Prof. Hans-Peter Monner

Recent Developments on Fluid Actuated Morphing Unit Structures (FAMoUS)

DRL Braunschweig

Morphing of thin control surface structures like winglet trailing edge tabs require highly integrated actuation. One approach is to use so called Fluid Actuated Morphing Unit Structures (FAMoUS) which are orthotropic structure-actuation units that elongate upon fluid pressurization. These unit structures are composed of reinforced elastomeric chambers and their development is motivated by their allowable integration in tight spaces and potential high work output, thereby enabling morphing in thin wing regions. This presentation will show results from manufacturing and laboratory testing of small prototypes, which are being used for fine-tuning finite element models for the purpose of designing a FAMoUS morphing winglet demonstrator which is to be subsequently manufactured. The finite element modelling features nonlinear hyperelastic material models using experimental data and hydrostatic fluid elements which provide information for the fluidic systems design , such as overall architecture, sizing of pumps etc. Mass and stiffness information are also determined which are used for investigating aeroelastic characteristics of the control surface. These preliminary aeroelastic analysis have been conducted to get a first glimpse of the dynamic behaviour of this morphing system in interaction with the overall wing and winglet. These analyses consider a worst-case scenario and a systems failure, resulting in substantially reduced stiffness. Aspects of control are also investigated in this work whereby fiber optic
shape sensors are used for monitoring control surface deflection and are to be integrated with the fluid pumps to provide closed-loop control. This is a necessary feature since the internal fluid pressure state needs to be adapted to changing external loading conditions in order to hold a given setpoint. Recent developments on the multidisciplinary aspects as mentioned above will be presented in this talk.