Abstract: In this article a new method for solving the normal stress in curved beams is established; it is based on the principle of stress superposition and the hyperbolically graphical method; many puzzles are avoided which may be occurred as in solving it in the ordinary way. First of all, a brief review of the methods on calculating the normal stress in curved beams has recommended, then the principles and procedures of the new graphical method of solution are discussed all in detail. At last, the examples for application have been shown. In most cases, this method gives a more accurate result and rather convenient; it can be used in the practical engineering calculation directly.

Key words: Bézier extraction, Integration mapping, Isogeometric analysis, thin-shell theory, unstructured T-splines