脉冲激光线源热弹激励的圆柱表面波声场

将脉冲激光线源的热弹激励等效为一横 (S)波源的切变效应 ,导出了光激圆柱声场的积分表达式 ,采用留数理论进一步得出了圆柱表面Rayleigh波声场的表达式 ,用数值求导和快速傅立叶变换 (FFT)技术数值计算了铝圆柱Rayleigh波的瞬态位移波形 .计算结果表明 ,圆柱Rayleigh波在传播距离较小时 ,与平界面Rayleigh波相似 ,随传播距离的增加 ,由于频散加剧 ,Rayleigh波形状、相位逐渐发生变化 .

Acoustic Field of Cylindrical Surface Waves Generated Thermoelastically by a Pulsed Laser Line Source

Considering the thermoelastic excitation of a pulsed laser line source impacting on the generatrix of a cylinder as a shear effect,the integral representation of the acoustic field is derived.The acoustic field of cylindrical Rayleigh wave is presented by using the residue theory. Applying the numerical derivation and the fast Fourier transform (FFT) technique,the transient displacement waveforms are calculated.The results show that the character of cylindrical Rayleigh wave is similar to that of Rayleigh of propagating along the flat surface when the propagating distance is very short,and with the increasing propagating distance,the shape and the phase of cylindrical Rayleigh wave change gradually because of the dispersive effect.