Research on fatigue cracks in composite dowel shear connection

Last year, extensive research was conducted on a modern type of continuous shear connectors – the composite dowel PreCo-Beam (2001) [1] and innovative composite constructions were designed and built. As this shear connection is to be applied mainly for bridges, problems concerning fatigue behavior arise Berthellemy et al. (2009) [2]. Complicated stress distribution from external loads in steel dowels combined with different manufacturing technologies and resulting eigenstresses make the stress patterns in steel dowels very complex, and the problem of fatigue cracks even more complicated. This study presents investigations undertaken after completion of the PreCo-Beam project [1], which is a part of research to be conducted years 2009–2011 at Wrocław University of Technology. l information on an approach to estimating the fatigue resistance of composite dowels is presented, focusing on a description of stress analysis in steel dowels, and the impact of the manufacturing method on fatigue lifespan. The background to a detailed fatigue numerical analysis is presented, as are the initial results obtained from numerical simulations. These are verified against the background of experimental tests results.