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A nonlinear continuous damage model based on short‐crack concept under variable amplitude loading
Author(s) -
Zhang J.,
Yang S.,
Lin J.
Publication year - 2016
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 - 10.1111/ffe.12334
Subject(s) - nonlinear system , structural engineering , materials science , amplitude , variable (mathematics) , stress (linguistics) , paris' law , crack closure , mechanics , fracture mechanics , composite material , engineering , mathematics , mathematical analysis , physics , linguistics , philosophy , quantum mechanics
In this paper, a modified nonlinear damage accumulation model is proposed by using intrinsic crack size as the damage variable in the stress‐control condition. The model's development is based on the Chaboche nonlinear damage law and the short‐crack theory. The validations are confirmed by using the experimental data of Ti–6Al–4V and 2024‐T3 collected from tests and literature. The model capabilities of predicting damage accumulation and crack growth rate in the multi‐level loading condition as well as the variable amplitude loading condition with single and multiple over‐load are investigated and discussed in detail. Comparison results show that the proposed model is able to consider the loading ratio, the loading sequence and the over‐load effect on damage accumulation correctly. Meanwhile, the damage accumulation in the last stage of fatigue life can be described more clearly by the proposed model attributed to the use of crack size as the damage variable.