Study On Structural Improvement Of Door Seals Based On Simulation Analysis

Seal is the key part to ensure the sealing performance of cars. As core parts of car seals, door seals including primary seal, secondary seal, glass run seal etc. have very important effects on a variety of car quality indices such as door glass movement smoothness, door closing force and noise isolation performance at high speed etc. Therefore, the design of door seals is the most important in the car seal design.It is studied in this paper, that the finite-element-method based simulation analysis can be used to substitute for the traditional design method which purely relies on experiences and prototype assembly in the structural design and improvement of car seals, using door seals as research objects. The new design method can not only help to evaluate the design proposal before prototyping, but also provide much useful information for design improvement, while keeping low design cost and short design cycle. Thus, the simulation analysis based on seal design will become the main seal design method. The work of the paper would provide beneficial discussion and reference for the application of simulation analysis in seal structural design and improvement. The main work of the paper includes the following aspects:1. First, a systematic study and summary on the fundamental theories of the simulation of seal deformation behavior is carried out on the basis of collection of literature and analysis of state of the art. It includes seal material models, solving process and results analysis based on commercial finite element code MARC, etc. This sets up the theoretical and technological bases for the application of simulation analysis methods in the seal structural design.2. Using simulation analysis based on the finite element method, the compressive deformation behavior of a typical type of glass run seal in the glass insertion process is studied. Judgment on whether the seal design is acceptable or not is made according to the compressive deflection and support forces of the big and small flips got from the simulation analysis. The irrational factors of the original design are determined based on the seal deformation animation and stress distribution, and the improvement proposals are put forward accordingly. The effectiveness of the simulation analysis based on structural design and improvement method is verified through a real design example. All the simulation results, the part performance tests and the system durability tests for the proposed new design support the verification. Additionally, the commonly used countermeasures and flow chart for structural improvement of glass run seal are generalized.3. Both the insertion/pulling off and the bending deformation behavior of a typical type of secondary seal are studied with the finite-element simulation analysis method. Judgment on whether the seal design is appropriate or not is made according to simulation results: judge the design for the insertion/pulling off deformation based on the insertion and pulling-off forces, and judge the existence of seal bulb sinking problems by the bending deformation analysis. The irrational factors of the original design are determined on the basis of the seal deformation animation and stress distribution. Accordingly, the seal structural improvement proposals are put forward. The effectiveness of the simulation based on seal structural design and improvement method is again verified through a real design example of secondary seal: all the simulation results, the part performance tests and the vehicle assembly evaluation for the proposed new design support the verification. Furthermore, the general countermeasures and flow chart for structural improvement of secondary seal are summed up. 4. The summarized general countermeasures and flow chart for structural improvement of two types of seal set up the technological bases for serializable and standardized seal design and provide beneficial guidelines for similar product design of following projects.