S.Y. Hwang, H.S. Jeong, N.S. kim
Sogang University, Korea
pp. 65 - 68
Keywords: deformation on roof, thermal analysis, blowing agent, exterior curvature, optimum design
Exterior curvature of the vehicle is one of the most important factors to evaluate the quality of the vehicle. During oven process, exterior of the roof is deformed. However this can be only identified under polarization test after vehicle is completely assembled. To predict and minimize the deformation, finite element method is used to form a model which calculates the change in curvature before and after the oven process. In order to represent the phenomenon by simulation, foaming behavior of blowing agent that is dependent to temperature is considered. Also, Flexural function which calculates the difference in slope is proposed to calculate the difference of exterior curvature. In order to validate the model, the location of the deformation occurred in experiment and simulation is compared which showed good correlation. Using the simulation, minimization of the deformation is carried out. First, sensitivity analysis is performed to investigate the influence of the process variables. As a result, rail location, blowing agent length and blowing agent location are the most influential variables. Then Response Surface Method is used to find the optimum values. Finally, the maximum flexural function value is decreased by 12 percent using the optimum values.