China
Africa
Explore chapters and articles related to this topic
Fracture Mechanics
Published in Cameron Coates, Valmiki Sooklal, Modern Applied Fracture Mechanics, 2022
Cameron Coates, Valmiki Sooklal
The Aloha Airlines 1988 accident [6] involved the total separation of the upper aircraft skin and fuselage while in flight, which resulted in one fatality and eight serious injuries. This accident spurred advances in damage tolerant design methods, particularly in the case of multiple site damage in aircraft structures. “Damage tolerance” refers to the ability of structural components to perform despite containing cracks that may or may not be growing.
Aviation Safety in an International Environment
Published in Hans M. Soekkha, Aviation Safety, 2020
The damage tolerance approach requires the probable locations and modes of cracking to be determined, the consideration of multiple defects, fatigue test evidence and substantiated inspections. All this only applied to new aircraft designs and as the rules were not retrospective, some way had to be found to cover the existing fail-safe designs.
Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
Damage tolerance - A methodology that seeks to prevent catastrophic failures in components that experience time-dependent cracking. Fracture mechanics analyses are used in conjunction with nondestructive examination (NDE) to ensure that any flaws that may be present will not grow to a critical size prior to the next inspection.
Material parametric optimisation of wing leading edge profile against soft body impact
Published in International Journal of Crashworthiness, 2022
Bird strike is a serious and damaging event; hence it must be accounted for in the design of flight-critical aircraft components. Airworthy regulatory authorities like FAA and EASA have defined bird strike regulations for civil aircraft that come under FAR 25 or CS 25 clauses. The certification requirements for the leading edges of the wing for the aircraft are standing on regulations FAR 25.571 under FAA (FAA 2017) [5]. FAR Part Section 25.571 (Damage – tolerance and fatigue evaluation of structure) mentioned that the airplane must be able to successfully complete a flight in case any structural damage takes place as a result of impact with a 4-pound bird when the velocity of the airplane relative to the bird along the flight path of the airplane is equal to VC at sea level or 0.85 VC at 8000 ft, whichever is more critical. The damaged structure must capable to bear the static loads (ultimate loads) which are fairly anticipated to occur on the flight. Dynamic effects on these static loads need not be considered. If significant changes in structural stiffness or geometry, or both, follow from structural failure or partial failure, the effect on damage tolerance must be further investigated. [5,6]
Mode-III stress intensity factors for two circular inclusions subject to a remote uniform shear load
Published in Journal of the Chinese Institute of Engineers, 2018
Ching-Kong Chao, S.C. Tseng, F.M. Chen
Composite materials are widely used in modern engineering applications such as thermal barrier coatings and electronic packages. Due to the rapidly increasing use of high-quality composite materials in advanced engineering structures, the damage tolerance and reliability of composite structures have become matters of serious concern. There arose the problem of finding stress distribution in composite materials or structures containing imperfections in the form of cracks. It is essential to have a full understanding of the stress field near the crack tip such that crack propagation in a cracked composite can be predicted precisely. The stress intensity factors (SIFs) introduced by Irwin (1957) have been applied to analyze the problem in the framework of linear fracture mechanics.