Modeling and Simulation of Stage Separation Based on Probability Analysis

Abstract

Stage separation of aircraft was a complex variation process of force. It was influenced by deviations of aircraft and environmental disturbance, which would result in the simulation inconsistent with the actual one, even lead to collisions occur between separators. In this paper, a method of aircraft design based on probability analysis is introduced that is applied to simulation and analysis of stage separation with guide pins scheme. Firstly, dynamic model was derived from the constraint force equation to analyst relative motion of separation bodies during stage separation processing. Then probability models of deviation factors were given. Inducing the probability model of deviation factors into the simulation process, using real boundary as design constraint, and according to the degree of reliability or robustness, quantitatively add design margin to design constraints, and relax the margin limitation by satisfying the reliability of constraints. Finally, Monte Carlo simulations of stage separation process were adopted under combined action of multiple random deviations. Distribution and relative motion of separated bodies in inertial frame was obtained. The statistical analysis of Monte Carlo simulation result was compared with reliability and failure domains to evaluate the effectiveness of separation schemes. Because the probabilistic design method above-mentioned has the characteristics of “deviation allowance and margin free”, it can improve the overall performance of aircraft and obtain a robust and reliable separation scheme.