DYNAMIC ANALYSIS OF MULTIPLE CAR VEHICLES USING COMPONENT MODES. VOLUME I. ANALYSIS

The report documents the development of a computer program to predict the dynamic characteristics of multiple car trains. The approach, of analysis by subsystems forms the basis of this program. The method of component mode synthesis is then used to obtain an accurate approximate solution with a reduced number of coordinates and thus reduced computing time. Previously the method of component mode synthesis has been applied to undamped elastic structures. In this report the method is extended to general linear systems, that is, systems which include significant damping and asymmetric matrix coefficients. The modal coordinates to which the original equations of motion are thus transformed are no longer real but complex, and include velocity as well as displacement information. Included is a complete description of the program, a user's guide and a sample program. A limited amount of numerical results have been obtained and these are discussed. These preliminary results show that modal frequency and damping obtained by component mode synthesis after truncating half of the component modes agrees to within a couple of percent of exact solutions which include all of the modes. As expected, the mode shapes did not agree quite as well. (Author)