January 2021 | Vol. 1

ACOUSTIC EMISSION WORKING GROUP[AEWG]
Annual Newsletter of Acoustic Emission Developments and Ideas!

WELCOME NOTE FROM THE AEWG EXECUTIVECOMMITTEE!
2020 brought many challenges and uncertainties into ourlives. We recognized the importance of communication and the community engagement in these challenging
times. Using the digital platforms, we aim to increase the communication and thedissemination of Acoustic Emission-related research, publications, meetings, instrumentation and news. We are
happy to announce an annual AEWG newsletter.
We would like to thank the contributors to this first edition of AEWG digital newsletter. We will continue toincrease the communication and the collaboration among AE researchers, practitioners and manufacturers indigital platforms. Content of newsletter:
The outcomes from the first virtual AEWG meeting with over hundred participants from all over the world
Announcement of AEWG-63
Worldwide AE Research News
Data sharing platform to increase the collaboration among AE researchers
Updates on AE Books, Publications and Journal of Acoustic Emission
News from AE Manufacturers
News from AE Users
Conference and Meeting Announcements
Data sharing platform to increase the collaboration among AE researchers
The first meeting of Acoustic Emission
Working Group (AEWG) was held in
Idaho Falls, on February 8, 1968.
The first issue of Journal of Acoustic

Newsletter Designed by: Sarah Malik, Drexel University

Emission was releases in 1982.

NEWS FROM AEWG-62: 1ST VIRTUAL
AEWG MEETINGAEWG Goes Virtual!
We are passing through unprecedented times ofmodern life. To stay connected with ourcommunity and promote discussions, promotions and collaborations in thesechallenging times, we hosted AEWG-62 on a virtual platform. We had thirty one
asynchronous technicalpresentations and three live sessions including two panel
discussions and AEWG business meeting.

31 AsynchronousTechnical Sessions&
3 Live Sessions

Panel 1: The use and challenges of
AE for online monitoring for essential systems led by Dr. Antonios Kontsos
Panel 2: Status of AE Standards
led by Dr. Valery Godinez

First Page of Zoom of AEWG 62

Further Information
AEWG News at http://aewg.org/
IIIAE News at http://iiiae.org/

UPDATES FROM AEWG-62
AEWG Business Meeting
Led by Didem Ozevin

We welcomed new AEWG members: Dr. Obdulia Ley, Dr. Hossain
Saboonchi, Dr. Miguel Gonzalez Nunez, Dr. Behnoush Golchinfar.
Four AEWG membership applications were submitted: Dr.
Mohammed Hameed Sabhan Al-Tofan, Dr. Jason Ongpeng, Hermann
Schubert and Angela Angulo.
There was no Adrian Pollock StudentAward winner in AEWG-62.
Dr. David Kosnik was appointed as the AEWG Archivist. The AEWG
acknowledged all the contributions of Tom Drouillar over the years as
the AEWG Archivist.
The Fellow Award in AEWG Bylaws was amended to reduce five yearsof active membership to be eligible.
The cash award for Adrian Pollock Student Award was increased to$600.
A new Google G-suite was set for AEWG as a way to store AEWG
documents in a digital platform and assist the AEWG organizers withemails, registration and web-site designs.

UpdatesUPDATES FROM AEWG-62
Panel 1 Summary
The Use and Challenges of AE for Online Monitoring of Essential
Systems Led by Antonios Kontsos

To kickoff discussions during this first ever virtual AEWG meeting, the
AEWG Executive Committee hosted a panel on “The Use and challengesof AE for online monitoring of essential systems”. The discussion was
led by Dr. Antonios Kontsos, Associate Professor in the Department of
Mechanical Engineering & Mechanics at Drexel University and current
Secretary of the AEWG Executive Committee. After defining what realtime/online monitoring is across different industries and using several
enabling components, several critical infrastructures were mentioned
to highlight the importance for such monitoring operations.
Commercially available tools for sensing, communication, storage anduser interfaces were mentioned. In addition, the major challenges
typically found when attempting to implement such real time
monitoring solutions were discussed. Based on this context provided,
the particular challenges to adopt AE for fully autonomous services
were presented followed by a brief listing of the items that the AEWG
community could address in the future including the development ofalternative AE sensing technologies, the standardization of data
formats, the development of new smarter processing algorithms andmore. The discussion among the virtual participants during the panel
and the responses to the survey that followed, validated the interest in
this area and provided feedback on future AEWG discussion topics.

UpdatesUPDATES FROM AEWG-62
Panel 2 Summary
Status of AE Standards
Led by Valery Godinez and Richard Gostautas

Mr. Richard Gostautas prepared a presentation on the subject of ASTM
AE standards, which are under the jurisdiction of ASTM Subcommittee
E07.04, which has 60 members. Dr. Godinez discussed potential new
standards for AE applications for which guidelines do not exist, and how
an Ad Hoc task force within AEWG could be established to further
investigate where new standards are needed. He provided an overview
of the 3 different categories for ASTM standards for AE Sensors &System Characterization and Verification. He also presented standards
for the different Industry Sectors: Building and Construction, Industry
Sector, Metals, Pressure Vessels/Piping, Composites. The panel outputs
are the followings.
Communication between ISO and ASTM regarding AE standards canbe improved.
Dr. Miguel Gonzalez is participating in ISO and looking for volunteers
to become members of the US AE expert group in ISO.
There are several articles in ASME BPV Section V and Section X
related to AE examination. Dr. Godinez invite people to join the
ASME BPV Section V Working Group AE of which he is the current
Chairman.
It is recommended to develop acceptance criteria in AE standards
considering amplitude-distance correction. It is noted that theexperience of the AE practitioner plays a big part in the pass/failcriteria using established codes.
The collaboration between academics and practitioners to develop
standards is emphasized.
AEWG participants are encouraged to join ASTM, ASME, ISO AE
committees.

UpdatesAEWG-63
SEPTEMBER 13-15, 2021
HOUSTON, TX
We are pleased to announce that AEWG-63 will be hosted by
Stress Engineering in Houston, Texas. The meeting chair will be
Napoleon Douglas.
The tentative schedule is as follows:
September 13,
2021(Monday) – Primer on Acoustic Emission in Oil and Gas Industry at AM,
Welcomereception & Social at PM
September 14,
2021(Tuesday) – Technical presentations, panel discussions, session for vendor
presentations, dinner at PM
September 15,
2021(Wednesday) - Technical presentations, panel discussions, AEWG businessmeeting
ending by 5:00pm, tour

We aim to have an in-person AEWG-63 meeting. We will update you once welearn more about the progress of pandemic.

Thank you toStress Engineeringfor Hosting!

WORLDWIDE AE
RESEARCH UPDATESBRIAN WISNER, PHD
Assistant Professor
Mechanical Behavior of Materials Group
Mechanical Engineering Department
Ohio University
t: (740)566-0136 | e: bwisner@ohio.edu|
w:https://people.ohio.edu/bwisner/index.html

The Mechanical Behavior of Materials Group (MBMG) uses Acoustic Emission (AE)combined with other Nondestructive Evaluation (NDE) Methods to understandmaterial response to external loads.
Current work is being done to understand the damage evolution of coalparticle reinforced polymers subjected to tensile and bending loads. Other work
is focused on using AE to detect the onset of fatigue cracking for both Navyand Airforce applications. MBMG is working with the Airforce Research Lab Turbine
Engine Fatigue Facility on ways to monitor turbine component life. In our current work
we are investigating thin Ti64 materials subjected tobending fatigue to identify the onset of fatigue crack growth. A single laser
vibrometer sensor is being used with a combination of frequency filtering tomonitor both AE activity and Vibrational Resonance. Further, Machine Learningalgorithms are being explored to reliably identify the onset of crack growthf .
feand subsequently predict the remaining life
life.

Work flow process for extraction of AE data froma Laser Vibrometer Setup

Research SpotlightWORLDWIDE AE
RESEARCH UPDATESPROF. MARKUS SAUSEUNIVERSITY OF AUGSBURG
E: MARKUS.SAUSE@UNI-A.DE

Research Spotlight

SINAN KALAFATBCMTEC
E: KALAFAT@BCMTEC.COM

Machining of fiber reinforced composites remains a challenging process at the end of
the value chain. Malfunctions of machinery and bad surface quality cause a tremendous loss ofvalue and need to be reduced to increase competitiveness in lightweight applications. Monitoringof machining steps can be carried out by many different techniques and strategies all with theirunique benefits and drawbacks. These provide information about machining hours, wear statusof the tool, potential malfunctions of the system and can estimate the quality of the machining
process. The team at University of Augsburg recently presented an approach to fuse different
sensing systems on the hard- and software side to combine the information of different systems
that provide a consolidated basis for the analysis of the machine status, tool status and machining
quality.
To this end results from a sensor fusion approach to measure acoustic information during themachining was published and a software framework that was developed to provide a
blueprint for real-time capable solution for feedback control was established together withthe company BCMtec.

Flow Chart ofAcoustic Monitoring
Methods Hardware
Fusion Steps for
Machining of Fiber
Reinforced Materials

WORLDWIDE AE
RESEARCH UPDATESJapanese Society for Non-Destructive Inspection isdeveloping the standard for AE
testing of Type 2 composite cylinders for hydrogen
refueling stations
Yoshihiro Mizutani
Associate Professor, Tokyo Institute of Technology
Director, The Japanese Society for Non-Destructive Inspection

Fuel cell vehicles (FCVs) are attracting attention as a means of reducing carbon
dioxide emissions. In Japan, FCVs are now manufactured by Toyota and Honda. As
of July, 2020, 131 hydrogen stations for FCV currently exist in Japan. The Japanese government
plans to increase the number of stations to 320 by 2025 and to 900 by 2030. An FCV is filledwith hydrogen from an accumulator (containing pressure cylinders) via a pre-cooler anddispenser at a hydrogen station. Most accumulators in Japan are now Type 1 or Type 3cylinders. Type 1 cylinders are made completely from low-alloy steel, and Type 3 arecomposed of composite cylinders constructed from thin aluminum liners and carbon fiber
reinforced plastic (CFRP). The surface of a Type 3 aluminum liner is fully wrapped with
CFRP. In recent years, Type 2 cylinders have begun attracting attention, as thesevessels are lighter than Type 1 and have a longer life cycle than Type 3 cylinders. A Type 2
composite cylinder is a low-alloy steel cylinder with a CFRP overwrap in the hoop direction.
The dominant failure for Type 2 composite cylinders is assumed to be the fatigue of the lowalloy steel liner, and inspecting the fatigue during service is required. To keep the inside of thecylinder clean, inspection from the outer surface rather than open
inspection is required. Therefore, the AE test is gaining attention for its ability to detect fatigue
cracks in low-alloy steel liners of Type 2 cylinders. The Type 2 cylinder is designed to ensurethat the stress generated in the liner remains below the fatigue limit, and even if fatigue cracks
do occur in the liner, a long time is required for them to penetrate. Therefore, we plan todetect fatigue cracks by conducting AE testing during the periodic self-inspection of cylinders.
The Japanese Society for Non-Destructive Inspection (JSNDI) publishes a society standard
called the Non-Destructive Inspection Standard (NDIS). Six standards are already included in
NDIS for AE testing, but the new standard will be the first standard for composite cylinders. AE
testing and analysis, which will yield the back data for the standard, have nearly been completeda part of a national project. The committee for the standard will be set up in
April, 2021 and will publish the standard within the next few years.

Research SpotlightWORLDWIDE AE
RESEARCH UPDATESRail Crack Monitoring using Acoustic Emission

Research Spotlight

AE Research Overview
DAN LIASSOCIATE PROFESSOR,SCHOOL OF CIVIL ENGINEERINGHEFEI UNIVERSITY OF TECHNOLOGY, HEFEI 23009, CHINA

Fatigue cracks are one primary type of rail defects
that would result in operational downtime and catastrophic
failures. Rail crack monitoring aims to identify fatigue cracks inadvance allowing timely repair to be carried out to ensure a safe
and smooth operation of the railway system. Acoustic emission(AE) monitoring of rail cracks in the field typically with complex
cracking conditions, high noise, and mass data was investigated. A
novel crack identification index based on Tsallis\synchrosqueezed wavelet entropy (TSWE) was first developed,
where synchrosqueezed wavelet transform (SWT) was
introduced to explore the time-frequency characteristics of AE
waves and Tsallis entropy was adopted to quantify the local
variation of wavelet coefficients more accurately. Field tests werecarried out at an incipient rail crack with trains running at
operating speeds. Time-TSWE efficiently detected and locatedthe crack by extracting the crack-related transients in AE waves.
Furthermore, the mechanisms of AE waves, including noise,
impact, and crack propagation, were explored through filed tests
and laboratory fatigue tests. AE waves indued by different
mechanisms were found to show various patterns of energy
distribution in the time-frequency domain. A multi-branch
convolutional neural network (CNN) model was brought forward
to automatically classify the three types of AE waves by taking
into account their SWT plots in various time-frequency scales.
The proposed rail crack monitoring method is able to detect not
only surface cracks, where both impact-induced and crack
propagation-induced AE waves would be identified, but alsointernal cracks where only crack propagation-induced AE waves
would be captured.

Flowchart of AE-Based Rail
MonitoringAE DATA REPOSITORY

Share & Access AE
Group Data!

Create an account: https://figshare.com/
Request access: https://bit.ly/2XFROJx
Wait 3-5 days for access approval
Log in to Figshare and accept invite
Start uploading your data (any file accepted) with respective testing details(examples in Figshare titled 'Monotonic Testing' and 'Compact Tension
Fatigue Testing with AE')

UPDATES ON AE
PUBLICATIONS, BOOKS AND
JOURNAL OF AE
The number of AE publications
show an increasing trend inrecent years according to theanalysis of the Web of
Science. Most of the papers are
published by researchers in theUSA, China,
England, Japan, Germany,
France, Russia and India. The AE
papers are typicallypublished at materials scienceand mechanics related journals.

Journal of Acoustic Emission is an international journal designed to be of broad interestand use to both researcher and practitioner of acoustic emission. It was first publishedin 1982 and volume 37 was just published in 2020. It has published and continues toseek original contributions of all aspects of research and significant engineering
advances in the sciences and applications of acoustic emission. The journal has also
published reviews, the papers presented at meetings, and technical notes. All thevolumes are available for free download at aewg.org. All the articles are also available
from ndt.net site, which can be located by putting keywords in Google. The latest
volume 37 includes a tutorial article by Alan Beattie on source localization. Volume 37
also includes selected articles from a Latin American conference, E-GLEA10. These weretranslated by the authors into English, except one paper is in Spanish (on the history of
AE in Argentina). This gives a glimpse of AE activities in Latin countries from twocontinents. The current editors are Marvin Hamstad and Gerd Manthei.
A new AE textbook is in preparation led by Dr. Ronnie Miller and Dr. Joseph Rose. The
first volume will have state-of-the-art topics including AE sources, wave propagation,
finite element modeling, machine learning methods, instrumentation and software,
source localization and standard applications. The second volume will include cuttingedge AE applications.

Publications

NEWS FROM AE
MANUFACTURERS
MISTRAS’ line of wireless systems offers users
complete Acoustic Emission (AE) testing and monitoring
solutions in portable devices, reducing the need forbulky equipment and cabling. Wireless AE systems
provide users with improved mobility, while retaining fullAE testing capabilities. A prime example of this productline is the 4-channel microSHM. MISTRAS have been
improving the capabilities of this system by adding
features such as (below). These features make themicroSHM a true IoT AE device.
MISTRAS will demonstrate the new version of thesystem together with other exciting new AE products at
AEWG 63 in Houston, TX.

SOUNDWEL TECHNOLOGY CO

Technology

Weather-Proof Packaging
Inertial Measurement Unit
Multiple Unit Time Synchronization
Power Management
Built- in Cybersecurity
Software Remote Updates
Activation Control Software
Cloud Management
Monitoring Web Portal

NEWS FROM AE
MANUFACTURERS

Technology

nAExtor - next generation acoustic emission analysis software
The nAExtor software was developed by the Bavarian Consulting &Measurement Technologies GmbH to set a new a new standard in acoustic
emission analysis. It offers a range of useful tools for processing acoustic
emission data, based on state-of-the-art analysis techniques. nAExtor mainfeatures include:
Native import of formats from different devices or industry standards (e.g. DTA/TDA/WFS,
PRIDB/TRADB, ASCII)
Visualization of relationships in the datasets.
Calculation of time-frequency representations.
Localization of acoustic emission sources with classical methods or with neural networks.
Supervised and unsupervised pattern recognition with artificial intelligence methods.
Calculation of damage onset values.
Evaluation of component condition based on cyclic criteria (Felicity ratio, Shelby ratio, ...).

The nAExtor software package can be downloaded athttps://en.bcmtec.com/naextor and is free to use after registration.

NEWS FROM AE
MANUFACTURERS

Technology

Vallen System GmbH released the new spotWave device, a single channel AEmeasurement unit. The spotWave device is robust, portable and can be controlled by alaptop, tablet PC, smartphone or IoT device. It is a fully featured AE measurement device
compliant with standard EN 13477‑1 for acquiring and processing AE feature data andwaveforms.
Measurement data is stored using the standard Vallen file format: pridb and tradb. Data
can be analyzed using the Vallen AE-Suite Software data analysis
tool chain.
The spotWave device features a coupling check transmitter (CCT) that enables a
reliable AE-sensor coupling verification and can be used for measuring the
speed of sound in a structure.
For mobile devices with an Android OS a Vallen data acquisition APP is available.
Typical applications are leakage detection at valves and pipelines, hot spot monitoring ofstructures and machines, AE baseline evaluation, wave propagation measurements andresearch.

NEWS FROM AE
MANUFACTURERS

Technology

The new Vallen Systeme linWave and conditionWave devices are dual channel AEmeasurement units in a compact IP67 housing. They can be connected to a local network(LAN) via Ethernet, are powered via PoE (“Power over Ethernet”) and can be deployed asa distributed measurement system. They are designed as a Linux based, customizable
IoT edge device for AE-based condition monitoring tasks. Moving computations andintelligence further to the edge device reduces the data transfer volume
tremendously. By extracting and transferring only results of an inference, thedata rate can be reduced from up to 40 MB/s to less than 1 MB/s (seefigure below).
In its simplest form the device canbe used as a signal recorder of conditioned sensor data (use case C).
The task of feature extraction and data analysis is outsourced
to a central server. In more specialized cases a customized feature
extraction using the VAMP plugins architecture can be
integrated on the device (use case B). In applications thatce is rundemand a high degree of integration the feature extraction and inference
on the device (use case A).

NEWS FROM AE
USERSMISTRAS recently completed a project consisted in the deployment andcommissioning of AE monitoring systems and sensors on three bridges acrossthe state. This 9-month duration project saw two contracts being executed, one
to establish monitoring for the Varina-Enon bridge in Hopewell, VA and a second
contract to monitor the Lord Delaware and Eltham bridges in West Point, VA.
This is the first time a levelized design is implemented with three different levelsof detail for the localization of potential damage in different components. A totalof 751 AE sensors were deployed
across the three bridges:
Eltham and Lord Delaware Bridges: Monitoring of Concrete box Girders
280 DaisAE nodes, 8 base stations, 28 PowerHubs, 282 AE sensors
Varina Enon Bridge - Monitoring Concrete box Girders, Cable stays andPylons
18 Sensor Highway III, 2 Samos Express 64, 2 Samos Express 96, 469
acoustic emission sensors
This hefty project of installing the systems and sensors required several
MISTRAS teams to come together.
The large number of systems, sensors, and other hardware required several
MISTRAS teams such as Field Services, Infrastructure Subject Matter Experts
and AE specialist to come together under the leadership of the Asset Monitoring
Group to successfully complete the project This important work will help toensure safety for the more than 70,000 people that cross these bridges daily, viaa state-of-the-art monitoring web application that provides 24/7 coverage of thesethree critical assets.

AE SHM Application

CONFERENCE AND MEETINGS ON AE

AEWG Executive Committee is organizing a
mini-symposium on Acoustic Emission
Monitoring of Civil Infrastructure at SHMII-10.
Join us there virtually: SHMII-10

CONTACT AEWG
Contact AEWG if you have any comments, questions
and news to share in next issue via email
executive_committee@aewg-us.org