Foto del docente

Dario Croccolo

Professor

Department of Industrial Engineering

Academic discipline: ING-IND/14 Mechanical Design and Machine Construction

Head of Interdepartmental Centre for Industrial Research in Advanced Mechanical Engineering Applications and Materials Technology

Research

Study and design of motorbike mechanical components. The investigations have been particularly focused on the shaft-hub couplings between the fork and the steering pin of front suspensions. This type of couplings is realised as a compression-fit one in which one of the components (the fork) is not symmetrical in shape.

Study of adhesively bonded and press fit couplings.

Fatigue behaviour and endurance limit study for shaft-hub couplings.

Analysis of some critical aspects regarding bolted connections and clamped joints have been studied in order to define the tribological behaviour of contact surfaces with the aim of evaluating and defining the coefficients of friction, the forces and the torque moments useful for the correct exploitation of the joints.



His basic and applied research activities concern the study and the design of motorbike mechanical components. The investigations have been particularly focused on the shaft-hub couplings between the fork and the steering pin of front suspensions. This type of couplings is realised as a compression-fit one in which one of the components (the fork) is not symmetrical in shape. The research activities were dedicated to developing a new mathematical model useful to perform the calculation of the push-out force. The starting point was to try to correct Lamè's well-known formulae valid for high thickness pipes in the elastic and the symmetric field. These formulae were corrected adding some appropriate coefficients, which are able to take into account the different circumferential stiffnesses of the forks and, thus, to compute more accurately the tensile state produced close to the coupling surfaces with errors lower than 10%. All the findings were obtained using a hybrid method that consists in the execution of a large number of FEM analyses to be compared with the results coming from the theoretical and experimental results. Another problem investigated and strongly connected with the shaft-hub couplings, is the definition of fatigue limit of the components and the determination of the stress concentration factors of these couplings.

A large amount of effort has been dedicated to the study of adhesively bonded and compression fit couplings. The combined effects of this type of joining techniques, have been extensively studied in order to evaluate their influence on the failure load of the couplings; the failure load has been evaluated on the basis of a large number of parameters by applying the Design of Experiment method. In this type of couplings the interference level was evaluated according to the theoretical formula described above and performing some FEM analyses. Finally the defect density of the adhesive was evaluated by applying the acoustic emission technique as non-destructive testing method.

In recent years, some critical aspects regarding bolted connections and clamped joints have been studied in order to define the tribological behaviour of contact surfaces with the aim of evaluating and defining the coefficients of friction, the forces and the torque moments useful for the correct exploitation of the joints.

The research has been carried out in cooperation with some important companies which supported the activities with specific agreements or Doctorate scholarship grants drawn up with the DIN Department of the University of Bologna; the research results are presented in the papers reported in the publications list of one of the next sections.

Latest news

At the moment no news are available.