Response Surface Method Research Of Structurare Reliability

Because of the advantages of simple calculating and easy programming, the responsesurface method is widely used in the aircraft reliability analysis. But the computationaccuracy of classical response surface method is greatly affected by the forms of responsesurface functions, the numbers of experimental points that selected, the position ofexperimental points and many other causes. Meanwhile, contrapose a actual aircraft structure,the non-linear levels of the limited state function is unknown, these problems confine the useof RSM. Contrapose the above causes, this thesis is based on classical response surfacemethod and improved the classical response surface method. On the promise of the accuracy,reduce the numbers of experimental points, optimize the position of experimental points andthe forms of the response surface function. main content of this thesis is as following:1) This thesis based on the Moving Least Square technique, by improving the fittingmethod of the classical response surface method, which can better reflect the realrelationships between the experimental points and the structure limited state function,increased the calculation accuracy of the reliability.2) This thesis introduces the GIVENS transformation, by rotating and updating theexperimental points which used in the classical response surface method, make theexperimental points nearby the structure limited state function more reasonable, increased thefitting accuracy.3) This thesis presents a new improved response surface method which lays out theexperimental points on the approximation tangent plane, makes the experimental pointsdistribute in the plane in a large extent and nearby the structure limited state function. Byjudgment the numbers of experimental points and the correlation coefficients, then select theoptimum form of response surface function, and make the response surface function moreflexible approximate with the structure’s real limited state function. compared with the abovetwo methods, this method not only ensure the local high accuracy at the design points, but also ensure approximate the limited state function in a large range. This method increases thefitting accuracy and computation accuracy. computing the reliability of a aircraft wing withthis method.4) This thesis primary studies the numeral computation method on structure reliability,analysis the HDMR numeral computation method which apply to structure reliabilitycomputation. And analysis the advantages and disadvantages of HDMR.