Computer Simulation of Canopy-Pilot Response to Bird-Strike.
Abstract
A computer program was developed for simulating the complete scenario of a bird-strike event: bird-canopy impact, canopy-pilot impact, and the resulting response of the pilot. The response of the pilot was simulated by a previously developed head-spine model, but in order to predict the degree of pilot injury or impairment, a skull brain model based on the maximum strain criterion was incorporated. Additional features which were developed for these simulations are (1) a plate finite element with the capability of treating geometric nonlinearities due to large deflections and material nonlinearities; (2) a contact-impact algorithm for treating bird-canopy and canopy-helmet impact and (3) a graphical display capability for illustrating the results of simulations. Simulations were first performed of bird-canopy impacts to determine the mesh refinement necessary to reproduce the magnitudes of experimentally observed deformations and the wave pattern of the observed displacment. It was found that only a very fine mesh proved satisfactory. This mesh could not be used in the computer simulations because of computer core-storage and cost limitations at our computer facility. Simulations of pilot response to canopy impact showed that the injury potential is quite sensitive to the initial impulse of the bird impact and its location relative to the pilot. A simulation with a 8 cm maximum deflection resulted in a head impact which was definitely tolerable. On the other hand, a 33% increase in this impluse was associated with irreaversible injuries.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1979
- Accession Number
- ADA080122
Entities
People
- E. Privitzer
- T. Belytschko
- T. Wicks
- W. Mindle
Organizations
- Northwestern University