In the testing of impact-echo method in pile or other structure

the signals are got by velocity or acceleration transducers .The signals include the velocity response of the observing point and the influence of transducer behavior . First of all

the velocity response of pile are simulated by the numerical simulation software FLAC-3D .Secondly

the velocity response comprising the transducer behavior are gained by signal synthesis. And a new time-frequency domain analysis method

wavelet analysis

is introduced to study the influence of transducer on the velocity response. Finally

a new suppressing method

wavelet suppressing method

for suppressing the influence of transducer is put forward. In order to validate the new suppressing method

several examples are given; and the results indicate that the new suppressing method is practicable.