周期性管柱结构声传输性能研究

RESEARCH ON ACOUSTICAL TRANSMISSION PROPERTY OF PERIODIC PIPE STRUCTURE

分析了声波在管柱中的传播机理和特性,建立了周期分布的管柱模型,依托该模型进行了声波特性研究。结果表明,对于周期性钻柱结构,结构尺寸决定了管柱的频带结构,并且这种频带结构的变化分布呈现出周期性和对称性。在一个频带周期内随着频率的增加,通带先变窄再变宽,阻带则先变宽再变窄,结构差异增大会使通带变窄,甚至出现完全的阻带。

The transmission characteristic and mechanics of acoustic wave within pipe string were analyzed.Based on the model of periodical acoustically transparent layer,the ideal drill string model was established,acoustic characteristics of model were analyzed.The results showed that the frequency band of pipe string mainly depended on the length of the drill pipe or area of the joints.The distribution of frequency spectrum exhibited periodic and symmetrical property.With the increase of frequency,the pass bands firstly narrow and then widen,and the stop bands firstly widen and then narrow in one frequency band.The pass bands narrow with the length of drill pipes increasing,and the pass bands widen with the area of the joints decreasing,and the length difference of drill pipes lead to narrowing pass bands.