Equivalent Continuum Finite Element Modelling of Plate-Like Space Lattice Structures.
Abstract
A method involving finite element modelling of an equivalent continuum formulation based on matching the strain energy and kinetic energy is developed for truss type lattices with pinned joints. The method is shown to give modal results consistent with those obtained using detailed finite element modelling of the pin jointed space lattice structure, even for structures with fairly small numbers of repetitions of an identical unit cell. Feedback controllers designed using reduced system models derived from these modal results using Modal Cost Analysis are shown to perform as well as controllers designed using the detailed analysis results. A micropolar plate continuum model of large plate-like repetitive space lattice structures with rigid joints are derived. A plate finite element is based on this continuum model with micropolar rotations and transverse shear deformations included as nodal degrees of freedom. The natural frequencies and mode shapes are calculated using this element for a free floating hexahedral plate-like space lattice structure. These natural frequencies and mode shapes are compared to those calculated using a detailed finite element model (with every structural member modelled by a beam-column element) for several sets of frame member cross sectional properties. The static deflections of a centrally loaded and corner supported rectangular plate-like space lattice structure are also obtained and compared these two types of structural models.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1985
- Accession Number
- ADA160879
Entities
People
- S. E. Lamberson
Organizations
- Air Force Institute of Technology