Publications & Standards

Detecting Substandard, Nonconforming, Improperly Processed and Counterfeit Materiel

2020

This report presents the motivation, background, methods and results of a Small Business Technology Transfer (STTR) project that developed and demonstrated production-level approaches for using Process Compensated Resonance Testing (PCRT) to detect counterfeit, substandard, nonconforming, and improperly processed materiel for the Defense Logistics Agency (DLA)

Characterizing Polymer O-Rings Nondestructively using Resonant Ultrasound Spectroscopy

2019

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.

Process Compensated Resonance Testing for Detection of Counterfeit, Substandard, Nonconforming, and Improperly Processed Materiel

2017

This report presents the motivation, background, methods and results of a Phase I STTR project that demonstrated the feasibility of using Process Compensated Resonance Testing (PCRT) to detect counterfeit, substandard, nonconforming, and improperly processed materiel for the Defense Logistics Agency (DLA).

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

2012

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 [...]

Ceramic Bearing Non-Destructive Evaluation Round Robin Evaluation Final Report

2012

The purpose of this project was to evaluate Process Compensated Resonance Testing (PCRT) as a nondestructive evaluation method for ceramic balls. PCRT uses measured resonant frequencies of parts to detect surface and internal flaws. For ceramic balls, internal defects and bulk material property variations are detected by measuring shifts of resonant peaks to lower or higher frequencies. Surface defects are detected by measuring degeneracy in surface acoustic waves. A PCRT inspection detects both internal and external defects in a single sweep, and returns an automated pass/fail result.

Hybrid Bearings Non Destructive Evaluation (NDE)

2011

Report summarizing Vibrant’s work to optimize the PCRT methods for detection of bulk material, and surface defects on SiN balls, and to create an Automated Ball Testing System.

A More Comprehensive NDE: PCRT for Ceramic Components

2010

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 [...]

Nondestructive Evaluation of Hybrid Bearing Ceramic Rollers Using Process Compensated Resonant Testing (PCRT)

2009

We have used Process Compensated Resonant Testing (PCRT) for studying structural integrity and functional performance of ceramic balls used in various auxiliary power units (APUs), propulsion engines, and defense and space missiles. The results show that PCRT is successful in sorting acceptable parts from parts with defects such as micro-structural changes, C-cracks, and scuffs. However, PCRT suffers from limitations, generally not determining the type, size or location of the anomaly. The pursuit of improvements to PCRT is an on-going process.

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