Homogenization and Control of Lattice Structures

Abstract

Under certain natural conditions the dynamics of large, low-mass lattice structures with a regular infrastructure are well approximated by the dynamics of continua (e.g., trusses may be modeled by beam equations). Using a technique from the mathematics of asymptotic analysis called "homogenization," the author shows how such approximations may be derived in a systematic way that avoids errors made using "direct" averaging methods. He also develops a model for the combined problem of homogenization and control of vibrations in lattice structures, and presents some preliminary analyses of this problem. In section 2 he gives an example derived from Bensoussan, Lions, and Papanicolaou (1978) illustrating some of the subtleties of homogenization, particularly in the context of control problems. In section 3 he derives a homogenized representation for the dynamics of a lattice structure undergoing transverse deflections. He shows that the behavior of the lattice is well approximated by the Timenshenko beam equation, and that this equation arises naturally as the limit of the lattice dynamics when the density of the lattice structure goes to infinity in a well-defined way. The problem of vibration control of a lattice is posed and discussed in section 4. In section 5, he derives a diffusion approximation for the thermal conductivity of a one-dimensional lattice structure. This property is useful in analyzing new materials for large space structures. An operational calculus for homogenization is sketched in the Appendix.

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Document Details

Document Type
Technical Report
Publication Date
Mar 24, 1985
Accession Number
ADA451619

Entities

People

  • G. L. Blankenship

Organizations

  • University of Maryland

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Calculus
  • Conductivity
  • Crystal Lattices
  • Dynamics
  • Electrical Engineering
  • Engineering
  • Equations
  • Information Operations
  • Large Space Structures
  • Lattice Dynamics
  • Mathematical Analysis
  • Mathematics
  • Thermal Conductivity
  • Universities
  • Vibration

Fields of Study

  • Mathematics

Readers

  • Calculus or Mathematical Analysis
  • Computational Fluid Dynamics (CFD)
  • Structural Dynamics.

Technology Areas

  • Space