To simplify construction, reduce weight and improve mechanical properties, a sandwich panel substitution process is performed on corrugated sheets in the floor and roof of a rail vehicle car body. A requirement based selection is used to design the sandwich panels with the corrugated sheet mechanical characteristics as boundaries. Car body stiffness is evaluated by modal analysis. The derived panels reduce the mass of the car body by 600-700kg. Results show the varying importance of the longitudinal, transverse and shear properties of the floor and roof panels, as well as how efficient the corrugated sheets actually are.

This paper investigates how various requirements, such as stiffness, strength, buckling, thickness and area density, influence the choice of load carrying sandwich panels for highspeed rail vehicles. Requirements on the load carrying structure are defined where after various sandwich alternatives are chosen to match these requirements. The initial panels are optimised with the software package HyperWorks. Refined optimisation results are then studied by Finite Element Analysis. A total weight reduction of over 30% of the load carrying structure is achieved.

This paper highlights one of the main issues with light weight sandwich design in high-speed rail vehicles: The benefit of light weighting is said to be marginal when considering high-speed trains. A run cycle based analysis method is used to evaluate energy savings, wear reduction, downsizing possibilities and reduced travel time as function of reduced weight. Depending on operating conditions, the relation between weight reduction and energy consumption for high-speed trains is shown to be equivalent of that for both automobiles and aircrafts.

The finite difference method is used to solve the time-dependent thermo mechanical response of a layered composite structure subjected to fire. State variables of the composite are chosen whereby the external and internal boundary conditions are derived for an irregular grid through the thickness of the structure. The homogenised mass flux and specific heat capacity of pyrolysis gases over a layered composite is also defined. The formulations are tested against documented results found in the literature.

A multi-level, multi-functional, optimisation methodology is suggested for the design of a composite high speed train car body. The structure consists of a layer of inner lining (glass fibre/vinyl ester), a layer of fibrous insulation, and a load carrying sandwich panel (carbon fibre/epoxy face sheets on a PMI core). Besides the most commonly used design constraints, such as mechanical strength, stiffness and geometry, also acoustic and thermal insulation as well as fire safety is included in the optimisation. The results suggest that well over 40 % mass reduction can be achieved with these types of structures.