LIFE ESTIMATION OF A COMPOSITE STRUCTURAL COMPONENT IN A MULTI-AXIAL STRESS STATE

Aim of this work is to test and understand the mechanical behaviour, in multi-axial stress condition, of a composite material used to build a structural component, a corner beam of bus cabin. The bus cabin design is part of the European project Litebus, whose aim is the design of a module of a lightweight coach. A series of experimental tests was performed on specimens cut out from this beam. Different fibers orientation with respect to the direction of load application were considered: longitudinal (0°), normal (90°), inclined at 30° and 45°. The static and fatigue characterization were carried out to identify the mechanical behaviour in terms of S-N curves. Obtained fatigue data are then interpolated by fitting parameters required for multi-axial models of fatigue life estimation.