Reliability and Sensitivity Analysis for Micro-Meteoroids and Orbital Debris Protection Models using first-order Reliability Methods (form).

Abstract This Thesis provides a probabilistic assessment of the micro-meteoroids and orbital debris (MMOD) impact protection structures. The assessment is based on first-order reliability methods that use Ballistic Limit equations traditionally used by NASA for the design of shields. The research demonstrates how the structural reliability methods can be implemented into the aeronautics and astronautics field. NASA is continuously developing new techniques that allow the consideration of the uncertainty that exists in the design of their space structures. Nevertheless, some of their design approaches are still deterministic. For example MMOD ballistic limit equations used for the design of the MMOD protection are deterministic models. A reliability analysis was performed using the structural reliability methodology in order to account for the uncertainty that exists in the variables used in the Ballistic Limits Equations. The Hasofer-Lind First-order reliability method, and the implementation of the Rackwitz-Fiessler transformation were used for the calculations of the probability of failure of the models analyzed, as well as for the calibration of the reliability-based safety factors. Three types of shields were considered: 1) monolithic shields, 2) Whipple shields, and 3) multi-shock shields. It is shown that probabilistic approaches can significantly improve the design process of the models since the uncertainty of the parameters used is fully taken into consideration and processed rationally