Hope College Department of Physics and Engineering Research Experiences for Undergraduates Summer 2003 Project Summary

Project Title: Elastic and Plastic Responses of Curved Reinforced Shell Panels to Blast Loading
Student Name: Martha Luidens
Student’s home institution: Hope College
Research Advisor(s): Dr. Roger Veldman
Source of Support: FAA
 

This project investigates the response of pressurized commercial aircraft fuselage skin to an internal explosive detonation. Due to cabin pressurization, the net outward pressure on an aircraft structure increases with altitude, which increases aircraft structural vulnerability to an internal explosion. In order to simulate the response on an actual aircraft to various blast loading scenarios, two different models were analyzed using the finite element method. Both of these models were based on sample aircraft panels extracted from an actual Airbus A300 aircraft. The first structure simulated by FEA was the individual shell, designed to represent one fuselage section of the sample Airbus A300 shell. This model consists of the span of fuselage skin between adjacent stringers and frames. The second model analyzed, the panel shell, consisted of three fuselage surfaces and the supporting stringers (longitudinal reinforcements) between these sections. The purpose of these models is to determine the response of the fuselage skin to various blast loading scenarios with and without static pre-pressurization. Throughout the analysis each blast pressure loading has been conducted using pre-pressures of both 0 Pa and 62,053 Pa, which represent the two extremes of pressure differential between the inside of an aircraft and the surrounding atmosphere. Using the finite element software ANSYS and ANSYS_DYNA the location and magnitude of peak deflection and strains on the two shell models in response to the various explosive scenarios were determined. The results of the analyses of the individual and panel shells shows that the peak displacement for the blast loading cases occurs at the most central node of the shell. As the blast loading values increase for the six different load cases considered the peak displacement also increased. For the individual shell the first blast loading scenario showed peak elastic response and the final five analyses ended in plastic shell deformation. The peak strain occurred at the mid-side edge node for both shells. Analyses of the effect of pre-pressurization on both shell models indicated that for all blast loading cases considered there was essentially no change in peak shell displacements as the pre-pressure was increased from 0 Pa to 62,053 Pa.

Slide show of Martha Luidens' work