MODELING OF DELAMINATION INFLUENCE ON MECHANICAL CHARACTERISTICS OF COMPOSITE CANTILEVER BEAM

The paper deals with the influence of delamination on mechanical characteristics of a composite cantilever beam. The main goal of the performed Finite Element Analysis (FEA) was to recognize the general nature of damage influence on the composite structure' properties by extraction of eigenfrequencies and eigenmodes. The two main geometrical parameters, i.e. the size and location of a delaminated zone were taken into account. In addition, a simple analysis of the friction coefficient on the beam dynamics was performed. The numerical simulations were done in the ABAQUS/CAE commercial software environment. The models contained a single local delamination with appropriate contact definition. The defect length changed from 10 to 100% of the overall beam length. The results obtained for two different sequences of plies show the significant effect of delamination on the composite structure mechanical properties. In particular, the location of the delaminated zone had a non-uniform influence on the decrease in subsequent eigenfrequencies, which in some cases could help to avoid resonance. In the paper, analysis of the numerical results concentrated on the first five eigenmodes and on small and moderate-sized defects. The importance of other factors, e.g. friction coefficient or boundary conditions, as well as prospective experimental verification of the numerical results were also considered. In the performed analyses, glass-epoxy material data were used.