The characteristics of carbon fibre reinforced plastics allow a very broad range of uses. Drilling is often necessary to assemble different components, but this can lead to various forms of damage, such as delamination which is the most severe. However, a reduced thrust force can decrease the risk of delamination. In this work, two variables of the drilling process were compared: tool material ...

The use of fiber reinforced plastics has increased in the last decades due to their unique properties. Advantages of their use are related with low weight, high strength and stiffness. Drilling of composite plates can be carried out in conventional machinery with some adaptations. However, the presence of typical defects like delamination can affect mechanical properties of produced parts. In t...

Damage in composite materials occurs at multiple scales, from matrix cracking and fiber/matrix debonding to ply delamination, and is complicated due to the different failure mechanisms interacting with the composite microstructure. Recent progress in the development of advanced techniques for structural health monitoring (SHM) has been aimed at techniques capable of sensing damage in situ and i...

This study uses observations of mechanisms from previous work (the “undamaged cone”, toughness and extent of permanent out-of-plane deformation) to examine parametrically their effects on residual compression after impact (CAI) strength using finite element models. In previous experimental work, tougher material systems exhibited up to 30% greater CAI strength for a given damage area. Based on ...

Electrical Impedance Tomography (EIT) as an imaging technique producing a 2D or 3D impedance image (conductivity or impedivity) of the subject under test. It can be used for delamination detection and evaluating the damage location, size, strain and severity for Structure Health Monitoring (SHM) of aerospace composites i.e. Carbon-fibrereinforced polymer (CFRP) composites. Keywords—Electrical I...

In aerospace and many types of civil infrastructure applications, the use of adhesive-bonded composite joints have been constantly increasing. In this study, fracture behaviour of adhesively bonded single lap joint (SLJ) with pre-existing damage at the interface of free edge of the top adherend and adhesive along the width of the joint is studied by strain energy release rate (SERR) approach us...

Delamination monitoring in carbon fiber reinforced polymer (CFRP) laminated plates is crucial to ensure the integrity and safety of the structures that accommodate the plates. To identify delaminations in CFRP laminated plates, the two-dimensional (2D) curvature mode shape method is a prevailing method that features instant and simultaneous determination of the presence and location of the dela...

Abaqus/Standard simulation of Lamb waves in smart composite plates is investigated for detecting delamination type damage. Composite plates typical of aerospace structures are used and a PZT actuator is surface bonded to excite Lamb waves. Abaqus model of composite plate uses layered solid elements. Piezoelectric (PZT-5H) actuator is modeled using piezoelectric elements that have both displacem...