CRASHWORTHINESS ANALYSIS AND DESIGN USING RIGID-FLEXIBLE MULTIBODY DYNAMICS WITH APPLICATION TO TRAIN VEHICLES

Different formulations based on multibody dynamics are shown to be sui table for the development of a methodology for the impact simulation a nd crashworthiness design of railway vehicles. The proposed design met hodology comprises different computer-aided tools of increasing comple xity and accuracy which can be used with greater advantage and efficie ncy in the different design stages of railway stock. In general, the c rashworthiness design methods and associated multibody dynamic tools w hich are presented in this paper require information to be obtained fr om numerical or experimental crush tests of specific structural compon ents, subassemblies and critical energy absorption devices normally lo cated in car extremities. This hybrid feature lends to the present des ign process various efficiency gains as a result of a better understan ding of the crash and different collapse mechanisms and ease of use. T o access the merits of the present methodologies some new designs are discussed and the application of the proposed numerical tools is illus trated for different structural configurations of car extremities. A f ormulation for the sensitivity analysis and optimization of planar con strained mechanical systems is also presented. An example of crashwort hiness design of an end underframe model of a railway car is solved to demonstrate the use of the methodology.