The Study On Automotive Door Closing Effort Based On Sealing Strip Structure Optimization

In recent years, China has got the rapid development of automotive industry. There's more and more vehicles in the city, while the competition between the major car manufacturers have become increasingly fierce. The quality of vehicles has been the focus of customers' attention, and the perceive quality include door closing effort, economics, sound quality, etc. People also increasingly get high priority over others. According to JD POWER's studies, the bad perceived quality while closing door has been the major problems that customers complain about. Researchers abroad have done a lot of the door closing effort, and as domestic manufactures for the automotive quality requirements increasing, research about the door closing effort playing a important part.From the view of design point, there's many factors affect the door closing effort, such as sealing materials, the force generated from structure features, the structure and the axis' inclination of the hinge, the position of the weight center, air resistance during the door impact, the check link and stopper. And the biggest influence coefficient is the air resistance and the force generated from sealing. Since the changes in air resistance more difficult, more costly, and may also bring other problems, this paper present the methods by changing the structural design factors of door's sealing to improve the door closing effort, and then summarized the process of the sealing optimization.Many researchers domestic and aboard employed the finite element method to study the door sealing system, and got a lot mature operational means. However, the door sealing strip consist of the sponge rubber and dense rubber, and rubber is a kind of hyperelastic material, such material component has a strong nonlinear material behavior. With the loads of tensile, shear and compression, the rubber's mechanical response is the interaction effect of elastic, viscous and mullins result. In order to obtain the mechanical properties of rubber's hyperelastic parameters, the general means is based on the traditional uniaxial tensile, biaxial stretching and other methods. Due to the absence of test conditions, most domestic automotive accessories suppliers are not able to provide sufficient description of the mechanical behavior of the rubber materials, usually only available finished products'data under corresponding experiment(such as CLD curve of sealing).Even if the test data can be provided, but also spent much time and energy, and not conducive to the guidance in the design phase for the changes of the structure and material composition of the sealing system.The innovation of this paper is the combination of DOE(Design of Experiments) sampling method and Hybrid Algorithm Combining Ant Colony Algorithm and Generic Algorithm. A material parameters identification method by means of finite element method has been employed to obtain the parameters of sealing strip. Based on this method, the designer can easily establish relatively accurate finite elements analysis models, combined with the CAD to guide the structure optimization of sealing. In this paper, we provide a flow chart of the door sealing structure optimization, with this flow chart the simulation and optimization of the sealing strip will presents a time-saving and trouble-saving way.