Research On Efficient Placement Technology Of Composite Laminates With Complicated Boundary

Automated Fiber Placement can,according to the actual needs,increase or decrease the prepreg tows in real time.It is more suitable for forming irregularly shaped laminates with no need of further largescale processing,and the scrap rate is greatly reduced.By increasing the production efficiency of automatic fiber placement and shortening the production cycle,the advanced composite materials at low cost can be achieved.Aiming to achieve the goal of placing complex boundary composite laminates with high efficiency,this paper carries out relevant research.Firstly,the first part of this paper focus on the efficient placement of planar laminates.According to the structural characteristics of the machine,the polygonal expansion and contraction algorithm of parallel polygonal lines are proposed.Combined with the minimum envelope rectangle of the polygon,the combination states of the two polygons are obtained.And then,the optimal combination state is found by abutting collision between the polygons.Based on optimal combination state,it is easy to get the geometrical topology.Accordingly,we can obtain the position and boundary information of the component on the mold.And the initial trajectory could be obtained by the intersection of line segments.The next step is post-process of initial pavement trajectory,which mainly includes the coverage analysis,the shortest feed yarn length,the key points and the boundary information to finish the trajectory planning.Secondly,the second part of this paper is about the efficient laying of planar laminates.In order to place a plurality of laminates with the same fiber direction,shape and size at the same time on the curved surface,certain requirements are needed on the placement curved surface type and the geometrical topology of the component.An orthogonal projection algorithm based on free curved surface meshing is proposed to determine the component’s position and boundary information on the curved surface.On the basis of this,we propose a radial expansion algorithm to determine the position relation between the trajectory point and the boundary of the component,and then use the projection method to obtain the initial trajectory at the boundary of the component,and then post-process it to complete the trajectory planning of the planar and multi-component placement at the same time.Then,we study the bidirectional post-processing algorithm.The position and separation method is adopted to separate the movement process of the wire-splicing machine into two parts: the movement of the rotating spindle and the movement of the wire-splicing head.And we construct the fiber placement equipment and the rotation matrix of trajectory based on the movement structural characteristics of the double-direction fiber placement equipment,and the track information on the die is converted to the movement center of the fiber placement equipment.Considering the compensation of the spindles by the spindle rotation,the position and posture information of the fiber placement equipment are calculated.Aiming at the situation that the machine runs to the singular point and the mold with the edge is put on,the corresponding solution is put forward.Finally,we will write in the Microsoft Visual C + + development environment for the preparation of the software and use the OpenGL graphics processing functions to achieve the visualization of placing trajectory and to verify the trajectory simulation of the deposition.We will also verify the correctness and rationality of the plane and curved surface of the proposed multi-component placement trajectory.Then the actual placement experiments will be carried out by bidirectional fiber placement equipment.The results show that verifying the algorithm of this paper can realize the forming of the two-way and the multi-component placing at the same time,and then achieve the purpose of efficiently placement of the laminates with complex boundary and composite materials.