Analysis of Structures with Rotating, Flexible Substructures Applied to Rotorcraft Aeroelasticity in GRASP (General Rotorcraft Aeromechanical Stability Program),

Abstract

The initial version of the General Rotorcraft Aeromechanical Stability Program (GRASP) was developed for analysis of rotorcraft in steady, axial flight and ground contact conditions. In these flight regimes, the material continua of the rotorcraft may experience deformations which are independent of time. GRASP can obtain this steady-state solution and can solve the eigenproblem associated with perturbations about such a steady-state solution. GRASP is the first program implementing a new method for dynamic analysis of structures, parts of which may be experiencing discrete motion relative to other parts. Application of this new method to GRASP, including substructuring, frames of reference, nodes, finite elements and constraints, is described in the paper. The library of finite elements includes a powerful nonlinear beam element that incorporates aeroelastic effects based on a simple nonlinear, aerodynamic theory with unsteady induced inflow.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1987
Accession Number
ADA178941

Entities

People

  • A. S. Hopkins
  • Dewey H. Hodges
  • Donald L. Kunz

Organizations

  • Georgia Tech

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Aerodynamic Forces
  • Air Flow
  • Computational Science
  • Coordinate Systems
  • Equations
  • Equations Of Motion
  • Flow
  • Flow Fields
  • Helicopter Rotors
  • Helicopters
  • Nonlinear Analysis
  • Relative Motion
  • Rotary Wing Aircraft
  • Standards
  • Steady State
  • Transient Response Analysis
  • Wind Velocity

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Computer Science.
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)