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Drilling of Composite Material Using Vibration

利用振动对复合材料进行钻孔

基本信息

批准号：
08650304
负责人：
AOKI Shigeru
金额：
$ 1.54万
依托单位：
Tokyo Metropolitan College of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

Composite materials are used in many structures since there are high strong-to-weight ratio and easy formational. Composite materials are usually assembled and joined together for large size structure. Therefore, secondary machining process such as drilling, sawing etc. are often required for assembling and joining composite components. When composite materials are machined, delamination occurs at adhesive layer between laminated layers. It is required to prevent delamination during machining in industry. From view point of vibration, it is possible to cut hard materials using relatively small vibrational load during cutting and to improve precision of machined surface. However, study on cutting composite material using vibrational load has not been published.In this study, preventing method of delamination of composite material during drilling using vibration is proposed. In this method, it is enough to generate small vibrational load and to use small shaker or ultrasonic vibrator. He … More nce, the proposed method is expected to be practical.First, the proposed method is examined by some experiments. Composite material is supported onto the supporting device and shaken during drilling using a small shaker. For some conditions of excitation frequencies, tool materials, tool diameters and tool revolutions, occurrence of delamination is measured. Excitation frequencies are determined by considering frequency response function of the specimen. The power spectral density function of response of the specimen subjected to white noise excitation is measured. Frequencies at which power spectral density function has peaks are chosen as excitation frequencies. For comparison, some specimens are machined without vibrational load. Delamination is examined by surface roughness of machined surface. After drilling, the specimens are cut by a diamond cutter through center of holes. Center line average height roughness of machined surface is measured.From the experiments, it is found that surface roughness of composite material machined with vibration is less than that without vibration for many conditions for each condition. Hence, when composite materials are machined with vibration, occurrence of delamination becomes less.Finally, results of experiments are examined by a theoretical method. Adhesive layer is considered to be damping component. Dissipated energy in adhesive layer is obtained and condition where delamination occurs is derived. Less

复合材料由于具有高的强度重量比和易于成型等优点，被广泛应用于各种结构中。复合材料通常被组装和连接在一起，用于大尺寸结构。因此，复合材料构件的装配和连接往往需要钻削、锯切等二次加工工艺。复合材料在机械加工过程中，层间粘结层会发生分层。工业上要求在机械加工过程中防止分层。从振动的观点来看，可以在切削过程中使用相对较小的振动载荷来切削硬质材料，并提高加工表面的精度。然而，利用振动载荷切削复合材料的研究还没有发表，在本研究中，提出了防止复合材料在振动钻削过程中分层的方法。在这种方法中，产生小的振动载荷和使用小的振动器或超声波振动器就足够了。他 ...更多信息首先，通过实验对所提出的方法进行了验证。复合材料被支撑在支撑装置上，并在钻孔期间使用小型振动器进行振动。在一定的激励频率、刀具材料、刀具直径和刀具转速条件下，测量分层的发生。激励频率由试件的频响函数确定。测量了试样在白色噪声激励下响应的功率谱密度函数。选择功率谱密度函数具有峰值的频率作为激励频率。为了进行比较，一些试样在没有振动载荷的情况下进行加工。通过加工表面的表面粗糙度来检验分层。钻孔后，用金刚石刀具通过孔中心切割试样。测量了复合材料加工表面的中心线平均高度粗糙度，通过实验发现，复合材料振动加工的表面粗糙度在每种条件下，在许多条件下都小于无振动加工的表面粗糙度。因此，当复合材料进行振动加工时，分层的发生变得更少。最后，实验结果进行了理论分析。胶粘剂层被认为是阻尼成分。得到了胶层中的耗散能，并导出了发生分层的条件。少