Simulation And Improvement Of Minibus Crashworthiness For Two Types Of Frontal Impacts

Minibuses have become more and more popular and got more and more sales domestically due to its low cost and economical and practical features, and thus gained more and more interests from automobile manufacturers. The passive safety of minibuses has developed significantly with the fierce competition and people’s growing safety awareness. In order to establish in an unassailable position in the competition, the safety performance should not only pass national mandatory regulations, but also conform to higher criteria, such as C-NCAP star-rating. This paper relates to the improvement made to body structure of a certain minibus from the perspective of crashworthiness of two kinds of frontal impacts.The paper firstly introduces the research method and current state of automobile’s crashworthiness, gives overview of finite element theory and software used in the analysis herein, then introduces the modeling process of the vehicle and the precautions in the modeling process, such as mesh quality, spot weld simulation, material parameter setting and the like.Then this paper performs simulation calculations on the two types of frontal impacts. By 100%RB (Rigid Barrier) impact simulation, the analysis of the experimental result and stimulation result proved the precision and confidence of the simulation model, the target of 100%RB impact is to lower the acceleration of the B-pillar of the body so as to reduce head injuries to the passengers, and the specific measure is to improve the energy absorbing structure of the front rail by orthogonal experiment design method; by 40%ODB (Offset Deformable Barrier) impact simulation, the target of 40%ODB impact is to reduce the intrusion of components of the passenger compartment, such as A-pillar, steering column, pedal and the like, and the impact mechanism is analyzed by mass–spring model, and the improvement measures are determined to reinforce the rigidity of the passenger compartment to reduce the intrusion of components of the passenger compartment and specific improvement measures made to the components of the passenger compartment are also proposed and achieved good results.At last, the two solutions about the two types of frontal impacts mentioned above are integrated together and the simulation calculations of the two types of frontal impacts are performed, with the result that there are conflicts about the requirement of the front rail’s energy-absorbing structure from the two kinds of frontal impacts. Therefore, optimization design are made to the front rail’s energy-absorbing structure by multi-objective optimization method and finally an improved idea is acquired that can take two kinds of frontal impacts in to consideration: first from the perspective of 40%ODB impact, the rigidity of the passenger compartment should be guaranteed, and then optimization design are made to the front rail’s energy-absorbing structure by multi-objective optimization method.