Integrated Design Optimization Of Macro Fiber Composites And MFC-Layout Form For Morphing Structural Shapes

One of the key objectives in the structural design of aircraft and spacecraft is the capability of accurate shape morphing that can meet various operational and environmental requirements for enhanced performance of the flight vehicles. Macro Fiber Composite has been widely used due to its light weight, adaptability, fast response and high driving strain energy density. So the way of improving accuracy and stability of aircraft deformation control has become an important research topic. For the shape control problem of aircraft wing this paper analyses the influence of macro fiber composite’ internal structural parameters, establishes an integrated optimization of multi-parameter control model, develops a wing plate actuating by macro fiber composite with the minimum mean square error optimization goal between required surface and actual surface. The experimental results validate the effectiveness and feasibility of integrated optimization design of actuator structural parameters and morphing structural shapes which are proposed in this paper. The content of the research is focused mainly in the following aspects.First, designs and analyses configuration of macro fiber composite. An integrated optimization model of actuator structural parameters was established for maximizing the actuating performance through designing electrode width and spacing, fiber thickness and the volume fraction of piezoelectric ceramic fiber. It can be clearly seen by the results that the MFC’s electrode width has a maximum actuating value. When the electrode spacing and fiber thickness decrease, the actuating strain increases, and when the fiber volume fraction increases, actuating properties also improve. But when we consider the restrictive factors which include the processing technology, electrical breakdown and brittleness, the all the above constraint conditions should be considered in determining the optimal specifications of the MFC to achieve the desired surface control.Second, formulates the optimization problem of voltages for achieving the shape morphing of aircraft wing based on the finite element algorithm. The optimal design models of a single voltage and multi-voltage control are established. The results of simulation show that the mean square error of the multi-voltage control is about 42.28% greater than the single voltage control for bending surface, just 3.82% for twisting and 26.71% for bending and twisting surface.Finally, presents an integrated design optimization method for morphing idealized aircraft control surfaces via a concurrent design of the layout of given number of macro fiber composite (MFC) actuators and their relevant controlling parameters. An integrated optimization model is developed with the goal of minimizing the deviation between a required shape and an actual one through optimizing actuator locations, angles, layer number, symmetry and control voltages subject to the constraints, such as the breakdown voltage of the MFC and the geometrical limit of MFC-actuators. Then the influence of the actuator number on the shape morphing accuracy is studied and the aircraft wing with 6 actuators for experiment is prepared. The experimental setup was constructed and the test results show a good correlation between the desired shape and the actuated one by using the present MFC-layout and controlling parameters, which in turn validates the effectiveness and feasibility of the proposed method.