Structural Identification of Mir using Inverse System Dynamics and Mir/Shuttle Docking Data

The goal of this work was to determine if it is feasible to use Mir/Shuttle docking data to perform Mir damage detection. A time-domain technique called a Remote Sensing System was proposed as an approach. The method uses inverse structural dynamics to identify physical characteristics of a structure which can subsequently be used for damage detection. The RSS method was demonstrated for a numerical simulation of Mir/Shuttle docking assuming that sensors were collocated with Mir docking location. Several fixed interface Mir modes were identified from the computed RSS pulse responses using the Eigen System Realization Algorithm and then correlated with ta finite element representation. The method was then applied to the combined set of docking data from Mir/Shuttle missions STS-81, STS-89, and STS-91. Two modes were identified that correlated very well with FEM fixed interface modes. Finally, projections of the Mir and FEM RSS pulse responses onto the individual docking data sets were compared for changes in the structure. Overall, the results produced by this work appear to indicate that Mir was in an undamaged state, at least with respect to docking excitation, at the time of STS-91. The significance of the contribution of the RSS approach is that it is not affected by the nonstationarity and nonlinearity associated with the Mir/Shuttle docking interface, and docking forces at the interface do not have to be measured. 2