Research On Surface Detection, Extension And Offset In Designing Die-Surface Of Composite Material Mould

Due to superior material performance such as specific strength, specific modulus, manufacturability,heat resistance, corrosion resistance and fatigue resistance, composite material is widely used inaircraft manufacturing. Composite mould, as an important part of the aircraft process equipment, is ofgreat significance to promote the advent of aircraft with excellent performance. In the process ofdesigning composite mold, the design of the template is complex and requires a lot of time. Toimprove the design efficiency and quality of the composite material die template effectively, on thebasis of analysis the template design process in detail, the template design process is divided intothree major stages: surface detection and reparation, surface extension and surface offset, and carrieson detailed study of the three stages. The main research results and research methods are as follows:Surface defect detection and reparation. The types of defects and their possible causes insurface are analyzed in detail. The detection and reparation methods of those defects which areappearing frequently in the engineering practice are proposed. These methods can detect the commondefects in the surface effectively and the results can meet the subsequent designing of template. Formost surfaces with complete topology, we are able to get accurate result.Selection of processing parameters. Describe the influence of geometrical characteristics on theselection of cutter diameter and machining center in detail. On this basis, we put the methods ofselection cutter diameter and machining center forward. The methods can provide certain reference.Surface extension. In combination with the methods the designers used when it is unable to getextension, surface extension method is proposed. Compared with the original function in CATIA, thenew method can solve the problem of crevice and self-intersection which appears in points withdiscontinuity of first order. For those boundaries that can not extend, we can use the function of fillinginstead. The results not only can meet the requirements of tangent continuous but also can improvethe efficiency of extension.Surface offset. Because of the complexity of the surface, it is usually very difficult to use thefunction provided by the CAD software to implement offset. Therefore surface offset method basedon the algorithm of discrete point offset is proposed. The method can solve the problem ofself-intersection occurred when using the original function provided by CATIA, and at the same timecan control the precision of offset surface. The method improves efficiency and quality of offset.