| With the rapid development of the socio-economic and coach transportation, themileage of Chinese high-grade highways, and the operation of passenger car ownershipwas showing a rising trend, the coach has absolutely become the main of passengertransportation,was the most convenient and quickest means of transport for people, butthe rate of traffic accidents for coach must not be ignored. The serious traffic accidentscaused by coach rollover in recent years, posed a serious hazard to lives and the safetyof property, has aroused widespread concern. In view of this, China is stepping upefforts to amend the GB/T17578"Provisions of the Coach Superstructure Strength", toimprove the regulations and strengthen the technology of coach passive safety.Through relying on the scientific project of Chongqing Municipal Bureau of Qualityand Technical Supervision which has been undertook by National Coach QualitySupervision and Inspection Center, adopting the method of combining coach test andsimulation analysis, the rollover safety of coach superstructure has been researched inthis paper,which was hoped to offer valuable references to the amendment of GB/T17578and the structural design of coach companies. the main researchs of thisdissertation mainly includes:①The statistics ofcoachtraffic accidents in recent years have beenanalyzed. Thedefinition and hazards of rollover have been described. The research status anddevelopments of coach rollover at home and abroad have been introduced, from threeaspects of the regulations and standards, experimental study and simulation analysis,through searching a large number of domestic and international references. Theresearch purposes and significance of this paper have been summarized. The mainresearch methods of this paper have been introduced. The main research contents ofthis paper have been put forward.②The theoretical basis of the revealed finite element method has been illustrated,and the functions and features of two finite element analysis software have been brieflyintroduced. The basic process and key issues of finite element analysis for coachrollover have been summarized. According to the theoretical basis of the revealedfinite element method, prototype data and regulatory standards, the whole process ofthe establishment of coach rollover finite element model has been elucidated in detail, and the simulating calculation for it has been performed.③Relying on the experimental conditions of the Chongqing Academy of vehicledetection, the rollover crash test of a real coach has been carried out. The differencesbetween the test and simulation results have been compared and analyzed, basing onthe deformation of column and magnitude of body acceleration. The validity of themodel has been verified,and it has established the foundation for coach rollover safetyevaluation and structural improvement.④The methods of evaluation for coach rollover safety have been illustrated, fromthe strength of superstructure and acceleration of coach body. On the basis of theevaluation method for superstructure deformation index, a new evaluation method forstrength of coach superstructure has been presented based on the column deformationindex. According to the datas of coach rollover test, an improved scheme for coachsuperstructure has been provided, and the improve effect by the new evaluation methodhas been assessed, the results have verified the improved measures is reasonable andeffective.The innovative points of this paper:①A new evaluation method of coachsuperstructure strength has beenput forward,and evaluation indexes have been provided.②The maximum, average and root mean square value of body acceleration havebeen proposed to evaluate the effectiveness of structural improvements as evaluationindexes. |
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