Structural Strength Analysis And Design Optimization For A Certain Type Of Canopy

A certain type of airplane canopy is subject investigated in this thesis, the following subjects are studied: fatigue life prediction of plexiglas material, FEM analysis of static strength, buckling and modal, bird strike analysis and design optimization method of canopy based on multidiscipline design optimization technology.MDYB—3 plexiglas is primary material of canopy. Variation range of surface temperature is between -60 ~ 100 °C due to flight environment and flight state. In order to ensure safety of airplane and avoid fatal burst accident, research about transparency structural fatigue life is demanded. The fatigue behavior of MDYB-3 PMMA (Polymethyl Methacrylate) in uniaxial tension under cyclic loading of constant amplitude at different temperature is investigated experimentally. As a result, the curves at the typical temperatures are obtained and the fatigue life assessment equation considering temperature effect is established. The results of present investigation offer the basis and reference for the structural life evaluation analysis of canopy transparency.Canopy transparency is affected by different kinds of loads (pressurization loads, aerodynamic loads, temperatures loads, and so on), and resonance would occur with external shock excitation. For these reasons, some mechanical behavior of canopy needs to be studied in design process, such as static strength, Vibration and stability. Finite element models are built by analyzing features of real canopy. Calculated results are basis of multidiscipline design optimization of canopy.Bird-strike resistance performance is the key mechanical behavior of windshield and one of the flags of advanced technologies. Bird will flow because of enormous stress generated during compact is far larger than yield strength of bird, the bird is considered as fluid approximately. ALE method is used for numerical simulation of bird strike and strain responses of windshield are obtained. The results are basis of multidiscipline design optimization of canopy.Program module of parameterized modeling and finite element computation is developed using PCL language. The program offers technical support for realization of multidiscipline design optimization.Theories and current applications of multidiscipline design optimization are studied. Multidiscipline design optimization definition and optimistic algorithm are...