Accession Number : ADP003110

Title :   On Crack Paths,


Personal Author(s) : Broberg,K. B.

Report Date : OCT 1983

Pagination or Media Count : 16

Abstract : In general the direction of crack propagation depends upon the propagation velocity, the ambient stress state (including its time variation), and the processes in the process region. In several cases the propagation velocity plays an insignificant role. These cases include certain fractures of thin plates at which the crack direction is outlined as a band of necking already before start of unstable crack growth. They also include certain fractures at plane strain, when the crack directions is obvious but still of minor interest. These cases include stability questions of the type: 'Is the straight path stable or not?' Then the answer 'yes' or 'no' is of primary interest, not the precise path at deviation from the straight line, which, moreover, generally depends upon the initial disturbance. In such cases a static analysis ought to be sufficiently informative. Even though branching in rare cases might appear at slow crack growth it is generally closely connected with rapid crack propagation. Thus the dynamic character of the phenomenon must be taken under consideration. (Author)

Descriptors :   *Aluminum, *Plates, *Cracks, *Crack propagation, *Paths, Orientation(Direction), Fracture(Mechanics), Stress concentration, Dynamic loads, Static tests, Velocity, Equations, Finite element analysis, Stability, Microstructure, Front ends and surfaces, Shear stresses, Fatigue

Distribution Statement : APPROVED FOR PUBLIC RELEASE