Characterization and detection of acceleration-induced cavitation in soft matters using a drop-tower-based repetitive impact system

A repetitive impact system, comprising:

• a drop tower having a moveable mass configured to move in a vertical direction with respect to the drop tower;
• a sample holder positioned in a path of travel of the moveable mass with respect to the drop tower;
• and
• a motor system configured to repeatedly lift the moveable mass, the motor system comprising:
• a motor configured to rotate;
• a rack attached to and configured to move with the moveable mass, wherein the rack has a plurality of teeth;
• and
• a pinion gear attached to the motor and positioned to periodically engage with the plurality of teeth of the rack, and wherein when the pinion gear engages with the plurality of teeth of the rack, the pinion gear is configured to lift the rack and the moveable mass up to a desired height and drop the rack and the moveable mass to impact the sample holder.

A method for detection of initial cavitation nucleation while applying repeated impacts, the method comprising:

• providing a sample holder configured to contain a soft material sample;
• positioning an accelerometer in contact with the sample holder;
• impacting the sample holder repeatedly with a moveable mass moving in a first direction;
• selecting a threshold acceleration value for the accelerometer in a second direction perpendicular to the first direction;
• and
• detecting, with the accelerometer, initial cavitation nucleation within the soft material sample by detecting an acceleration value higher than the threshold acceleration value.