铁路正交异性钢桥面板典型疲劳裂纹寿命估算

ypical fatigue cracks observed in the orthotropic steel decks of railway bridges due to high concentrated stress are investigated. The stress variations of the main weld connections, under railway loading, are analyzed using the finite element method. The least favorable locations of the typical fatigue cracks are determined based on the stress analysis in conjunction of a global model and sub-structural fine model. Stress concentration is found sensitive to the detail of welded joints. Sub-structural models are developed using plane strain or solid elements in the typical fatigue areas. The stress distributions perpendicular to the cracks are analyzed along the crack growth direction. Based on the FE results, fatigue life of the typical cracks are estimated by numerical integration of Paris law in terms of the liner elastic fracture mechanics.