Alternative Design of Steel/Aluminium Car Deck Panels

Abstract

This thesis evaluates if parts of the structural elements in a liftable car deck can be replaced with aluminium to obtain a lower weight. In order to be able to compare the final solution to an existing one, two car deck panels with different dimensions(14.37x14.64 and 14.37x10.22) on a Pure Car and Truck Carrier (PCTC) were used as a reference. Different concept designs where the steel top plate was replaced by an aluminium structure were evaluated by utilizing engineering beam theory, goal driven optimization and finite element analysis. The evaluation resulted in a steel/aluminium car deck design with extruded aluminium profiles as a stiffened top plate and a conventional steel beam system structure as support. The final design of the larger car deck panel resulted in a weight reduction of 7.5% while the smaller car deck panel was weight reduced with 28.7%. Based on this difference, studies of how the free length between supports affects the steel structural weight were carried out. A cost analysis was performed to evaluate whether the design was economically feasible. It was found that the payback time of the proposed design is 2.4 times the desired payback time, compared to the average life time of a PCTC which is 23 years, it was concluded that with the aluminium cost of 2014 the design is too expensive.