Abstract: Composite materials have been widely used in aerospace field for its high strength to weight ratio, high modulus, desirable fatigue resistance properties and other fine qualities. But, it is influenced by a variety of factors, such as material properties, ply orientations, curing system, mould material and so on. As a matter of fact, the shape of the composites after curing is not certain, spring-back may be caused, and even lead to scrapping of the cured part and mould due to deformation over tolerance. This article, through spring-back experiments on different parts of wing spar, simulates the spring-back of the demonstrator by finite element method. Then, we linearly amend it by comparing with the actual measured result, and acquire the amendatory formula, finally calculate the amendatory value, use it in the research and manufacturing of 3 m spar, and validate the amendatory formula.

Key words: composites, spar, spring-back, correction