Experimental research on impact force of drop impacting on horizontal plate

The force of a low-speed drop impacting on the wall is tiny with a short duration. To measure the impact force precisely, an experimental rig was developed by adding a high-precision piezoelectric sensor. The measuring system was optimized based on both theoretical analysis and experimental verification, and the effect of system vibration on the transient impact force was investigated. The precise impact force can be obtained in terms of filters and other measures to eliminate the signals of the system vibration. In this approach, a double oscillator model was adopted to analyze the effect of the substrate and impact plate masses on the impacting force signal. Then the experimental frequency spectrums were compared to verify the vibration model, and the factors causing the fluctuation of force signals were determined. It is found that the vibration of the substrate and the impact plate is responsible for the fluctuation of force signal, which can be eliminated by choosing a very heavy substrate and a light impact plate combined with low-pass filter. Such an improved experimental system can measure the impact force of drops with different properties, diameters and impact velocities.