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ISO 11439 standards consider 4 types of high-pressure cylinders to storing natural gas for vehicles applications. Among them the type 2, metal-lined hoop wrapped cylinder, is the aim of this work. It describes a numerical model built using ANSYS application to determine stress on the metal liner and on composite material applied on the liner by filament winding process. Using design criterion for laminate composites, the total thickness of the composite layer has been evaluated to get an optimized value. Employing the element shell multilayer of ANSYS 8.1 and a model of the type 2 cylinder, the stress state in the metal liner and in each layer of the composite has been studied.

Brake drums are components designed to dissipate kinetic energy of vehicles, converting it, mostly, into thermal energy. The stress state originated by thermal transients produced by braking cycles may nucleate fatigue cracks and lead the component to failure. The aim of this work is to analyze and compare thermal fatigue strength for brake drums, made in vermicular cast iron, with different design geometry. Firstly, fatigue life has been evaluated for the original geometry. The same analysis has been performed after reducing the thickness of the brake drum. From thermal and structural analisys, via finite element method, temperature evolution and loading history for the component have been obtained. The life of the component has been estimated for the region with the highest probability for crack nucleation by thermal fatigue. The rain-flow method of counting cycles has been applied and Goodman equation has been used to evaluate the fatigue life of the component.