Accession Number:

ADA091051

Title:

Evaluation of the Impact Computer Program as a Linear Design Tool for Bird-Resistant Aircraft Transparencies.

Descriptive Note:

Final rept. 1 Jan-1 Aug 78,

Corporate Author:

AIR FORCE FLIGHT DYNAMICS LAB WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

1980-03-01

Pagination or Media Count:

166.0

Abstract:

The use of a finite element structural analysis computer program called IMPACT to simulate the transient response of B-1 aircraft windshield panels to bird impact is discussed. For the two simulations accomplished, computed results were compared to experimental data acquired during bird impact tests of actual windshield panels. For the first case of a panel tested at ambient temperature the computed results were qualitatively accurate. Strain levels measured during the test exceeded those calculated by IMPACT, however, and the disagreement was attributed to the presence of geometric nonlinearities in the test structure the effects of which were not accounted for in the IMPACT analysis. For the second case of a panel heated to an outer surface temperature of 220 deg F the computed results were unreasonable. Disagreement between computed and experimental data was attributed to errors in the theoretical formulation or coding of IMPACT relating to its capability to account for the effects of elevated temperatures or temperature gradients within the structure. Continued development of IMPACT is not recommended a currently available fully nonlinear finite element program is identified which has more potential of serving as a transparency birdstrike analysis tool.

Subject Categories:

  • Aircraft
  • Numerical Mathematics
  • Computer Programming and Software

Distribution Statement:

APPROVED FOR PUBLIC RELEASE