Analysis of Structures with Rotating, Flexible Substructures,

Abstract

A new methodology has been developed for the developed for the dynamic analysis of flexible structures, flexible structures, parts of which may beenperiencing discrete motion relative to other parts. It provides the capability of representing the continuum deformations typically treared using finite element methods. In addition, it provides the capability of representing the discrete motion at joints traditionally available with multibody methods. After decomposing the structure into substructures and associating a frame of reference with each substructure, the equations of motion for each substructure can be written explicitly including contributions due to the frame of reference generalized coordinates. By expanding the set of constraints to include constraints that eliminate the redundancy introduced by the frame generalized coordinates, the equations of motion become amenable to solution. The first digital computer program using this methodology, the General Rotorcraft Aeromechanical Stability Program (GRASP). GRASP is limited to applications involving steady state rotation, but extension to arbitarary motions (including spin up) can be accomplished by the sellective retention of nonlinear terms in this formulation.

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1987
Accession Number
ADA178903

Entities

People

  • A. S. Hopkins
  • Peter Likins

Organizations

  • United States Army Aviation and Missile Command

Tags

DTIC Thesaurus Topics

  • Computer Programs
  • Computers
  • Digital Computers
  • Equations
  • Equations Of Motion
  • Finite Element Analysis
  • Flexible Structures
  • Mathematics
  • Mechanical Structure
  • Redundancy
  • Rotary Wing Aircraft
  • Rotation
  • Steady State
  • Transient Response Analysis

Readers

  • Control Systems Engineering.
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Robotics and Automation.