Aircraft Structural Reliability Analysis Based On Improved Response Surface Method

At present, the response surface method has been used widely in structural reliability; especially many different methods improved from the classical response surface method have applied to various fields. Several methods of this paper also based on the classical response surface method to improve the efficiency by reducing the number of sampling under the premise of ensuring the accuracy. And these improved response surface methods will be applied to reliability analysis of aircraft wing.These methods improved from the response surface method are as follows:1) For the accuracy is not enough of the fitting response surface method, this paper propose the interpolation response surface method based on the piecewise cubic hermite shape preserving interpolation, although this method can obviously improve the accuracy, but need to select a large number of sample points;2) To the shortage of the classic response surface method convergence insufficiencies slowly, this paper improve the center point interpolation in iterative process, this method can quickly converge to a true solution nearby;3) For the coefficient f as a constant in the iteration process of the classic response surface method, this paper improve a variable f into the classic response surface method, this method can reduce the value range of sample points in the iteration process, fast locate to the true solution nearby;4)For fitting the real surface with highly non-linear, this paper improve the mixed response surface method that was combined by the radial basis and the response surface method, this method can improve the fitting precision;In addition, according to actual condition, this paper also analyzed the finite element model of one wing. These improved response surface methods and the reliability calculation methods of the probability design module (PDS) in ANSYS software respectively were used to calculate the reliability of wing, and to compared the advantages and disadvantages of the two methods and to checked the advantages of these improved response surface methods in practical project with its development in the future.