A Study On The Occupant Dynamic Response And Injury Characters In Frontal Impact Of Coach

Coaches are the main tools of highway passenger transport in China.Because of its large size,high full-load quality,large passenger capacity,and poor protection measures for passengers,coaches are prone to cause a large number of casualties in traffic accidents.In order to reduce the casualties in front collision accidents of coaches,many regulations and standards on passive safety performance of coaches have been promulgated,but they are limited to the general requirements of body structure strength.So far,there are no clear standards for the test methods and numerical simulation methods of occupant protection.In this paper,the motion response and injury characters of occupants during the front collision of coaches are studied,which can provide reference for the protection of occupants in the accident.In this paper,the finite element model of a 6120 coach is established,and the frontal crash simulation tests with initial velocities of 30 km/h and 50 km/h are carried out.The energy absorption,structural deformation and acceleration response of seat position in passenger area are analyzed and evaluated.In order to simulate the effects of geometric nonlinearity,material nonlinearity and contact nonlinearity on occupant damage in secondary collision,a multi-rigidbody model,a passenger zone finite element model and a seat belt model were established.Then the dummy-vehicle system model is coupled by adjusting the space position,restricting the hinge and defining the contact.Through a large number of simulation experiments,the occupant dynamic response and injury characters under different positions,different restraint forms and different initial collision velocities are deeply explored.In order to improve the restraint effect of two-point seat belts during frontal collision,5 design parameters of passenger seats and 2 design parameters of seat belts were selected,and simulation tests at different levels were designed by using single factor variable method.The influence of these design parameters on occupant dynamic response and injury characters in the secondary collision is studied through the simulation test of occupant restraint system.Finally,the orthogonal test method is used to optimize the main influencing parameters,which significantly improves the protection performance of coach passenger restraint system during frontal crash.The research results of this paper provide reference value for the test methods,numerical simulation methods and the standards formulation of passenger protection in coach frontal crash,and have certain guiding significance in the design and optimization of coach body structure and restraint system.