基于声发射CFRP加工刀具磨损及孔出口损伤研究

Tool wear and hole exit damage in drilling CFRP based on acoustic emission

针对碳纤维复合材料加工过程中刀具磨损及孔出口损伤问题,监测CFRP钻削过程的声发射信号,分析不同钻削参数和不同孔数下刀具后刀面磨损、声发射信号及孔出口损伤。结果表明:在钻削过程中,转速一定时,随着进给量的增加,刀具磨损速度加快,声发射信号幅值也增大,孔出口处更容易产生撕裂与毛刺。声发射信号幅值小于1.5 V,孔出口质量较好;当幅值大于1.5 V,则孔出口产生撕裂与毛刺。刀具的磨损会引起声发射信号的变化,利用小波包分析提取刀具磨损声发射信号的频段能量特征,通过监测这些频段的能量百分比变化可有效判断刀具的磨损情况。

The acoustic emission signal of CFRP drilling process was monitored to analyze tool wear and hole exit damage.The tool flank wear,the acoustic emission signal and the hole damage were analyzed under different drilling parameters and hole numbers.The results show that the tool wear and the amplitude of the acoustic emission signal increase with the increase of feed rate during the drilling process.When the feed rate is increasing,the hole exit is more likely to produce tear and burr.When the amplitude of the acoustic emission signal is less than 1.5 V,the quality of the hole exit is good.However,when the amplitude is greater than 1.5 V,the hole exit produces tear and burr.The tool wear causes the change of the acoustic emission signal.The band energy characteristics of the acoustic emission signal of the tool wear are extracted by wavelet packet analysis.By monitoring the energy percentage can effectively determine the wear of the tool.