Research On Closing Performance Of Side Swinging Door Based On Rigid-flexible Coupling

With the rapidly development and progress of the society,people pay more and more attention to the user's experience of vehicles.Excellent shutdown performance has become an important advantage for automobiles owing good competitiveness.In this paper,the virtual prototype technology was used to study the closing performance of the side swinging door.In the pre-design and early development stage of a vehicle door,a multi-body dynamics model was established to analyze the dynamic characteristics of the door closing performance.The main research contents and results are as follows:(1)The rigid body models of the handle assembly,latch,and hinge of a side swinging door were established.After finishing the flexible treatment of the inner and outer panels and the draw bar of the lock system,a rigid-flexible coupled multi-body dynamics model of the side swinging door was built.The minimum and maximum deviation between the simulated values and actual vehicle test results are 4.5%and 11.2%,which means the models are accurate and reliable.(2)Based on the rigid-flexible coupled multi-body dynamics model,the closing energy simulation of each subsystem of the side swinging door was carried out.The results show that the initial driving energy and the gravity potential energy of the door provide energy for the door closing;After ignoring the air-binding,the seal has the greatest impact on the closing energy,and the seal consumes about 7.4J,the energy lost is about 30%of the total energy;and the friction of the hinge,the force against the stopper and the energy required to overcome the friction of the lock are all small,about 1.5J,3.7J,0.3J,respectively.Energy consumption accounts for 6%,15%and 1%.(3)The influence of the change of the hinge inclination angle on the lifting and falling of mass center during the door opening as well as the influence of the mass center position on the minimum closing speed during the door closing were studied.The simulation results show that the influence of changing the forward tilt angle and the inward tilt angle simultaneously on the position of the mass center of the door is equal to the sum of the influence values of the forward tilt and the inward tilt angle respectively;when the mass center of the door is offset to the front of the vehicle 0.03,0.06 and 0.08m,the minimum closing speed increases 6.7,10.1 and 11.8 percent respectively,when the mass center of the door moves 0.03,0.06 and 0.08m toward the rear of the vehicle,the minimum closing speed decreases 4.3,12.1 and 14.1 percent respectively.Based on the rigid-flexible coupling virtual prototyping model,influence of the main factors,such as hinge,limit device,sealing strip,door lock,door characteristics(hinge angle,door gravity),which affecting the closing performance of side swinging doors,were studied in this paper.And the influence rule of the mass center position on the minimum closing speed of side swinging doors was also analyzed.These provide both theoretical and methodological guidance for the study of side swinging door closing performance.