Premium
MECHANICAL REASONS FOR PLASTICITY‐INDUCED CRACK CLOSURE UNDER PLANE STRAIN CONDITIONS
Author(s) -
Riemelmoser,
Pippan
Publication year - 1998
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1046/j.1460-2695.1998.00131.x
Subject(s) - crack closure , wedge (geometry) , plasticity , materials science , crack tip opening displacement , plane stress , mechanics , wake , crack growth resistance curve , fracture mechanics , closure (psychology) , structural engineering , composite material , geometry , finite element method , physics , mathematics , engineering , market economy , economics
A mechanical explanation of plasticity‐induced crack closure under plain strain conditions is given first by means of dislocation mechanics and then by the methods of continuum mechanics. In plane strain, the event of crack closure is due to transport of material from the wake to the crack tip. It is an elastic effect caused by the response of the matrix surrounding the plastic wake. The transported material produces a wedge which follows the crack tip, and unlike the plane stress condition it does not leave a remaining layer on the crack flanks. The length of the produced wedge at the crack tip is of the same scale as the plastic zone. It is then shown that in spite of its smallness this wedge is able to cause the experimentally observed shielding effect. The results also suggest that the discrepancies concerning the interpretation of fatigue crack growth and closure experiments are likely to be due to differences in accuracy in the detection of such small but nevertheless effective wedges.