Failure mode transition in unidirectional E-glass/vinylester composites under multiaxial compression

Results from an experimental investigation on the mechanical behavior of a unidirectional fiber reinforced composite with 50% volume fraction E-glass/ vinylester and the vinylester matrix under uniaxial and proportional multia xial compression are presented. The stress-strain curve and the acoustic em ission records together with the post-mortem observations on the specimen s how the failure mode transition from axial splitting to kink band formation as the loading condition changes from uniaxial to proportional multiaxial compression. Axial splitting and "splitting induced" kink band formation we re observed in the uniaxially loaded specimen and the multiaxially loaded s pecimen showed conjugate kink bands and no axial splitting.