Finite element modeling of low floor mass transit bus and analysis of frontal impact scenarios

Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering"December 2006."There is no international regulation for the frontal collision of the buses, protecting their occupants and partners in traffic. There are some regulation such as ECE R-80 which deals with strength of seat structure of the coaches and their anchorages strength. There is increasing need to focus issues like occupant protection and full scale crash testing regulation for buses. This thesis attempts to collect possible subjects required for international regulation required for crashworthiness of transit buses. This research attempts to develop and validate a model of transit bus for all three impact conditions. The full finite element model is developed with help hypermesh software and its validation and analysis is done with help Ls-Dyna nonlinear finite element solver. The cost of actual testing and secrecy maintained by manufacturers make research process difficult and increase the importance of computer simulations. To boost the research of crash worthiness of transit need for computer model is felt. This thesis examines several frontal crash test procedures and evaluates how well each procedure meets the objective. This validated model is used to analyze various real world impact scenarios and its analysis with European and federal regulation. This validated model is used to extract crash pulses of various impact scenarios at the center of gravity of the bus. These extracted crash pulses are applied to the madymo model to estimate the injuries to occupants of the bus. This thesis discusses the design aspects of bus frontal impact behavior as one of the main subjects of bus crashworthiness and results of previous full scale tests comparing the Fem simulation results carried out on the transit bus