Design and Analysis of a Hybrid Segmented Sliding Panel Morphing Skin System

Abstract

<p>This thesis presents a rigid morphing skin that is designed to enclose an underlying morphing mechanism and serve as a reliable load bearing protective cover for the enclosed mechanism. The morphing skin, named the passive panel skin system, is a series of geometrically discretized telescopic panels enveloping the underlying morphing mechanism. These panels are connected to the morphing mechanism through a set of linkage systems and each panel can passively reorient with respect to the shape changes of the morphing mechanism. The passive motion of the skin system is governed by constraint equations that correspond to the parallelism and gap distance among adjacent panels.</p> <p>Two main problems have been solved in this thesis: kinematic modeling and force modeling of the proposed system. The kinematic modeling describes the passive panel motion through the simultaneous evaluation of nonlinear constraint equations. The number of the said equations is 3 times the number of panel pairs. The complexity of the kinematic model increases as panel discretization becomes finer. Although the passive panel skin system does not incur additional forces during morphing, there is however an inherent aerodynamic and mechanical gap issue. To solve this, a smart material named shape- memory polymer (SMP) is applied to join the adjacent panels and form a gapless morphing skin. Since SMP is a hyperelastic material, a nonlinear modeling method is applied to model the flexible joints of the gapless panel skin. A force model is developed to address the incurred forces from flexible joints. The model correlates the forces and moments of each joint to the actuation forces of the morphing mechanism. This model helps determine the additional force required from the actuators of the morphing mechanism to achieve the companion motion of the morphing skin as described in the kinematic model of the morphing mechanism. The force model is implemented over a modified workspace that simulates the panel enclosed morphing mechanism.</p> <p>The contributions made in this thesis on kinematic and force model of the passive panel skin system set a foundation for the development of a full morphing system consisting of a morphing mechanism and a morphing skin.</p>