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

Di¤erent formulations based on multibody dynamics are shown to be suitable for the development of a methodology for the impact simulation and crashworthiness design of railway vehicles. The proposed design methodology comprises di¤erent computer-aided tools of increasing complexity and accuracy which can be used with greater advantage and e¦ciency in the di¤erent design stages of railway stock. In general, the crashworthiness design methods and associated multibody dynamic tools which are presented in this paper require information to be obtained from numerical or experimental crush tests of speciÞc structural components, subassemblies and critical energy absorption devices normally located in car extremities. This hybrid feature lends to the present design process various e¦ciency gains as a result of a better understanding of the crash and di¤erent collapse mechanisms and ease of use. To access the merits of the present methodologies some new designs are discussed and the application of the proposed numerical tools is illustrated for di¤erent structural conÞgurations of car extremities. A formulation for the sensitivity analysis and optimization of planar constrained mechanical systems is also presented. An example of crashworthiness design of an end underframe model of a railway car is solved to demonstrate the use of the methodology.