Woodruff School of Mechanical Engineering
GT Courtesy Listing
Folding and Deployment of Ultra-Thin Composite Structures
Prof. Sergio Pellegrino
Jet Propulsion Lab Research Scientist, California Institute of Technology
Thursday, February 4, 2010 at 3:30:00 PM
Guggenheim Building, Room 442
There is growing interest in novel deployable space structures made from ultra-thin composite materials with high modulus fibers. These lightweight structures are made as a single piece, at substantially lower cost than traditional deployable structures. When correctly designed, they can be folded elastically without any damage or permanent deformation, held stowed for a period of time, and when released they will dynamically self-deploy and latch into their fully deployed configuration. The challenges are ensuring fully-elastic folding, little or no time-dependent deformation while stowed, and reliable, damage-free deployment. In this talk I will present a study of the quasi-static folding and dynamic deployment of a lightweight boom with integral elastic hinges, consisting of a thin-walled tube with longitudinal slots. The simple geometry of this particular structure allows us to understand its behavior in some detail. Folding and deployment simulations have been carried out with the finite element package ABAQUS/Explicit, starting from the as-built, unstrained structure and incorporating a micromechanical model of the laminate based on the measured geometry and elastic properties of the fiber-matrix tows. Dynamic deployment experiments have also been carried out.
Sergio Pellegrino, Professor of Aeronautics and Civil Engineering at the California Institute of Technology and JPL Senior Research Scientist, received his Laurea in Civil Engineering from the University of Naples in 1982 and his PhD from the University of Cambridge in 1986. Between 1983 and 2007 he was on the faculty of the Department of Engineering, University of Cambridge. His main research focus is the mechanics of lightweight flexible structures and particularly problems related to packaging and deployment. In recent years one of his main interests has been deployable space structures made of ultra-thin composite materials; these structures are folded elastically and are able to self-deploy. Another area of recent research has been stratospheric balloons. Dr Pellegrino received the ICE James Watt Medal 2000; a Pioneers’ Award in 2002 from the Space Structures Research Centre, University of Surrey; AIAA Gossamer Spacecraft Forum Best Paper Awards in 2004, 2005, and 2006; IASS Tsuboi Awards in 2004, 2005, and 2007; the 2008 ASME/Boeing Best Paper Award; and the 2009 NASA Robert H. Goddard Exceptional Achievement Team Award. Dr Pellegrino is a Fellow of the Royal Academy of Engineering, a Fellow of AIAA and a Chartered Structural Engineer. He is a member of the Structures Technical Committee, the Balloon Systems Technical Committee, and the Gossamer Structures Program Committee. Dr Pellegrino has published over 200 technical publications.
Refreshments will be served.