Fatigue reliability analysis of steel bridge details based on field-monitored data and linear elastic fracture mechanics

Increasing use of ceramics in structural applications has led to the development of a probabilistic design methodology that combines three elements: linear elastic fracture mechanics theory that relates strengths of ceramics to size, shape, and orientation of critical flaws, a characteristic flaw size distribution function that accounts for the size effect on strength via the weakest-link concept, and a time-dependent strength caused by subcritical crack growth or other mechanisms. This paper reviews recent research that has been focused on the first of the above three elements, the investigation of fracture criteria for arbitrarily oriented flaws in ceramics, i.e., the mixed-mode fracture problem in linear elastic fracture mechanics theory. Experimental results obtained with two-dimensional through cracks and three-dimensional surface (indentation) cracks are summarized and compared to mixed-mode fracture criteria. The effects of material microstructure and the stress state on mixed-mode fractures are discussed. The application of mixed-mode fracture criteria in reliability analysis is illustrated for several simple stress states in the absence of time-dependent strength degradation.

Download Full-text

Application of statistical linear elastic fracture mechanics to pressure vessel reliability analysis

Nuclear Engineering and Design ◽

10.1016/0029-5493(74)90184-8 ◽

1974 ◽

Vol 27 (3) ◽

pp. 413-425 ◽

Cited By ~ 27

Author(s):

P.E. Becher ◽

A. Pedersen

Keyword(s):

Fracture Mechanics ◽

Reliability Analysis ◽

Pressure Vessel ◽

Linear Elastic Fracture Mechanics ◽

Linear Elastic ◽

Elastic Fracture

Download Full-text

Fatigue Evaluation of Steel Bridge Details Integrating Multi-Scale Dynamic Analysis of Coupled Train-Track-Bridge System and Fracture Mechanics

Applied Sciences ◽

10.3390/app10093261 ◽

2020 ◽

Vol 10 (9) ◽

pp. 3261 ◽

Cited By ~ 3

Author(s):

Huile Li ◽

Gang Wu

Keyword(s):

Fracture Mechanics ◽

Dynamic Analysis ◽

Linear Elastic Fracture Mechanics ◽

Steel Bridge ◽

Train Track ◽

Linear Elastic ◽

Multi Scale ◽

Elastic Fracture ◽

Fatigue Evaluation ◽

Track Bridge

Increased running speed and axle weight in the transportation network lead to significant dynamic interactions between the vehicles and bridges. It is essential to capture these interactions in fatigue analysis of steel bridges. This paper presents a framework for fatigue evaluation of critical steel bridge details through multi-scale dynamic analysis of the train-track-bridge system and linear elastic fracture mechanics. The multi-scale coupled dynamic analysis allows accurate and efficient computation of fatigue stresses produced by the moving trains in structural details based on a vehicle-bridge analysis model composed of a 3D vehicle model, multi-scale bridge finite element model including the track system, and a wheel–rail interaction model. Field data from an existing steel-truss railway bridge are used to validate the multi-scale analysis method. Enhanced fatigue evaluation of the bridge detail is performed using the computed fatigue load effects and linear elastic fracture mechanics. The effects of the track irregularity and operating train speed on fatigue crack propagation life are investigated. The presented framework is general and can be applied to other types of steel bridges such as the steel-box girder bridge with orthotropic decks.

Download Full-text