Session: 03-06: Design and Optimization of Intelligent Structures

Paper Number: 111187

111187 - Design and Optimization of the Conformal Surface for an Adaptive Structure 

This work considers an adaptive structure that contains a discrete actuating system supporting and morphing a conformal surface. The discrete actuating system is a series of five hinged panels connected in series that have gaps between each other when aligned and laid flat. The conformal surface creates the outer mold line of a morphing aircraft in supersonic flight. The discrete actuating system has the edge panels' outer hinges rotated using torque tubes and the center panel linearly displaced with a linear actuator. The discrete actuating system uses Shape Memory Alloy based torque tubes. However, the gaps between the panels let air into the aircraft and does not allow the airflow to be continuous. A conformal surface solves this issue by attaching to the plates and covering the gaps in all configurations. This conformal surface both prevents the air from flowing into the aircraft and creates the continuous outer mold line. The panel system is actuated into three desired configurations during flight. These three configurations are concave, convex, and flat. The conformal layer is composed of two parts, a continuous outer layer that can handle large strains and a discrete inner layer that can handle large pressures and prevent the outer layer from buckling. The inner layer's properties are the main design variables of the structure. The main contribution of this work is the development a Finite Element Analysis model capable of taking this discrete adaptive surface of actuated panels with gaps between them and designing the conformal surface that creates as continuous an outer mold line as possible for all three configurations. As close to a second order parametric continuity of the principal axes (i.e. mean curvature is minimized) is optimal. The optimum design for this structure is validated with an experimental test on a prototype. The displacements on the prototype are measured using Digital Image Correlation. 

Presenting Author: Alejandro Martinez Texas A&M

Presenting Author Biography: Alejandro Ian Martinez is a first-generation college student that graduated with his undergraduate degree in Aerospace Engineering in Spring 2021 and with his Masters of Science degree in 2023 at Texas A&M University. His undergraduate research was in the Electrochemo-Mechanical coupling of reduced Graphene Oxide (rGO) with Dr. Dimitrios Loufakis. During the Master's program, he was involved with the NASA ULI project on a Morphing Supersonic Aircraft under Dr. Darren Hartl and Dr. Dimitris Lagoudas. His graduate program was focused on Materials and Structures.