B. Materials Sensors Technologies, Inc. - NDT.net · 2011-08-02 · Materials and Sensors Technologies, Inc, 2009. ... . ``They have very little confidence in the industry-acce\൰ted
17
Historical Retrospect of the “International Symposium on the Nondestructive Characterization of Materials” B. Boro Djordjevic Materials and Sensors Technologies, Inc. WHAT CAN BE DIRECTLY AND REPRODUCIBLY MEASURED?
The Symposium series was started by Robert Green, Johns Hopkins University and Clay Ruud, Pennsylvania State University. Every meeting to date was supported by Professor Green.
Photo by J. Bart Rayniak photo
After Clay Ruud retired from Penn State University, he wanted to return to his native Spokane and ski. So he designed a house in Northwoods and built a custom kitchen so his wife Paula Mannino, second from left, could offer cooking classes.
Professor Robert Green in the CNDE office next to some of his travel acquisitions.
WHERE WE GO FROM HERE?
•Materials Characterization is more and more important but
it is confused with defects (Cracks...) and conventional NDT.
• Engineering is interested in materials properties, materials behavior and degradation.
• There are still enormous gaps in the technology for the characterization of materials.
• Common traditional materials properties practice is sample and recipe based statistics: With assumptions of the applicability to every part/product With assumptions of uniformity (absolutely false in composites…)
• The Symposium has served well in technical interchange, evolution of ideas and promotion of the science, engineering and the technology applications.
• We need to recognize that failure mechanisms are related to the
understanding of materials properties and our ability to properly characterize
materials.
NDT REQUIREMENTS PREDICTION PATH:Measure and model material damage from micro to macro to structural effects
TIME/CYCLES Failure
MICRO
MACR
OSTRU
CTURE
DAMAGE SIZE
CRACK
DAMAGE
MICRO CRA
CKS
CRACK DETECTION THRESHOLD
SAFE SER
VICE
TRANSITIONS
MATERIAL DAMAGE DIAGRAM
Incipient Damage
MULTI CRACKSINGLE CRACK THRESHOLD
Materials Characterization Domain
Issues with Structural NDT Diagnostic
Copyright Materials and Sensors Technologies, Inc, 2011
• DO WE UNDERSTAND EFFECTS OF DEFECTS?• DO WE UNDERSTAND WHAT ARE DEFECTS ?• WHAT ARE FAILURE MECHANISMS?
• If you use the same old tools without innovative methods, you’re going to make the same old discoveries.
•Doing the same thing over and over while expectingdifferent results is a definition of insanity.
Copyright Materials and Sensors Technologies, Inc, 2009
What am I testing for?
Expensive Catastrophes in HistoryTitanic ‐
$150 Million
Click to AdvanceFailure Mechanisms ?
Copyright Materials and Sensors Technologies, Inc, 2009
B‐2 Bomber Crash ‐
$1.4 Billion
Expensive Catastrophes in History
Failure Mechanisms ?
Copyright Materials and Sensors Technologies, Inc, 2009
Challenger Explosion ‐
$5.5 Billion
Expensive Catastrophes in History
Failure Mechanisms ?Copyright Materials and Sensors Technologies, Inc, 2009
Space Shuttle Columbia ‐
$13 Billion
Expensive Catastrophes in History
Failure Mechanisms ?
Copyright Materials and Sensors Technologies, Inc, 2009
Copyright Materials and Sensors Technologies, Inc, 2009
Copyright Materials and Sensors Technologies, Inc, 2009
Presenter
Presentation Notes
Accident Sequence �The NTSB calculated that the time between flight 587’s liftoff from Runway 31L until impact with the ground was 103 seconds. The flight data recorder (FDR) recorded data for about 93 seconds after liftoff and the cockpit voice recorder (CVR) continued to record information until at or about the time of the plane’s impact with the ground. Based on radar data, flight 587 took off approximately 105 seconds behind a Japan Airlines 747. The FDR indicates that flight 587 encountered two wake vortices generated by JAL flight 47. The second wake encounter occurs about 8 seconds before the end of the FDR data. For the first few seconds after the second wake encounter, the aircraft responded to flight control inputs. Both wake encounters averaged about 0.1 G lateral (side to side) movement. During the last 8 seconds of FDR data, the plane experienced three stronger lateral movements, two to the right of 0.3 and 0.4 Gs, and then one to the left of 0.3 Gs. These lateral forces corresponded in time with rudder movements. The NTSB continues to investigate the cause of the rudder movements. The FDR’s rudder data becomes unreliable about 2.5 seconds before the end of the recording, and sound spectrum analysis shows that engine sounds can be heard on the cockpit voice recorder beyond that point. The rudder and tail fin were found first in the wreckage path, followed by the engines and then by the main wreckage impact point at the intersection of Newport and 131st Street, Belle Haven, New York. Dozens of American Airlines pilots want the company to ground its fleet of Airbus A300 jets until investigators determine why Flight 587 crashed in New York City last November. The pilots say there is no way adequately to inspect the European-made planes' tails, which are made of a nonmetallic composite material. ``They have very little confidence in the industry-accepted standard of visual inspections alone,'' said Robert Sproc, an American pilot for 11 years and Miami vice chairman of the Allied Pilots Association. After the crash, which killed 265 people, the Federal Aviation Administration ordered visual inspections of the Airbus tails. The FAA has not ordered American to stop flying the planes. Airbus Industrie, the plane's French-based manufacturer, said there is no need to look for hidden damage because tests have shown that any problems that cannot be seen are not severe enough to weaken the tail. John Lauber, Airbus' vice president of safety and technical affairs, said the design and tests of the tail took into account that they would not be inspected for hidden flaws. In a statement, American Airlines said it sees no need to stop flying the Airbus. ``Nothing in the examination of the Airbus fleet, or in the tests conducted by the National Transportation Safety Board, by American Airlines or by other Airbus operators, suggests that there is a need to ground this fleet,'' the airline said. The NTSB is investigating the Nov. 12 crash of an Airbus A300-600 plane near Kennedy Airport, in the Rockaway Beach section of Queens. The tail fell off before the plane crashed, and investigators want to know why. NTSB investigators reported this month that layers of the tail had peeled away. They said they did not know whether the problem contributed to the crash or occurred after the tail hit the ground. What bothers some American pilots is that there may have been some damage that visual inspections didn't find. There are no procedures for using ultrasound or another method to look inside the composite material of the tail section. Former NTSB investigator Greg Feith said a way should be found to inspect the tail for hidden flaws. ``When they designed that airplane and designed that tail, they should have designed the ability to do an inspection,'' Feith said. ``If it's weakened in any way, that's going to fail just like any material.'' More than 70 pilots have signed onto the following statement, which is being distributed by e-mail: ``Until a definitive cause for the crash of Flight 587 can be determined, along with ways to prevent a similar occurrence, and/or a definitive test can be developed to truly check the structural integrity of the vertical stabilizers of our remaining 34 A300s, I recommend that American Airlines' fleet of A300s be grounded.'' The pilots who drafted the statement had planned to send it to American, but the company obtained a copy and responded before receiving it. American then invited some of the pilots to spend the day Thursday at American's Airbus maintenance base in Tulsa, Okla., to see how the planes are maintained and inspected. Airbus' Lauber said other examinations are unneeded. ``If damage is not visible, then we know it does not affect the strength of the material, and it will not grow during the service life of the airplane,'' he said. ``A visual inspection will be adequate to find any anomaly that would be of concern.'' �
Mechanical Properties
x
‐y
z
X=Z=Y
Copyright Materials and Sensors Technologies, Inc, 2009
MECHANICAL PROPERTIES:TIME, TEMPERATURE, DIRECTION
• We have become very sophisticated with materials and did not keep up with materials characterization.
• We need to continue this quest and impact the technology via future Symposia.
• How we go about it is to be discussed Tuesday 16:30, please contribute.
WELCOME TO Virginia Tech
SUMMARY OF SESSIONS AND EVENTS:
Sunday1800
Welcome ReceptionMondayA‐01 1330 J. DukeA‐02 1600
T. YolkenTuesdayA‐03
800
I. SolodovA‐04
1030
J. DukeA‐05 1320
R. Gr. MaevA‐06 1530
J. DukeA‐07
1630
NDCM IOC meetingWednesdayA‐08
800
B. TittmannPicnic
1730
Duck PondThursdayA‐09
800
S. KendarianA‐10 1030
R. ZoughiA‐11
1320
B. DjordjevicA‐12
1530
W. Arnold
NESC NDE TDT Face‐to‐Face MeetingWednesday, June 22, 2011,
