Bending Mechanics of Cylindrical Skins for Morphing Aerospace Applications (Postprint)
Abstract
Shape-changing aerospace structures explore the trade-offs between structural performance and efficiency. Herein, a morphing cylinder is optimized to minimize both its work to actuate in bending as well as structural deviations from a prescribed shape. Based on derived linear elastic mechanics of a cylindrical shell in bending, it was determined that favorable designs have high radial stiffness and low axial stiffness. Since no single material can satisfy strain and stiffness constraints, we investigate novel ringed composites composed of both rigid and elastomeric materials. Several distinct archetypal designs were evaluated via finite element analyses to predict the bending kinematics and structural responses of each. Additively manufactured cylinders were fabricated to corroborate these predictions. Digital image correlation was used during bending tests to generate strain contour plots of prototype surfaces. Strong agreement between model predictions and experimental measurements was observed. By systematically varying the dimensions of each archetype via finite element parametric studies, a set of non-dominated designs that satisfy all design criteria was generated. It was determined that flexible skins reinforced with embedded rings were optimal at low (8-15 Nm) and high (>250 Nm) values for the work to articulate and flexible skins reinforced with helical springs were optimal at moderate values (15-250 Nm).
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 07, 2019
- Accession Number
- AD1116554
Entities
People
- Darren J. Hartle
- Geoffrey J. Frank
- Jeffery W Baur
- Maria R. Rashidi
- Patrick P. Walgren
- Ryan Seifert
- Wesley A. Chapkin
Organizations
- Air Force Research Laboratory Materials and Manufacturing Directorate