摘要
航行舰船在海底岩土层中引起的弹性波被称为舰船地震波,主要由舰船低频辐射噪声引起,可用于识别舰船目标。将舰船地震波简化为液固多层半无限空间低频点声源引起的地震波动问题,基于波数积分方法,通过FFP数值积分得到了海底表面声压、位移和加速度的频率特性曲线,分析了不同浅海环境对点声源海底地震波的波动特征的影响。结果表明:软质海底竖直方向加速度具有明显的低频通过特征,点声源海底地震波频域特征具有方向性;接收横距、岩土层吸收衰减系数和软硬程度、水深、沉积层厚度等均对点声源海底地震波的波动特征具有影响。
The elastic wave in seabed caused by the low frequency noise of sailing vessel is the so-called ship caused seismic wave that can be used to identify ship target. The ship caused seismic wave is simplified to the seismic wave generated by a low frequency point sound source in a liquid-solid multi-layered semi-space in this paper. Based on the wave-number integration technique, the characteristic curves of acoustic pressure, displacement and acceleration on the surface of seabed varied with frequency are obtained by FFP numerical evaluation technique. The influences of various shallow water circumstances on the characteristics of the seismic wave in seabed are discussed. According to the calculation results, the characteristic of the vertical acceleration in soft seabed is dominant in low frequency band and differs from the horizontal acceleration. The characteristics of the seismic wave in seabed are apparently influenced by receiver distance, attenuation and stiffness of sediment, water depth and sediment thickness.
出处
《声学技术》
CSCD
2009年第5期596-600,共5页
Technical Acoustics
基金
国防预研项目(51303030501)
海军工程大学自然科学基金项目
关键词
浅海
点声源
地震波
声压
位移
加速度
shallow-water
point sound source
seismic wave
acoustic pressure
displacement
acceleration
