Table of Contents
- 1 What is fatigue and damage tolerance?
- 2 What is damage tolerance in aviation?
- 3 What is damage tolerance concept?
- 4 When should fatigue analysis be done?
- 5 What does tolerance mean in aircraft?
- 6 What is damage tolerance inspection?
- 7 What are the stages of fatigue failure?
- 8 What is fail safe design and why does it matter?
- 9 What is fatigue loads and spectra?
- 10 What are the three main subjects of fatigue analysis?
What is fatigue and damage tolerance?
Fatigue and Damage Tolerance is a specialized discipline involving the assessment of the response of materials and structures to the aircraft and propulsion system mission cycles, most notably cyclic loading (i.e., the application of repeated or fluctuating stresses, strains, and stress intensities).
What is damage tolerance in aviation?
Damage tolerance is the ability of an aircraft structure to sustain damage, without catastrophic failure, until such time that the component can be repaired or replaced.
What are the three main aspects of damage tolerance?
Damage tolerance analysis stresses in the structure (both fatigue and operational maximum stresses) that cause crack growth from the damaged condition. geometry of the material which intensifies or reduces the stresses on the crack tip.
What is damage tolerance concept?
Damage tolerance is the ability of structures to withstand the design load and maintain their function in the presence of cracks and other types of damage.
When should fatigue analysis be done?
Fatigue analysis is performed to find out the satisfactory performance level of a structural member under cyclic loading. Means fatigue analysis will give data related to crack initiation, crack propagation, and finally failure probability for a specific material.
What is fatigue lifetime?
Fatigue life is a mechanical and scientific term that relates to how long an object or material will last before completely failing because of concentrated stresses. In most cases, fatigue life is calculated as the number of stress cycles that an object or material can handle before the failure.
What does tolerance mean in aircraft?
Tolerance. The sum of the plus and minus allowance figures. source: FAA Aviation Maintenance Technician General Handbook (FAA-H-8083-30) the range of values within which a system can operate correctly: The A.C. power supply has a tolerance of +/- 2 volts.
What is damage tolerance inspection?
Definition. Damage tolerance, or safety by inspection, was developed as a design philosophy in the 1970s as an improvement on the fail-safe principle for structural deterioration. A key element is the development of a comprehensive programme of inspections to detect cracks before they can affect flight safety.
Why fatigue is a problem?
Fatigue can be caused by a number of factors working in combination, such as medical conditions, unhealthy lifestyle choices, workplace problems and stress. Fatigue is a known risk factor in motor vehicle and workplace accidents. Always see your doctor for diagnosis if you are suffering from chronic tiredness.
What are the stages of fatigue failure?
There are three stages of fatigue fracture: initiation, propagation, and final rupture.
What is fail safe design and why does it matter?
Fail-safe designs are designs that incorporate various techniques to mitigate losses due to system or component failures. The design assumption is that failure will eventually occur but when it does the device, system or process will fail in a safe manner.
What is fatigue damage accumulation and non-destructive inspection?
Fatigue Damage Accumulation: crack growth, residual strength and failure analysis, fail safety, damage tolerance, safe life, inspections. Introduction to Non-destructive Inspection: inspection techniques, probability and reliability of inspections, inspection limitations.
What is fatigue loads and spectra?
Fatigue Loads and Spectra: load spectra, variable amplitude loading in fatigue, variable amplitude loading in crack growth, effects of load history. Fatigue and Failure of Joints and Structure: fastened structures and stiffened structures.
What are the three main subjects of fatigue analysis?
Subjects include the following: evolution of requirements for preventing fatigue damage, fatigue mechanism, stress concentrations, fatigue properties, fatigue strength, damage accumulation, stress intensity factor, crack growth, residual strength plus failure criterion, constant and variable amplitude loading, load spectra, inspection techniques.