Research And Implementation Of Free Interface Mode Synthesis

Free-interface component mode synthesis method (Free-interface CMS) is one of themost effective methods for dynamic analysis of complex structure, and has been widelyused in practical engineering. Free-interface CMS ensures the accuracy of dynamicanalysis, while greatly reduces the kinetic equation of system. And it is easier achieved inthe experiment.In this paper, the development history and research status of the CMS are reviewedbriefly. The advantages and disadvantages of the fixed-interface method and free-interfacemethod are discussed. The basic algorithm of free-interface method and thecalculation method of substructure’s residual modal is introduced in detail. The methodsof processing rigid mode and the definition of link substructure are studied, too. Based onthe exact residual dynamic flexibility for damped systems, a free-interface CMS isproposed for proportionally and non-proportionally damped systems. This method canbe unified with the free-interface method of undamped systems after degradation. Thismethod maintains original-space without having to use the state-space equation of motionsuch that it is efficient in computational effort and storage capacity.A procedure to implement of free-interface CMS based on Nastran solver and DMAPlanguage is proposed and a system is developed. The system modules are designedaccording to the basic algorithm of free-interface method. The results of this system wereverified through practical examples and compared with the holistic analysis results ofNastran, which proved the effectiveness and correctness of this system in deal withdifferent situation.