using a fail-safe philosophy. In the fail-safe design philosophy, components are designed to fail in a manner that is safe when they have exceeded their limit. A safety factor of 4 implies that the component can handle loads up to 4 times the limit load, which aligns with the fail-safe design philosophy. Safe-life philosophy, on the other hand, primarily aims to structure components so they won't fail within their intended lifespan or use, and may not necessarily cater for loads multiple times above their limits.
An aircraft component has an ultimate load of 5.28 kN and a limit load of 1.32 kN. What is its safety factor?
Based on this safety factor, do you think it was designed using a fail-safe philosophy or a safe-life philosophy?
3 answers
Safe-life philosophy
The safe-life philosophy designs components on the assumption they will not fail within their intended lifespan. This design philosophy is mainly used when failure could result in catastrophic consequences. The design ensures materials and construction will endure for their predicted life under predicted loads. There usually isn't a planned failure point, and the safety factor often involves taking into account material fatigue and other stressors that might occur during operation.
So, in the context of an aircraft component with a safety factor of 4, it's certainly still possible it was designed with a safe-life philosophy. The high safety factor ensures that the component can handle much more strain than it's likely to encounter in ordinary use, significantly lowering the chances of a catastrophic failure during its expected service life. Ultimately, the distinction between fail-safe and safe-life often isn't clear-cut and a particular design might incorporate principles from both philosophies.
So, in the context of an aircraft component with a safety factor of 4, it's certainly still possible it was designed with a safe-life philosophy. The high safety factor ensures that the component can handle much more strain than it's likely to encounter in ordinary use, significantly lowering the chances of a catastrophic failure during its expected service life. Ultimately, the distinction between fail-safe and safe-life often isn't clear-cut and a particular design might incorporate principles from both philosophies.
2 answers