Papers by Author: George Jeronimidis

Abstract: The paper presents results of a partial experimental programme carried out within the project EUREKA E! 2462 TRUS, which aim is to demonstrate a novel form of hybrid electric drive line without the need for overhead lines. The zero emissions public transport vehicle is based on a hybrid electric drive line with novel, strongly innovative features. The concept includes the use of a small on-board energy storage unit (flywheel) to store the energy that would otherwise be lost on braking. Results of an experimental complex programme of an evaluation of static mechanical and fatigue properties of long glass-fibre reinforced polyester composite material with biaxial or multiaxial structures, respectively, to be used for a manufacture of the flywheel hub disc are presented in the paper. It was shown that results of interlaminar shear fatigue strength of the disc mostly almost correspond to those obtained on basic material – biaxial GRP plates and are close to results obtained on a similar uniaxial GRP used for railways springs. Some ascertained differences are discussed.

Abstract: This paper shows the process of the virtual production development of the mechanical connection between the top leaf of a dual composite leaf spring system to a shackle using finite element methods. The commercial FEA package MSC/MARC has been used for the analysis. In the original design the joint was based on a closed eye-end. Full scale testing results showed that this configuration achieved the vertical proof load of 150 kN and 1 million cycles of fatigue load. However, a problem with delamination occurred at the interface between the fibres going around the eye and the main leaf body. To overcome this problem, a second design was tried using transverse bandages of woven glass fibre reinforced tape to wrap the section that is prone to delaminate. In this case, the maximum interlaminar shear stress was reduced by a certain amount but it was still higher than the material’s shear strength. Based on the fact that, even with delamination, the top leaf spring still sustained the maximum static and fatigue loads required, the third design was proposed with an open eye-end, eliminating altogether the interface where the maximum shear stress occurs. The maximum shear stress predicted by FEA is reduced significantly and a safety factor of around 2 has been obtained. Thus, a successful and safe design has been achieved.