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

复合材料在许多结构中都使用，因为具有很高的重量比和易于格式。复合材料通常组装并连接在一起以进行大尺寸结构。因此，组装和连接复合组件通常需要辅助加工过程，例如钻孔，观察等。当加工复合材料时，分层发生在层压层之间的粘合剂层。需要在行业加工过程中防止分层。从振动的角度来看，可以在切割过程中使用相对较小的振动负载切割硬材料，并提高机理表面的精度。然而，尚未发表有关使用振动负荷进行切割复合材料的研究。在这项研究中，提出了使用振动钻孔过程中复合材料进行分层的方法。在这种方法中，足以产生小振动载荷并使用小型振动器或超声振动器。他……更重要的是，提出的方法有望是实用的。首先，某些实验检查了所提出的方法。支持复合材料在支撑装置上，并在钻孔过程中使用小型振动器摇动。对于某些兴奋频率，工具材料，工具直径和工具旋转的条件，测量了分层的发生。激发频率是通过考虑样品的频率响应函数来确定的。测量了受到白噪声兴奋的样品的响应的功率谱密度函数。功率光谱密度函数具有峰值的频率作为兴奋频率选择。为了进行比较，一些标本是加工的，而无需振动负载。通过加工表面的表面粗糙度检查分层。钻取后，样品被钻石切割机切成孔中心。测量了加工表面的中心线平均高度粗糙度。因此，当复合材料用振动加工时，分层的发生变化较小。在最后，通过理论方法检查了实验的结果。粘合剂层被认为是阻尼成分。获得粘合剂层中的消散能，并得出了发生分层的条件。较少的