Abstract
The topicality of this study is defined by importance of passive safety ensuring of buses that are built on the light commercial vehicles chassis, according to the ECE №66 requirements. The main objective of the study is determination of the most optimal rollover simulation method in terms of calculation time minimization and the best agreement with experimental test results.
The experimental rollover crash investigations were made on body section framework of a bus constructed on the base of light commercial vehicles chassis. The results of experimental tests were compared with calculation researches data. The comparison between the simulation and test results was conducted by the residual deformation values of the section. The deformable material of the finite - element model was switched to rigid during free fall. The computer modeling without material switching was also concerned in order to determine the material switching influence on deformations.
The residual deformation values of the bus section were measured from the experimental test. The "stress-strain" curve was obtained experimentally for a bus section material. We can see good correlation between the computer simulation and experimental data, received in that study.
Comparative analysis of the experimental data and the results of calculation was carried out on the middle section of a typical bus body construction. The center of gravity location as well as body section symmetry didn't allow us to obtain different deformation values along the section length.
As a result of the analysis of the kinetic energy change during the rollover process it was found that the section's lower part detaching from the tilting platform shoulders significantly affected the energy amount dissipated during the impact process. The factors influencing the beginning of that detaching were determined.
It was found that rollover simulation with material switching from deformable to rigid, during bus free fall, allows us to receive more accurate result than simulation without material properties switching.
KEYWORDS – computer simulation, experimental test, passive safety, validation, light commercial vehicle.