Evaluation Index System for Identifying High-Risk Fracture-Prone Areas of Ship to Shore Gantry Crane

This study focuses on the compound risks throughout the entire life cycle of ship to shore gantry cranes. Additionally, it constructs a high-risk fracture-prone area evaluation system that covers the four stages of design, manufacturing, service, and maintenance. Guided by the evolution mechanism of structural fatigue cracks, six typical stress concentration areas on the main girder, drag rods and gantry of ship to shore gantry cranes are selected as evaluation points. Quantitative indexes are obtained through the fusion of finite element simulation and measured data. The qualitative indexes are quantified by a five-level language scale combined with triangular fuzzy numbers. The weight distribution introduces the game theory combination mechanism, and the optimal combination coefficient is solved through the Least Square Method. Subjective weighting is carried out through the Analytic Hierarchy Process(AHP), and objective weighting is conducted through the Coefficient of Variation Method(CV) and the Entropy Weight Method(EWM), achieving the integration of subjective and objective weighting. The indexes evaluation adopts the Grey Relational Degree -TOPSIS composite model(GRA-TOPSIS). By comparing the ranking results of the combined weight method and the single EWM proposed in this paper through numerical examples, it can be seen that the combined weight method is superior. And it is verified that the index evaluation system is applicable to the identification of high-risk fracture-prone areas of ship-to-shore gantry cranes.