Research Of Auto Body Beam Section's Optimization

In the automotive industry, the design of beam section is mainly based on the experience and methods of simulation. This approach is neither efficient nor reliable. During the developing proceeding, the design result of cross-section is so late that it will affect the developing of new models. However these problems can be solved by using method of optimization. During the process of structural design of the vehicle, the optimization method is very useful but has challenge. Optimization method is a powerful tool which helps designers using less time to design high-quality products in the vehicle developing proceeding.This paper takes VCD-ICAE (Vehicle Concept Design-intellectualized CAE) systems for the background, in view of the needs in the phase of vehicle concept design using a shape optimization method to start the relevant beam optimization studies.VCD system is software for vehicle concept body design which is based on UG NX5 platform, exploited secondly by using UG OPEN / API language. The system can create quickly auto parameterized geometrical model of concept phase by template technology, then the parameter is designed and the pre-process is finished quickly, the system can analyses stiffness and modal, then the post view and produce report is created. This method analyses sensitivity of auto beam and panel and the parameter can be optimized. It can instruct and help the user to get satisfying design scheme. So the method quicken the process that auto body structure concept design phase and the time that auto body concept design phase is shorten and the difficulty of operation is reduced.A key technology of VCD-ICAE system is the beam parameter optimization for concept vehicle. The mechanics characteristic of beams directly determines the auto body's characteristic and it is ensured by the beam section, but beams'section has the characteristics of complicated shape. The design of pillar sections had been performed by the trial and experiences, this approach is neither reliable nor effective. These problems can be solved by the optimization methods. The cross-section optimization method integrated in the VCD system is an upgrade to optimize function. The optimization modular of VCD system also includes OFFSET method, wide cross-section method and so on. The integration of this optimization theory in this paper makes the optimization module functions better and more effective for the application of concept body beam structure optimization.The contents of papers around the body beam optimization studies, mainly includes the following aspects:Introduction of optimization platform VCD-ICAE system, including auxiliary module of the system——Section Tool module.To create concept auto body template that applied in VCD-ICAE system. The establishment of templates includes the two main processes, first is on parameterized geometrical modeling, that is, with beam and plane structure using KF technique to establish body template in UG; to create section lines base on detailed model of vehicle body and do some work for lines adjusted, then establish section data base. The template has also been calculated in torsion, bending and modal case verifying the reliability of this technology for simplifying.Through a beam optimization theory, this paper discusses the beam section optimization method of concept vehicle model which bas been achieved in VCD-ICAE platform. Also this paper fetches the formula for calculating properties of beam section in order to be carried out in computer system.This optimization method were integrated in the two modules of the VCD-ICAE systems——Section Tool module and the vehicle optimization module. The research work of this paper was carried out through these two modules. During optimization process, the paper calculates and analyzes the sensitivity value of beam structure parameters in the case of torsion and bending, and in accordance with the shape optimization theory this paper optimizes the beam section's shape and ultimately lowering the quality of the body with meeting the requirements of vehicle stiffness.