A modified impulsive force and pressure sensor intended for waveform reconstruction purposes

The correction of the effect of dispersion on the accuracy of processing in the Hopkinson bar type mechanical transducer enables extension of its application in measurements of impulsive force and pressure of short duration onto the dispersive operating range. In the experimental methods of correction, two-point measurement of the strain inside the bar is usually applied. This way, the dispersive characteristic of the bar is determined and also the process of reconstructing waveforms is performed. In the paper, a sensor of impulsive force and pressure with one-point measurement of the strain inside the bar is presented, in which the incident wave and the first reflected one, generated by the input function, are utilized. Temporal restrictions of the input function and spatial restrictions of mounting strain gauges on the bar, preventing the superposition of the incident and the first reflected pulses in the strain gauges, are given. The nonsuperposition of these pulses is the condition of the sensor functioning correctly. The method of using the sensor for reconstruction of impulsive mechanical quantities, based on the frequency-domain deconvolution, is demonstrated. The advantage of the described sensor is the reduction in the complexity of the amplification circuit and the output signal processing circuit and thus an easier achievement of the required processing accuracy