Helicopter main rotor blade made of fibre reinforced composites experience complex load spectrum during its service life. These aeroelastic loads tend to cause various type of damages in the rotor blade such as fibre failure, matrix failure, interlaminar delamination. These defects not only initiates from aeroelastic loads but also sometimes from process variations or raw material variations such as resin richness or starvation. In the present study, finite element simulation is carried out on main rotor blade root to study the fibre and matrix damage using Hashin damage criteria for assessment of damage region, delamination using cohesive elements at ply-by-ply level using submodeling and virtual crack closure technique. The virtual crack closure technique is used to obtain the energy release for modes of fracture during the progression of delamination based on predetermined crack length. Experimental results obtained are compared with finite element results. Copyright © 2016 by the American Helicopter Society International, Inc. All rights reserved.