Research On Crash Safety Of A New School Bus Body Structure

Crash safety of a new school bus was mainly studied in the paper.According to the newest national standard for school bus,the new high-strength body called “bird cage” and high-safety structure called “energy-absorbing front” were developed to improve the crash safety in order to satisfy the technique target of the school bus.The original and advanced body is characterized by the vertical and horizontal connection of ?-shape loop and side impact beam.There are three prominent characteristics.Firstly,the strengthened front and rear bumpers are stamping molded by thick steel plate and welded to the frame.Secondly,?-shape beams surround the frame from the front to the rear one by one.Thirdly,the external molded side impact beam surround the frame from the bottom up.Energy-absorbing front structure is built by the combination of all stamping parts.The passive safety of the new school bus body structure is good enough to protect the safety of the driver,the care staffs and the children.The school bus is modeled by CATIA software.And the Finite Element model is established and verified through module analysis in HyperWorks software.Then,frontal crash,side crash,rear crash,top static pressure and side rollover of the school bus are simulated and analyzed in LS-DYNA software.Three prototypes are prepared according to the results and installed by the corresponding test equipment.The top static pressure test for the school bus is conducted according to the safety requirement to verify the top structure strength.The side rollover test is conducted according to the strength requirement to verify the superstructure strength.The bus frontal crash test is focused on in the paper.The method of frontal crash test is proposed according to the passenger protection requirement and seat system strength requirement under the condition of the frontal crash.The school bus frontal crash test is conducted by arranging six dummies(including a driver dummy,a care staff dummy and 4 6-year-old child dummies),58 channels(acceleration,force,displacement)and about 100 body displacement measurement points.The data collected during the test show that the new school bus has better crash safety.Simulating results and test results all show that the new school bus has good performance of resisting shear destruction,rolling deformation and collision destruction to offer enough survival space for the passengers and to protect them from injure in a variety of accidents.Meanwhile,the method of the new school bus crash safety is studied and test data and experiences are accumulated by Computer Aid Design modeling,Computer Aid Engineering simulating,the top static pressure test,crash tests and the side rollover test.All of the studies in the paper provide a sound basis for the further improvement of the school bus safety.