Photogrammetry Analysis of a Hypersonic Inflatable Aerodynamic Decelerator Structural Test Article
Loading...
Author(s)
Li, Lin
Braun, Robert D.
Cassell, Alan M.
Advisor(s)
Editor(s)
Collections
Supplementary to:
Permanent Link
Abstract
Analysis was performed on photogrammetry data of a 6m Hypersonic Inflatable
Aerodynamic Decelerator (HIAD), an inflatable stacked torus used to aid in atmospheric
entry, to understand its structural dynamics. Photogrammetry data was obtained during
wind tunnel testing under various loading conditions. Test parameters included the
freestream dynamic pressure, yaw angle and internal inflation pressure. In addition, two
HIAD configurations were analyzed, the basic stacked torus (Baseline configuration) and a
second configuration adding a torus near the shoulder to aid in rigidity (Tri-torus
configuration). The analysis includes estimating the deflection of the HIAD under loading as
well as calculating the standard deviation relative to the mean deflection and the frequency
content of the dynamic response. Under load, the deflection angle for each configuration
ranged from 1° to 3° (1σ). The photogrammetry data showed that the oscillatory motion
increased with higher dynamic pressure but was insensitive to yaw angle. In addition, the
analysis showed that the standard deviation of the HIAD shape with respect to the average
deflection increased while moving radially outwards. However, the standard deviation
values calculated from different camera pairs were inconsistent as a result of their distances
to the test article. The frequency analysis showed that each radial member behaved similarly
to a rigid oscillator, having the same frequency content of motion along each radial direction
and increased amplitude when moving radially outward. Both the frequency and shape
standard deviation analyses showed that the motion of the HIAD was piecewise continuous
in the azimuthal direction. These discontinuities are also likely due to the location of
different camera pairs. The photogrammetry data is a valuable dataset providing insight
into the static and dynamic response of the HIAD under loading. However, inconsistencies in
the camera resolution need to be accounted for and higher temporal resolution will improve
the fidelity of analysis.
Sponsor
Date
2014-01
Extent
Resource Type
Text
Resource Subtype
Paper
Rights Statement
Unless otherwise noted, all materials are protected under U.S. Copyright Law and all rights are reserved