Determination of the critical fatigue crack length for orthotropic steel decks

Due to the difficulty in determining damage tolerance, orthotropic steel decks (OSD) lack a uniform failure judgment criterion, leading to various fatigue damage evaluation results. One fatigue damage tolerance determination method was proposed based on critical crack length (CCL), which is calculated by log-linear unary functions. Both fatigue tests and numerical simulations were conducted to verify this method. The results indicate stress intensity factor at critical cracks is mainly controlled by the crack length. CCL is affected by stress magnitude and boundary size with a quantitative conversion relationship, and the conversion formulae were established with errors within 15%. The proposed method could reasonably predict CCL with an average error of around 10%. Compared with IIW, this method showed superior applicability in the failure judgment of OSD welded joints. [Display omitted] •Rapidly determine critical crack length without complicated finite element analysis.•Calculate the SIF of the critical crack by log-linear unary functions.•Proposed damage tolerance determination method showed tiny errors.•Assess the applicability of common failure criteria to orthotropic steel decks.