Abstract:Engineers devote themselves to reduce the weight of structures and to improve their performance. The Thrust-Weight Ratio and Weight-Factor of the aircrafts are highly improved because of widely use of composite material. Based on the requirements of development of aerospace and aviation industry, the thesis is concentrated on the investigation of composite door structure progressive design and analysis. And the optimum design of composite plate and shell structure is studied. Based on composite material door structure of a aircraft, the FEM is built and carried out by using of Nastran & Patran. The progressive optimization is finished by Hypersizer. The author obtains the optimum results according to the design requirements. The parameters of cross section, angle of each plies and stacking sequence are calculated. Methods of establishment of FEM and procedure of progressive optimization are summarized. According to the results of analysis, after the optimization, the mass of structure decreases and the structure meets the required design target.