FATIGUE CRACKS AT RUNWAYS OF MONORAIL GIRDERS

Effects of Vertical Pre-Release Cracks on Prestressed Bridge Girders

The Discussion on Deflected Pre-Stressed Tendons and Diagonal Cracks of Webs in PSC Box Girders

In order to find the relationship between deflected pre-stressed tendons and diagonal cracks of webs and provide basis to design and construction of bridges, a characteristics section model of a long span pre-stressed concrete continuous box girder, which is now under construction in Chongqing is analyzed by using nonlinear finite element program Midas-FEA. A numerical simulation analysis to th...

Sonic Infrared Imaging of Fatigue Cracks

Quality Factor and Microslipping of Fatigue Cracks in Thin Plates at Resonant Vibration

Resonant vibrations have been stimulated in thin metal plates using a non-contacting electromagnetic driver. A sinusoidal force was applied in a swept frequency fashion and the resulting surface displacements were monitored through the use of an acoustic microphone. It has been found that the presence of a fatigue crack in the sample causes a broadening of the second resonance peak. The Q facto...

Modeling of fatigue crack closure in inclined and deflected cracks

A 2-dimensional, elastic-plastic finite element model has been developed to simulate plasticity induced crack closure in slanted and deflected cracks growing outside the small scale yielding (SSY) regime. The finite element model allows for contact between deformable surfaces to capture the complex contact interaction between the crack faces. Coulomb’s friction law has been used to model fricti...