自动铺丝线型规划研究

发布时间：2018-07-07 10:15

本文选题：自动纤维铺放 + 线型规划　；参考：《武汉理工大学》2015年硕士论文

【摘要】：自动纤维铺放是近年来发展起来的一种新型复合材料成型技术,其综合了纤维缠绕和铺带技术两种成型工艺的优势,在大结构尺寸、大曲率、复杂边界条件等复合材料构件的自动成型当中发挥着不可替代的作用。因而越来越受到工业发达国家的重视。自动铺丝线型规划及与之对应的CAD/CAM软件的开发是自动纤维铺放的关键技术之一。铺丝线型,即复合材料纤维丝束在芯模上的排布形式,直接决定了复合材料构件的各项性能,因而铺丝线型规划的合理与否将关系到复合材料构件加工的成败。铺放过程中,铺放设备只有沿着特定的轨迹将纤维丝束铺放到芯模表面上才能够保证满足构件的性能要求。这是因为,自动铺丝中所采用的纤维丝束弹性模量大,变形能力有限,只有沿着特定的轨迹才能保证丝束不起皱、不撕裂地铺放到芯模表面上;且为了提高复合材料构件的力学性能,通常希望构件上任意一点的纤维方向能够与其应力的方向相匹配。因此,自动铺丝中的纤维铺放方向受到多方面的限制,其线型规划是一个非常复杂的计算过程,必须有一个完备的理论作为支撑。基于上述讨论,本文提出了一种多约束自动铺丝线型规划算法。考虑构件的几何形状、制品力学性能、材料加工工艺性、加工设备等因素,建立了力学约束模型、加工工艺性约束模型、铺丝靴自适应约束模型,并且将这三个模型应用于线型规划过程中。且提出了自左向右遍历型面以求解全部线型的方法。采用双向规划及线型延伸算法来求得一条完整的线型,保证了边界处的型面能够被铺上预浸料。引入重合度以衡量铺放过程中的纤维离缝和重合程度,通过线型规划过程中的覆盖性分析来生成纤维的动态裁剪和重送方案,以此保证了预浸料能够按要求覆盖整个型面。在VC++6.0开发平台上,借助OpenGL技术开发了自动铺丝CAD/CAM软件,其能够满足多种模型及不同铺放头参数的线型规划要求。良好的人机界面实现了整个线型规划过程的可视化,其运动规划处理器生成的数控加工代码为后续的自动铺丝仿真加工奠定了基础。
[Abstract]:Automatic fiber placement is a new type of composite molding technology developed in recent years. It combines the advantages of filament winding and tape laying technology, in large structure size, large curvature, Complex boundary conditions play an irreplaceable role in automatic forming of composite components. As a result, more and more attention has been paid by industrial developed countries. One of the key technologies of automatic fiber placement is the development of automatic filament-laying planning and the corresponding CAD / CAM software. The type of filament-laying, that is, the arrangement form of composite fiber bundle on the core die, directly determines the properties of composite components, so whether the planning of filament-laying is reasonable or not will be related to the success or failure of the processing of composite components. In the laying process, the laying equipment can meet the performance requirements of the components only by placing the fiber bundles on the core mold surface along a specific track. This is because the fiber bundle used in the automatic filament laying has a large elastic modulus and limited deformation ability. Only along a specific track can the tow not wrinkle or tear the floor spread onto the core mold surface. In order to improve the mechanical properties of composite members, it is usually expected that the fiber direction at any point in the composite member can match the direction of the stress. Therefore, the orientation of fiber placement in automatic filament laying is limited by many aspects, and its linear planning is a very complicated calculation process, which must be supported by a complete theory. Based on the above discussion, this paper presents a multi-constraint automatic thread laying programming algorithm. Considering the geometric shape of components, mechanical properties of products, material processing technology, processing equipment and other factors, a mechanical constraint model, a machining process constraint model, a self-adaptive constraint model of silk boots are established. These three models are applied to the linear planning process. The method of ergodic surface from left to right to solve all the lines is presented. Bidirectional programming and linear extension algorithm are used to obtain a complete line shape, which ensures that the shape surface at the boundary can be preimpregnated. The degree of coincidence is introduced to measure the degree of fiber slit and coincidence in the process of laying and laying, and the dynamic cutting and refeeding scheme of the fiber is generated through the coverage analysis in the process of linear planning, so as to ensure that the prepreg can cover the whole shape surface according to the requirements. The CAD / CAM software of automatic wire laying is developed on the platform of VC 6.0 with OpenGL technology. It can meet the requirements of various models and linear planning of different placement parameters. The good man-machine interface realizes the visualization of the whole linear planning process, and the NC machining code generated by its motion planning processor lays the foundation for the subsequent automatic wire laying simulation machining.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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