Fatigue behaviour of materials and components has been one of the main research topics in the last decades. Several studies have been carried out in collaboration with industries (Fiat, Agip, Piaggio, Nuovo Pignone, Tecnomare, Magneti Marelli, etc.) and national and international agencies (ENEA, ENEL, ANPA, IAEA, etc). Some experimental activities have been performed by means of the available electro-hydraulic testing machines, for other tests, non-standard innovative procedures and facilities have been designed and set up. Fatigue tests are performed by means of Computer Aided Testing procedures and metallographic and microscopic (optical or SEM) analyses are applied for characterising the failure surfaces.
High temperature low cycle fatigue tests have been conducted on stainless steels and the creep-fatigue interaction investigated. The fatigue crack growth phenomenon has been extensively studied both from the experimental and theoretical-computational viewpoint. Fatigue crack growth resistance of high strength steels employed in the off-shore technology have been characterised in the sea-water simulated environment in electrochemical controlled conditions. Methods for interpreting and predicting fatigue crack growth in residual stress fields typical of welded structures have been proposed and experimentally verified. Ultrasonic non-destructive examination procedures have been applied to detect the fatigue delamination growth in composite laminates.
Many research efforts have been devoted to assess the fatigue strength of mechanical structures and components. Components and assemblies have been tested in simulated operative conditions in order to investigate the influence of production and assembly technologies, particularly welding. In order to study the fatigue behaviour of conical threaded connections for drill pipes employed in oil extraction technology, special resonant testing machines have been designed and constructed. By an innovative controlling method, alternating bending loading at constant amplitude (up to 130 KNm) and constant frequency (up to 30 Hz) can be imposed during the whole test duration. By means of small changes in the gripping devices for securing the specimens, different shapes can be tested (for instance large shafts of trucks or busses) and alternating torque could be applied.

Contact person
Prof. L. Bertini E-mail This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Dr. Ing. Ciro Santus E-mail This e-mail address is being protected from spambots. You need JavaScript enabled to view it