STP687: Part-Through Crack Problems in Aircraft Structures

    Rudd, JL
    Aerospace engineer and supervisory aerospace engineer, Air Force Flight Dynamics Laboratory, Wright Patterson AFB, Ohio

    Hsu, TM
    Aircraft development engineer-specialist, Lockheed-Georgia Co., Marietta, Ga.

    Wood, HA
    Aerospace engineer and supervisory aerospace engineer, Air Force Flight Dynamics Laboratory, Wright Patterson AFB, Ohio

    Pages: 27    Published: Jan 1979


    Abstract

    Flaws occur in aircraft structures due to material and structural manufacturing and processing operations. The most prevalent sources of cracking in aircraft structures are fastener holes, although cracking does occur at locations other than fastener holes (for example, surface cracks). This paper presents a discussion of the most common types of flaws which exist in aircraft structures and the test data and analytical criteria needed to predict their growth. A number of special analytical and structural considerations are discussed such as small flaws, cold-worked holes, plasticity effects, failure criteria, and multiple flaw sites. The analytical crack growth and residual strength requirements which must be met as well as the initial flaw sizes and shapes which must be assumed in the Air Force damage tolerance design requirements (MIL-A-83444) are presented. Recently developed stress intensity factor solutions for quarter elliptical corner cracks emanating from various types of fastener holes are presented. Predictions using these current solutions are correlated with other approximate solutions as well as experimental test data.

    Keywords:

    part-through cracks, aircraft structure, damage tolerance, stress intensity factors, design criteria, fastener holes, crack propagation, fatigue (materials)


    Paper ID: STP35039S

    Committee/Subcommittee: E08.04

    DOI: 10.1520/STP35039S


    CrossRef ASTM International is a member of CrossRef.