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 a 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 processing 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 carried out. In the paper a sensor of impulsive force and pressure with one-point processing of the strain inside the bar is presented, in which the incident wave as well as the first reflected one, generated by the input function are utilised. 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 non-superposition of these pulses is the condition of the sensor functioning correctly. The way to use the sensor in a transformation reconstruction method of impact force waveform, 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 also the improved processing accuracy.