摘要
对于变长度钻柱振动的实验模态分析中,在不同激励点所获得的频率响应特性不一样,个别点差异甚至非常大,实验数据存在以下问题:其一,个别测点存在频率缺失的情况;其二,有些测点得到的频率成分会集中在某个小频域范围内波动。针对以上实验模态数据存在的问题,提出了一种数据修正的算法,并编制了相应程序。通过在同一钻柱上调整传感器分布、选用不同材质锤头激励等方法分别做实验,获取了四组模态数据,使用本修正算法处理得到的钻柱固有频率一致性很好。应用有限元方法得到的钻柱的计算模态结果与实验模态结果也十分吻合。实验模态数据修正算法能较好地解决实验中被测对象固有频率的判断与修正问题。
In the experimental modal analysis of variable length drill string vibration, the frequency-responsecharacteristic of one driving point is different from others, sometimes, even very large individual differences. Theexperimental data usually has the following problems firstly, sometimes experimental data have frequency loss;secondly, frequency data may be concentrated in a small frequency range. In view of the above problems of experi-mental modal data, this paper proposes a data correction algorithm, and the corresponding program. We have ob-tained four sets of experimental modal data from the same drill string by adjusting the sensor distribution and selec-ting different material hammer. After the data processing by the correction algorithm, the consistency of the naturalfrequency of drill stem is satisfactory, and moreover, the result of computational modal analysis is consistent withthat of experimental modal analysis. This algorithm can preferably judge and correct experimental modal frequencies.
出处
《科学技术与工程》
北大核心
2014年第26期136-143,共8页
Science Technology and Engineering
基金
国家自然科学基金项目(41340048)资助
关键词
钻柱
振动
实验模态分析
固有频率
数据处理
drill string vibration
the experimental modal analysis
natural frequency
data processing
