Abstract
Referring to literature on crack analysis, flaw interaction criteria of existing codes i. e. WES 2805 mainly, are critically investigated. Those arguments are based on stress intensity factors in various situation of cracks. It is shown that PD 6493 and ASME code XI are more conservative than WES 2805 in many cases.
To verify existing codes, fracture tests are carried out by means of PMMA plate with two surface or through-thickness cracks. Comparing fracture stress in the case of two cracks with that of combined crack according to the codes, it is concluded that moderate sefety margin is set for most cases but excessive in some cases. Particularly WES rules for both-sided surface crack seem to be too conservative.
