Aircraft Structural Integrity and Fatigue Life Management Flashcards
What is the probability of a structural failure during an aircrafts planned life?
1/1000
What is stress?
When a load is applied to a solid, a stress is produced, measured as the load divided by the cross-sectional area.
What are the 4 types of stress?
Compression (Pushing)
Tension (Pulling)
Torsion (Twisting)
Shearing (2 Metals moving over each other)
What is ultimate stress?
The stress at which a structure or material will fracture, and fail is known as ‘Ultimate Stress’
What are the stages of Fractures occurring?
Crack Initiation, Crack Growth and Final Fracture.
What is Critical Crack Length?
Critical Crack Length (CCL) is the length at which a crack propagates catastrophically to failure.
What is the S-N curve?
The relationship between applied alternating stress levels and the endurance to failure of a material can be illustrated in an ‘S-N Curve’. This plots the applied percentage of ultimate stress against the number of cycles to failure.