Abstract:The dynamic procedure of an ideal free pile with a shock force impacting at its top is mathematically simulated by means of one-dimensional wave equation. The theoretic time history of velocity response without considering transducer at the top of pile is calculated with FEM program. The frequency-domain descriptions of the shock force and the velocity response are given out through convolution integral and Fourier transform of LTI system. According to the LTI system theory,an analysis is made on the dynamic procedure with considering transducer behavior and the frequency-domain description of velocity response is obtained. The digital frequency-domain combination of a typical transducer behavior with the velocity response of ideal free pile without considering transducer is turned back into a time history of velocity response,so that the transducer behavior can be considered through Fourier back transform. Calibrating shock duration and calculating the velocity responses from a certain transducer,the law of combination influence of shock force with transducer on the velocity response is developed and validated with examples. A new type of transform-domain suppressing method is put forward at last,so that the influence of transducer behavior within velocity response can be suppressed by means of a computation program possibly.