Research On Automated Fiber Placement Trajectory Planning Method Of Adjustment Algorithm Based On Structural Design For Surface With Holes

Trajectory planning, an essential process of Automated Fiber Placement (AFP), can greatly anddirectly affect the properties of components, while significantly influence the forming quality, theproducing efficiency, the material utilization rate, and the manufacture cost. In this dissertation,shown are the researches conducted to improve the tow placeability and to solve the trajectoryplanning problem for surface with holes.Firstly, a novel algorithm for AFP trajectory planning was introduced and applied into meshedsurface. In order to minimize the deformation of the prepreg tows, the adjustment algorithm divertsthe placement direction from the original one (which is generated according to structural design) tothe adjusted one (which is closer to the geodesic direction) in a curtain principle, on the premise of thestructural design requirements. Summarized are the former-proposed Fixed Angle Algorithms (FAA),analyzed are the benefits of planning on meshed surface, and also is solution by STL (StereoLithography) format files. Then the FAA and adjustment algorithm were both applied into the meshedsurface.Secondly, promoted was a method for path generating for surfaces with holes, and suggestedwere the three post-treatment methods for trajectory planning. To generate trajectories on a surfacewith holes, the surface should be preprocessed, i.e. be joined into a whole one without any holes bythe surfaces in and out of the hole boundaries. Furthermore, as the surface information is obtained bySTL, a topological reconstruction method was promoted. The “constant” trajectories can be generatedon the surface with the application of a curtain algorithm. And then, according to the hole boundaries,the trajectory point information could be treated. To conduct boundary treatment, introduced are the“iteration method” and the “projection method”. Through precision and efficiency analysis, the lattermethod was considered to be the more suitable one. In addition, described are the three differentprinciples for post-treatment, a) all saving and backward extending, b) all saving and forwardextending, c) saving out of the shortest length, and analyzed were the efficiency and the overlap rateof them as well.Finally, the methods were realized by C++and SQL programming in Visual C++6.0development environment, and were verified through simulation and experiments. Trajectories wereplotted with the application of CAD software, and the results showed that the algorithm and themethod to be proper and reasonable. Compared to FAA, the experiment trials demonstrate the improvement of the adjustment algorithm and the increasing of deflection angle can indeed release thestrain of the prepereg tows. And the AFP process of open hole structure, demonstrates the trajectoryplanning method for surface with holes.