| Composite was widely used in aerospace because of its high strength, modulus, designable rigidity and strength. But high price has becoming an obstacle for its use. The overseas investigation shown that digital manufacture technology is effective for cost saving. However, composite parts are mainly made by hand domestically, it is very slow and quality is not able to be assured. So research on composites digital technology is very urgent. Optimized packing is a key process of composites digital manufacture, and it belongs to NP complete problem.Based on the study of various packing algorithms, the author proposed a new rectangular packing algorithm, a hybrid heuristic optimizing algorithm and a new irregular packing problem, and combined these algorithms with composites plies packing specialties to develop a composites packing software. The main achievements and creative ideas are given below.The rectangular packing problem not only deals with packing of 2D rectangular parts but also plays an important role in solving irregular packing problem. In order to solve the problem of rectangular parts optimal layout with dynamic constraints, a on-line packing algorithm for order-given parts is proposed——Lowest Outline Searching Algorithm based on its mathematical model. It satisfies the requirement of BL (bottom left) condition and overcome the shortcomings of other algorithm for some patterns. What's more, according to the test compariation with other algorithm such as BL and Lowest herizatinal Line Algorithm, it shown that the algorithm is very effective. And this algorithm is used for many drawings packing and mass printing, which is helpful to save time and paper.Rectangular packing problem mainly consist two fields, which is geometry caculation and compound optimization. Single packing method is only for geometry calculation, but packing order is also very important to optimized layout. In this paper a hybrid optimization algorithm of simullated annealing and Lowest Outline Searching Algorithm was proposed to solve small scale rectangular packing problem and the ways to improve its efficiency was studied. It can get best layout for more than ten rectangles, while for about one hundard rectangles, it is more than 100 times faster than other Simullated annealing based optimization algorithm with almost same material usage.Also ant colony based optimization algorithm was put forward to solve large scale packing problem. The ant colony was used to search a good packing order while Lowest Outline Searching Algorithm is used get the pattern for the ordered parts. Many experiments results show that ant colony based optimization is much faster than simulated annealing based hybrid optimization alrightm; it is very suitable for large scale rectangular packing problem.The irregular packing problem is among the most difficult class of packing problem and has been studied for many years. This paper concentrate on solving the problem from two aspects,that is the method based on graphics calculation and the rectangular packing based on method. For the rectangular based one, graphics calculation, rectangular packing and interactive adjust technologies are combined together to get the enclosed rectangular of irregular parts and packing them. For graphics calculation method, the no-fit polygon algorithm was studied for calculating the relative position for two polygons to save the un-used margin. The existing method based on slope graph is mended and a new boundary slide algorithm was proposed to calculate NFP. The new one is suitable for any two polygons and it is easier than what have been used.Based on the main procedure of composites digital manufacture, the specialty of composite ply packing is analyzed and summed up. According to composites ply packing property and based on the study of theory and algorithms mentioned above,the author designed and developed a software for packing composite layers, which can be integrated with the composite digital manufacture system.
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