Waveform reconstruction of impact force using a frequency domain technique and one-point strain measurement

ABSTRACT: In the paper a transformational impact force reconstruction method is presented, which features a one-point strain measurement in a mechanical transducer. To determine the spectral transmittance of a section of the mechanical transducer necessary in the reconstruction process, strain waves propagating in the transducer are used: the incident, and the first reflected one, created by the impact. Restrictions concerning the impact duration as well as the strain gauge localization on the mechanical transducer are given, which assure the non interference of the above mentioned waves in the strain gauges. The reconstruction results of impact force waveforms generated during impacts of steel spheres in the front face of a steel bar are presented. The consistency of the obtained reconstruction results with the Hertz Impact Theory with respect to the duration and amplitude of the impact force was evaluated.