An engineering model for the design of cut-backs in ribbed panels

This paper deals with the modelling and analysis of ribbed panels with ‘cut-back’ ribs. A critical point in the design of these members is on the determination of the occurring forces and stresses - in particular in tension perpendicular to grain - at the end of the ribs, potentially inducing a splitting failure. Thus, ribbed panels with cut-back ribs in practice always have to be reinforced by appropriate methods (e. g. self-tapping screws or glued-in rods). The open question for the designer is on the determination and the intensity of the design force for the reinforcement.
In this contribution a pure analytical solution procedure based on a simple engineering model has been used. A detailed discussion on modes of load resistance and corresponding deformations has been made, taking into account effects of geometrical & mechanical properties of the components, cut-back length, component-interface properties and load intensity. As a result, simple expressions for the prediction of forces in the reinforcement under transverse loading situations were obtained. All results and discussions may also be applied to systems of beam-beam as well as plate-plate composites with cut-backs and notches of the lower component respectively.