Articles of The Transactions of KSRC

Stress-life criteria for fatigue assessment of struc-tures: problems of implementation

Full text article ( in russian)

Year	2018
Issue	20182
Volume	2
Pages	96-103
Caption	Stress-life criteria for fatigue assessment of struc-tures: problems of implementation
Authors	Petinov S.V., Guchinsky R.V.
Keywords	fatigue life, criteria for fatigue, fatigue assessment methods, fatigue damage accumulation, uncertainties in fatigue analyses
DOI	10.24937/2542-2324-2018-2-S-I-96-103
Summary	Presently in rules for fatigue assessment of steel, and in particular, welded structures in different technologies subjected to intensive alternating service loading the Stress-Life (S-N) criteria are recommended in several versions of approaches. These are the Nominal stress approach based on typifying welded joints and representing fatigue resistance of the joints by classed S-N curves; the Hot-spot stress approach focused on evaluation of «structural» stress and the Notch-stress approach based on the FEA-based assessment of the local stress caused by the geometry of structural detail and the weld shape. The criteria and approaches provide assessment of fatigue properties of structures, however, accompanied with a series of approximations and uncertainties. A more consistent in sense of physics and mechanics of the damage evaluation of fatigue life may be provided by the strain-life or inelastic strain energy based approaches, again, coupled with uncertainties. The nature of drawbacks of the S-N criteria and approaches is commented and feasible means of improvement the fatigue criteria evaluation and applications in fatigue assessment procedures are proposed.