Theoretical and numerical model to study the interlayer gap phenomenon during robotic one shot drilling of stacked materials

Abstract

Nowadays in different industrial fields, especially in aircraft manufacturing industry, the use of stacked material plays a relevant role. To allow the correct assembly of parts, one shot drilling is the best option to avoid misalignment and increase the productivity. In this context, the formation of the interlayer gap and its consequences in terms of final hole quality and structural integrity is a relevant aspect that need to be investigated and reduced. The growing push towards the implementation of automated drilling solutions offers the advantage of using the robot end effector for the minimization of this phenomenon, but few works offer a useful analytical study of the robot-workpiece interaction in terms of force based on real operating boundary conditions. This work aims to provide a simplified theoretical model to study the interlayer gap phenomenon and to predict the clamping force required for its reduction by using a robot end effector on metal stacked plates. Both experimental and finite element analyses were carried out in order to validate the results of the proposed theoretical model. The results obtained in this study showed that the proposed simplified one-dimensional theoretical model allow to obtain suitable results despite the complexity of the phenomenon studied.