Research On The Injury And Prevention Of Driver For A Monocoque Coach Under Frontal Impact

As a main means of transportation, coach plays an important role in the modern life. However, the frequent occurrences of coach collision accidents in recent years made more and more people pay attention to its crashworthiness. As the front of most coaches in the market are flat with engines place in the rear, they can easily get severely damaged in crash accidents, and this puts the driver and front passengers in great injury risk or even death because of the short energy absorption space in the front of coach. Considering the driver is the key person for keeping the control of the coach in the event of an accident so that the safety of the passengers will be ensured,improving the driver's safety is crucial in a crash accident. Based on the above situation, this paper conducted a series of studies about the injury and prevention of driver for a type of monocoque coach under frontal impact. The main contents of this paper are as follows:First of all, the matching and development process of the coach driver restraint system(DRS) was proposed according to references published at home and abroad and the collision characteristic of coach. Put a monocoque coach as research object,this paper established the FE model of coach in frontal impact and DRS using the geometrical model provided by a manufacturer.Secondly, frontal safety simulation researches of coach body structure and DRS were conducted refer to the vehicle frontal crash safety regulation GB11551-2014,and the problems in models were summarized based on the impact results.The improvement designs of coach body structure in frontal impact safety were carried out in order to ensure the driver has enough living space. Firstly, through compare the crashworthiness of different types of energy-absorbing tubes, a type of energy-absorbing tube with relative good crashworthiness was applied to absorbing impact energy of the coach; secondly, the improvement design of coach frontal chassis structure strength was carried out; finally, the crashworthiness of coach was improved obviously through optimizing the number, wall thickness and length of energy-absorbing tubes. The simulation results showed that energy absorbed by energy-absorbing tubes account for 48.2% of total impact energy, the effect of energy absorption was significant.Lastly, the improvement and optimization researches of DRS were made basedon an improved coach body structure. Choosing dummy's head, chest and femur injuries as evaluation index, the simulation analysis of the initial configuration of coach DRS was carried out. The improvement designs of DRS were made according to its problems that were found in the analysis. Finally, in order to better protect the driver, optimization matching of DRS was conducted through sensitivity analysis.The optimal results show that the injury values of dummy's head, chest and femur declined obviously and well satisfied the requirements of regulation. This paper's research work provided a certain reference and guidance for the formulation of coach crash safety regulation and the development of coach crash safety.