Comparative Study and Development of Nonlinear Material Model for Morphing Aerospace Applications

The SADE project aim is to create a gapless high lift device at wing’s leading edge with an objective to reduce the airframe’s drag and enable laminar flow. Keeping in mind the surface smoothness of the new high lift devices, a new actuation system has to be developed. The surface requirement leads to a complex mechanical actuation system. A new idea is to continuously support the surface skin through a system of inflatable actuation tubes. This concept makes use of actuation tubes made of Flexible Matrix Composite (FMC) material, which is rubber enforced with stiff fibers. The present work focuses on the study and development of the FMC material model whose test data has already been collected at EADS Innovation Works. At first, a comparison of test data with the standard existing material models was carried out. The material was also simulated using Finite Element Analysis (FEA) software ABAQUS to observe its behavior under different material properties. In later part of the study, an analytical model was developed as a function of stress, strain and fiber angle. This was followed by the derivation of a new strain energy function in terms of invariants. The analytical and strain energy function was well in agreement with the experimental results and it was decided to implement the energy function in finite element model as part of future work in order to properly simulate the FMC actuation tubes.Validerat; 20120423 (anonymous)