Multi-Axial Fatigue Life Prediction of a Composite Structural Component

Aim of this work is to test and understand the mechanical behavior of a composite material used to build a structural component, in particular a corner beam of a bus cabin. This component is obtained by means of the pultrusion technique and presents random and longitudinal E-glass fibers as reinforce, while the matrix is a vinyl-ester resin. 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°) and inclined (45°), thus both in uni-axial and multi-axial loading conditions. A static and fatigue characterization was carried out to identify the mechanical behaviors and the failure modes in these directions. Obtained fatigue data are then interpolated by fitting parameters required for models of fatigue life prediction.