Nonlinear Analysis and Optimal Design of Dynamic Mechanical Systems for Spacecraft Application

摘要

This research developed analysis and optimal designed procedures for planar as well as spatial mechanisms that are frequently used in space structures. A nonlinear finite element procedure developed originally for planar mechanisms during the initial stages of this research, has been modified considerably to handle complex mechanisms with sliding masses and mechanisms operating at relatively high speeds. The analysis takes into account the effects of geometric mand material nonlinearities, vibrational effects and coupling of deformations. Numerical results have been reported for certain mechanism examples. The effects of nonlinearities have been found to be significant on the dynamic behavior of mechanisms. Considerable progress has been made in developing a nonlinear finite element procedure for three-dimensional mechanisms. Numerical results obtained for some example problems indicate the validity of the current three-dimensional formulation. A new optimization algorithm has also been developed based on the Gauss method to handle various types of nonlinear constraints with the goal of reducing the number of analyses required to obtain an optimal design. Complete details of the nonlinear finite element procedures as well as the optimization technique are available in published papers, copies of which are included here in the Appendix. Because of the complex nature of the nonlinear analysis, which had to be repeated many times during the optimization process, considerable amount of computer was needed for this research.