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Mixed‐mode crack opening displacement measurements for small fatigue cracks growing in Astroloy at 20 °C
Author(s) -
* Davidson
Publication year - 2000
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.1460-2695.2000.00293.x
Subject(s) - materials science , stress intensity factor , composite material , crack closure , displacement (psychology) , crack tip opening displacement , stress concentration , structural engineering , mode (computer interface) , stress (linguistics) , fatigue testing , mixed mode , fracture mechanics , engineering , psychology , linguistics , philosophy , computer science , psychotherapist , operating system
Crack opening displacements were measured for small fatigue cracks in Astroloy being grown with uniaxial stress application under high‐cycle fatigue conditions. Four cracks were investigated including one that grew from 27 to 74 μm in three increments. Most of the cracks grew at an angle to the loading axis and all opened bimodally. Crack opening scaled with distance from the crack tip similar to an elastic crack, which allowed the calculation of a local stress intensity factor for both mode I and mode II. The proportion of mode II stress intensity factor was relatively large, varying as 0.06 < Δ K II /Δ K I < 0.42, with an average of ~0.3. Thus, uniaxial loading remote to the cracks resulted in a bimodal opening response on the scale of the cracks.