切削与振动联合测试诊断机床整机薄弱环节

Diagnosis of the Weak Links in the Overall Machine Based on Cutting Experiment and Vibration Experiment

通过对机床进行切削实验和振动实验,用这种联合的测试手段分析出机床整机的薄弱环节。首先,对机床进行整机模态实验分析,得到整机固有频率和振型,对其动态特性有一些初步掌握。其次,在机床进行切削实验过程中,采集记录时域下的切削力数据。通过快速傅里叶变换,在频域下对该数据进行分析,找出切削力较大时所对应的频率。最后,结合切削力测试结果和整机模态测试结果进行对比分析,找出在切削过程中切削力较大值所对应的频率恰好与整机某一阶次固有频率相重合。通过分析该阶次所对应的振型,找出整机的薄弱环节。

Cutting experiment and vibration experiment were combined to find tile weak links of the overall machine. Modal analysis of the overall machine was carried out to get the natural frequencies , vibration modes, lhe dynamic cbaraeteristics. Cutting force data ill time domain were collected and recorded during the cutting experiment. The data were analyzed in frequency domain by means of rapid Fourier transform in order to find the frequency corresponding to the larger cutting force. Finally, comparative analysis was carried out between experimental data of cutting test and modal experimental data of the overall machine. Then, the frequency corresponding to the larger value of cutting force was hmnd to be coincided with the natural frequency of a certain order. The weak links of the overall machine were flmnd by analyzing lhe corresponding vibration mode of this order.