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Publications & Standards

Read Vibrant’s publications, white papers and ASTM Standards to keep you up-to-date on the latest with PCRT.

Characterizing Polymer O-Rings Nondestructively using Resonant Ultrasound Spectroscopy

Polymer O-rings are an essential part of many designs, including mission and safety critical systems. Currently, there are no accurate destructive tests for measuring the polymer properties of O-rings (e.g. durometer), let alone nondestructive methods. As such, it is difficult to identify substandard, nonconforming, improperly processed or counterfeit O-rings. This work combines resonant ultrasound spectroscopy (RUS) with machine learning and predictive analytics to sort O-rings based on material and durometer (multinomial classification) and to accurately estimate the mass and durometer with an ultrasonic examination that takes less than 10 seconds. Results from a population including eight materials and six durometers are presented and discussed.


  • U.S. Patent 10481104, 10718723 for Utilizing RI of in-service parts
  • U.S. Patent 9157788, 10067094 for Part evaluation system/method using both resonances and surface vibration data
  • U.S. Patent 8903675 for Acoustic system and method for NDT of a part through frequency sweeps
  • U.S. Patent 9228981 for Resonance Inspection-based surface defect system/method
  • U.S. Patent 9335300 for SAW mode-based surface defect method
  • U.S. Patent 9927403 for Resonance inspection sorting module array
  • U.S. Patent 10295510 for Part evaluation based upon system natural frequency
  • U.S. Patent 9074927 for Methods for non-destructively evaluating a joined component
  • U.S. Patent 9228980 for Non-destructive evaluation methods for aerospace components
  • U.S. Patent 10746704 for PCRT for process control

ASTM Standards

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