COMPUTATIONAL DESIGN AND OPTIMIZATION
                              OF LIGHTWEIGHT ARMOR

                                George A. Gazonas

                          U.S. Army Research Laboratory
                   Weapons and Materials Research Directorate
                  Composites and Lightweight Structures Branch
                    Aberdeen Proving Ground, Maryland   21005



      ABSTRACT

         This talk outlines a methodology for the computational design of
      armor structures using fully automated optimization software tools.
      The computational tools essentially link formal nonlinear parameter
      estimation algorithms with computational finite elements with an aim
      towards developing optimal yet robust armor designs for lightweight
      composite multilayered armors for Future Combat System (FCS)
      vehicles.  A global-local optimization (GLO) software package[1]
      developed by Lawrence Livermore National Laboratory (LLNL) is linked
      to the three-dimensional transient structural dynamics finite element
      code known as DYNA3D[2]. Two examples are presented that illustrate
      the utility of the fully automated, transient optimization software
      tool.  The first example considers the optimal design of a
      multilayered composite armor subjected to impact by a
      fragment-simulating projectile (FSP).  The second example considers
      the classic Taylor impact problem and the possibility of "reverse
      engineering" flow parameters of the constitutive model using both
      gradient "variable metric" methods and genetic algorithms (GA).

      1. M.J. Murphy. "GLO ? Global Local Optimizer User's Manual." Report
            UCRL-MA-133858, Energetic Materials Center, Lawrence Livermore
            National Laboratory, 1999.
      2. J.O. Hallquist and R.G. Whirley. "DYNA3D User's Manual?Nonlinear
            Dynamic Analysis of Structures in Three Dimensions." Report
            UCID-19592, revision 5, Lawrence Livermore National Laboratory,
            1989.