Structural modeling, analysis and optimization method comparison for spacecraft design

Commercial software Patran/Nastran and the developed Engineering System for Structural Optimization Software ESSOSII were used to demonstrate a structural modeling, analysis and optimization procedure for a practical spacecraft design. The designed spacecraft is a geosynchronous three axis stabilized communication satellite. With pre­processor Patran, the structural components were mainly simulated as laminated honeycomb panels which possess efficient stiffness. The static and dynamic analyses were conducted with Nastran to find the maximum stress and displacement as well as the basic frequencies and corresponding modes of the structural model. Some analysis results such as frequencies of initial structure were used as limitation values of constraints in the structural optimization procedure. The facesheet thickness and sandwich heights of the honeycomb panels were chosen as design variables to minimize the objective function corresponding to the whole structural satellite weight. The Sensitivity Analysis and the Two-level Multipoint Optimization method helped to reach several weight minimum designs of the spacecraft structure under different conditions. It can be seen the initial design is improved from the final results. The present work also shows the design procedure is reasonable for practical engineering problem.