Drilling Process Simulation on Composite Laminates

Abstract

Despite of the fact that their physical properties made them an attractive family of materials, composites machining can cause several damages like delamination, fibre pull-out, thermal degradation and others. It is possible to derive the axial thrust force during drilling that causes delamination onset, using analytical models based on LEFM. In this work, a finite element model considering solid elements of ABAQUS® software library and own interface finite elements including a cohesive damage model was developed in order to simulate thrust forces and delamination onset during drilling. Results of thrust force for delamination onset are compared with analytical models. Three different configurations of fibre reinforced laminates are considered: carbon/epoxy laminates, glass/epoxy laminates and hybrid laminates. Values of interlaminar fracture toughness in mode I were obtained in DCB tests for all configurations. Results show that a hybrid interface consisting of carbon/epoxy and glass/epoxy plies has interlaminar fracture toughness in mode I similar to a carbon/epoxy interface. Consequences in terms of critical thrust force for delamination onset and propagation are discussed.