Fatigue Crack Propagation Analysis and Characterization Of Surface Cracks In Structural Steel Plates and Welded Joints

LEANDRO JAUREGUIZAHAR; MIRCO DANIEL CHAPETTI

Foz do Iguacu, Brazil

Congreso; 11th Pan-American Congress of Applied Mechanics (PACAM XI); 2010

San Carlos School of Engineering, Department Of Structural Engineering, University of San Pablo

This work is concerned with the analysis and characterization of the fatigue crack propagation of surface cracks in structural unwelded and welded steel plates. This analysis is done by using a dedicated experimental methodology that allows the detection and monitoring of the development of surface cracks by using a multi-strain gauges technique. Cracks are nucleated and propagated by fatigue from a small elliptical surface notch machined in the plate samples, or naturally nucleated from the toe of butt welded joints of the same plates. The methodology allows to characterize the fatigue crack propagation in the thickness directions of the plates and to obtain the corresponding material parameters of the Paris law. Then results allow to analyze and to compare the fatigue crack propagation from butt welded joints. The influence of different mechanical and geometrical parameters on the fatigue behavior of welded joint, as load ratio, thickness plate, reinforcement angle, etc., can be then study. Some preliminary results are presented for unwelded and welded ½ inch A36 steel plates