Predictive Model of Delamination in Drilling of Carbon Fiber Reinforced Plastic (CFRP) Using Response Surface Methodology

指導教授：江俊顯[[abstract]]鑽孔加工是碳纖維複合材料常見的加工方式之一，在鑽孔過程中，脫層的大小是用來評價加工品質的重要依據，孔壁周圍發生脫層現象是造成材料缺陷的最主要原因，因 而瞭解脫層發生的物理機構及預測脫層發生的影響因子顯得日益重要；因此本文以不同的進給率、主軸轉速、刀具直徑及是否有壓克力支撐等四種可能常見因素來探討這些常見加工參數對脫層的影響程度，並利用反應曲面法配合電腦軟體預測分析不同加工條件下，鑽削碳纖維複合材料時發生脫層大小之模式。實驗及分析結果顯示一般脫層常發生在鑽削材料之入口處及出口處，其中出口處的脫層較為嚴重，而鑽削加工時在碳纖維下方使用壓克力墊片支撐，可以有效減少脫層的發生。本文探討因子中以刀具直徑對脫層之影響最為顯著，其次為主軸轉速與進給率。 根據反應曲面法分析結果顯示二階預測模式比一階預測模式更能精準的預測脫層發生的大小，且誤差值低於5%。二階模式預測結果中，出口處之最佳鑽削條件進給率(A)為 16mm/min，主軸轉速(B)為1600rpm，刀具直徑(C)為6mm，配合使用壓克力墊片。本文研究結果可以做為降低碳纖維複合材料鑽孔加工脫層發生之重要參考依據。[[abstract]]Drilling operation is fundamental in the manufacturing industry especially in drilling holes of sheet metal parts. In fact, drilling laminates composites materials are significantly affected by delamination tendency when being processed under action of drilling parameters. In this paper, response surface methodology (RSM) is proposed to analysis the delamination factor at entrance and exit of the holes in the drilling process of carbon fiber-reinforced plastic (CFRP) composite laminates. Experiments were performed to investigate the delamination level with the parameters of feed rate, spindle speed and drill tool diameter during the drilling operation. And hence it is essential to select the best combination values of the drilling process parameters in order to minimize the harmful-effect for the CFRP materials. The results indicated that the data of second order predictive model of delamintion are in good agreement with the experiments’. From the analysis it is evident that among the all these parameters, drill diameter has significant influence on push down delamination. And it causes a smaller delamination factor with the acrylics back up. The best combination of the drilling process parameters at exit of the holes are feed rate = 16mm/min, spindle speed = 1600rpm, drill diameter = 6mm with the acrylics back up