A study on the role of powertrain system dynamics on vehicle driveability

Vehicle driveability describes the complex interactions between the driver and the vehicle, mainly related to longitudinal vibrations. Today, a relevant part of the driveability process optimisation is realised by means of track tests, which require a considerable effort due to the number of parameters (such as stiffness and damping components) affecting this behaviour. The drawback of this approach is that it is carried on at a stage when a design iteration becomes very expensive in terms of time and cost. The objective of this work is to propose a light and accurate tool to represent the relevant quantities involved in the driveability analysis, and to understand which are the main vehicle parameters that influence the torsional vibrations transmitted to the driver. Particular attention is devoted to the role of the tyre, the engine mount, the dual mass flywheel and their possible interactions. The presented nonlinear dynamic model has been validated in time and frequency domain and, through linearisation of its nonlinear components, allows to exploit modal and energy analysis. Objective indexes regarding the driving comfort are additionally considered in order to evaluate possible driveability improvements related to the sensitivity of powertrain parameters.     

Italian ports: towards a new governance?

The adoption in 1994 of the law n. 84 introducing the landlord port model marked the starting point of a prime period for the Italian port industry. It contributed to the national port industry renaissance: Italian ports became again the leaders in the Mediterranean basin, both as gateway ports and as transhipment ports. Looking back to its 15 years of enforcement, critical aspects and weaknesses have been observed. The incentive to reflect on the governance structure of ports and on the changes affecting the whole logistics transport chain is driven by the relative and absolute loss of position of Italian ports with respect to their competitors of the North as well as of the South European range (and the ports of Northern Africa which are expected to compete fiercely in the coming future). Considering only the container traffic, from 2003 to 2008 the market share of Italian ports decreased from 20.7% to 15.7% in favor of its main European competitors. The loss of attractiveness of Italian harbors is a clear symptom of the several difficulties national ports face in dealing with the rapid changes affecting the port industry. This paper discusses the bill presented by the Italian Government concerning the ports governance reform.