Study On Weight Estimation Method For Aerospace Plane

Weight estimation is a very crucial content in preliminary design of the aerospace plane. Aircraft weight significantly affects its take-off and landing performance, carrying capacity, flight performance, fuel consumption. Meanwhile, it serves as the reference data in the aerodynamic analysis, structure strength and stiffness analysis, flight performance and controllability and stability analysis. Primary methods of aircraft weight estimation include the empirical method based on statistic formula and the theoretical method based on structure finite element. Aiming at weight estimation pro blem about the aerospace plane, this article researched on two kinds of method, one of which is based on empirical formula, and the other is based upon finite element. The main contents are as follows:1) Some statistical experiential formulas about aerospace plane's weight were collected, sorted according to the component type, with their sources and range of application explained. Weight estimation programs of each component were coded and validated using known data. The results showed that weight estimating method based on experience formula was easy to use, and computed very fast, but its accuracy excessively relied on designer's experience and the application range. The sensitivity of each component weight to the various parameters was studied with the experiment analysis in the software Isight.2) Parameterization of the aerospace plane wing was studied. Comprehensive utilization of CATIA and Patran secondary development technique, wing structure CAD and finite element modeling were programmed. Then wing structural weight estimation procedure based on the finite element method was established, realizing the automatic parameterized modeling of the wing, reducing the complexity of the finite element method to calculate weight, improving the efficiency.3) Aiming at the wing of aerospace plane, two kinds of structure scheme were designed. The structure finite element models of two wings were generated quickly by the programs. The mechanical characteristics of them were analyzed on several conditions and then the structural weight was calculated, proving the feasibility of weight estimation procedure based on the finite element. Analysis results indicated that the accuracy of the procedure was guaranteed and it was more efficient than conventional methods. Comparing the mechanical properties and weight, advantages and disadvantages of the two schemes were analyzed. On the basis of the relatively more reasonable scheme, the structure thickness of different wing regions was optimized, providing reference for the structure design of the aerospace plane's wing.