Mechanical design and construction of machines


The purpose of the research proposased in the field of mechanical design and mechanical engineering is the study of stress and the response of materials used in innovative systems of turbines integrated with electric generators to ensure reliability levels suitable to the respective applications. The main phenomena to investigate are the issues concerning multi-axial fatigue, dynamics and stability of rotors, the mechanical behavior of joints, the fretting fatigue in the mechanical components in contact. 

Multiaxial fatigue phenomena 

The mechanical components used in the production of rotor and stator parts mechanical and electrical integrated, are subject to complex load histories, able to determine multi-axial stress variables whose effects must be studied case by case In particular it is necessary to define numerical and experimental analysis of the history of the stress, to test the applicability of multi-axial fatigue criteria, to carry out any tests to characterize and determine the parameters of multi-axial fatigue of the materials used 

Dynamics and stability of rotors 

In particular applications the rotors are affected by variable forces generated by permanent magnets. They should therefore be detailed dynamic behavior of rotors, the conditions of resonance and stability fields of speeds through the development of appropriate forecast models and techniques of experimental verification 

Mechanical behavior of joints 

In the joint areas of the mechanical components stress concentration effects appear and, in the case of welded joints, the change in the characteristics of the materials can produce substantial reductions in the reliability of components. The mechanical behavior of the specific joints used must be appropriately modeled and analyzed. Also be investigated phenomena related to the factors of notch effect and enforceability of the verification techniques of hot-spots 

Fretting fatigue 

Fretting fatigue arises at the bodies kept in contact and are encouraged by variables forces. In some conditions the fretting can lead to a drastic reduction in fatigue life reliability of mechanical components. In the rotors, where forcings and fixings are used, fretting can take a significant effect in the presence of vibration. The experiences developed in the field of contact mechanics and parameters suitable to characterize the intensity of the phenomena of fretting will be used for prediction and verification of fretting phenomena in components designed for the construction of turbines integrated with generators