Analytical Investigation into the Helicopter Vibration Resulting from Main Rotor Blade (MRB) Ballistic Damage.

Abstract

The effects of main rotor blade ballistic damage on helicopter vibration are investigated using a comprehensive helicopter aeroelastic analysis code. Ballistic damage to the rotor blade is represented in the blade structural model as well as in the aerodynamic analysis. Each blade is treated as being composed of elastic beams undergoing flap bending, lead-lag bending, elastic twist, and axial deflections. The dynamic response of multi-bladed rotor systems is calculated from nonlinear periodic normal mode equations using a finite element in time scheme. Results are calculated for a typical soft in-plane hingeless rotor helicopter with several damage configurations. Blade damage effects are determined in terms of blade mode shapes and frequencies, blade aeroelastic response, blade bending loads, and hub-fixed system vibration. Blade dissimilarity because of ballistic damage can induce a large vibratory component with its frequency the same as the rotor revolution (1/rev) on the helicopter system.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1999
Accession Number
ADA365514

Entities

People

  • Ki C. Kim

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Abstracts
  • Aerodynamic Characteristics
  • Aerodynamic Forces
  • Aerodynamic Loading
  • Bending Moments
  • Blade Tips
  • Dynamic Loads
  • Dynamic Response
  • Equations
  • Failure Mode And Effect Analysis
  • Frequency
  • Harmonic Analysis
  • Helicopter Rotors
  • Military Research
  • Resonant Frequency
  • Structural Components
  • Vibration

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Aerospace Engineering
  • Structural Dynamics.