Abstract:  For the current aircraft multidisciplinary design optimization (MDO) in computer simulation applications, the problem of poor description ability and adaptability with limited variables, in geometry modeling, stands out. According to the central idea of several common modeling methods, the concepts of graphic basis and curve correction are introduced, which present a greater scope to promote parametric description ability. Its application to CAD geometry modeling derives a set of CADbased semianalytical hybrid parametric geometric modeling method, which combines both the advantages, with a strong description ability and a simple realization. The cases of airfoil, aircraft parametric modeling and warhead shape optimization indicate that the CADbased semianalytical hybrid method for parameterization is compatible with the traditional method, combining the extended design space and the traditional one, which effectively improve the description ability and the adaptability of the parametric method. It has a certain significance to enrich the parameter selection and new design exploration in geometric modeling of MDO.

 Key words:  MDO, geometry modeling, CAD, graphics basis, semianalytical parameterization, curve correction