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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.

AM White Paper

This paper describes ways to apply Vibrant Process Compensated Resonance Testing (PCRT) to parts produced by Additive Manufacturing Technologies.

Fan Blade White Paper

This paper describes ways to apply Vibrant Process Compensated Resonance Testing (PCRT) to Fan Blades to improve Quality and to Reduce Risk.

SX White Paper

This paper describes ways to apply Vibrant Process Compensated Resonance Testing (PCRT) to single crystal parts to verify grain orientation.

NDT Technology Readiness A P&WC Case Study

Presentation by Pratt & Whitney Canada to A4A NDT Forum describing a P&WC Case Study for application of PCRT. "P&WC was able to rapidly implement a PCRT inspection process that met the expectation of the various aviation regulatory bodies thus allowing the fleet to continue flying"

Delta TechOps Customer Case Study

PCRT helped Delta reduce failures and unscheduled engine removals while reducing costs and salvaging thousands of previously rejected blades.

Process Compensated Resonance Testing – Whole Body and Surface NDT for Ceramic Balls

Ceramic material advancements have produced many new components to meet the needs of the growing technology requirements. Traditional NDT methods (UT, ET, RT, and PT) often provide incomplete results when used to inspect these components, leading to multiple costly and time consuming inspections. Process Compensated Resonant Testing (PCRT) has been demonstrated as an excellent alternative for inspecting ceramic parts that cannot be inspected with traditional NDT. PCRT goes beyond traditional resonance testing by applying pattern recognition algorithms and process control statistics to precise resonant data. PCRT is a trained method that learns which resonance variation is acceptable, and which is unacceptable, while also monitoring in-control processes. PCRT is used for studying structural integrity and functional performance in a variety of ceramic parts including ceramic balls, seal rings, and armor plates. PCRT is a whole body inspection that detects internal defects such as [...]

Process Compensated Resonance Testing JT8D-219 1st Stage Bladea

The JT8D 1st stage turbine blade has had in-service challenges for some time. This has primarily been attributed to multiple failure mechanisms, which often intertwine to produce unscheduled engine removals, in-flight shut downs, and failures. The main contributors are intergranular attack, overtemps, thin walls, core shifts and cracking. Since most inspection techniques only detect cracking, or measure dimensions (thin wall), a significant number of “bad” blades were still escaping the inspection process. Delta engineering desired a better inspection technique to determine the serviceability of each of these conditions. PCRT provided a quick, easy method for determining the structural acceptability of the blade allowing Delta to reject only blades with defects, avoiding the costly wholesale blade replacement with new parts. This resulted in significant savings by not throwing away “good” parts, and will likely increase reliability of the JT8D engine by removing the “bad” blades.


  • 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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