Hypersonic inflatable aerodynamic decelerator technology can enable future missions to Mars and the outer planets. Such missions require large drag devices to safely decelerate the vehicle during planetary entry. Key technologies include flexible materials that will protect the spacecraft from the thermal environment experienced during reentry into the atmosphere. An improved understanding and predictive capabilities of the decelerator behavior is necessary prior to flight. Accurate prediction of the decelerator structural response under various external pressure distributions is necessary through use of modeling and simulation. In order to validate the predictions obtained from finite element analysis and computational fluid dynamic analysis, a series of ground and flight tests have been conducted. Sub-scale models were used for these tests due to the cost and limitations of test facilities. This investigation models the decelerator configuration with the intent of constructing less computationally-expensive models to approximate the structural response. Modeling results are compared with similar results in the literature as well as idealized closed-form equations. These results include the meridional shell force resultants in the tori, spars, and restraint wrap fore and aft side. Due to symmetry, a three dimensional, 15° wedge model and a two dimensional, axisymmetric model are used. After the model was developed, the equilibrium deflected solution and Von Mises stresses were calculated and analyzed. These results correlated well with the closed-form equations and results from literature. This investigation demonstrates that sufficient accuracy can be obtained using two-dimensional, axisymmetric models.
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