AIAA Non Deterministic
Approaches (NDA)
Proposal to create the
AIAA NDA Technical Committee
to
AIAA New Initiatives Subcommittee
9 January 2007
Prepared by Ben Thacker, Chair NDA Working Group, [email protected], 210/522-3896
Need for an
NDA Technical Committee
• NDA Working Group in active existence since
2004
– Over 30 members
– Operating according to TC guidelines
– 7 successful NDA forums, 1 successful NDA
conference
• Non-deterministic or probabilistic methods
now recognized in other societies
– SAE, ASME, ASCE, SEM, and ASQ
• NDA Conference requires TC-level support to
ensure enduring stream of high quality
leadership
2
What is NDA?
• Non-Deterministic Approaches are methods,
philosophies and approaches that seek to
address the effect of inherent and systematic
uncertainties in engineered systems.
• NDA is rapidly gaining ground as preferred
methods for analysis and design with
potentially high payoffs (cost, safety, etc.) in
aeronautical, aerospace, and other many
other related applications.
• NDA is currently part of the Structures TC
3
AIAA NDA – When, Why and How?
• 1st NDA Forum at 40th SDM in 1999 (St
Louis, MO)
• Bring together NDA related work
throughout the aerospace community
• Expose critical NDA issues
• Provide direction for future NDA
research
4
Background
• Successfully conducted 7 consecutive NDA
Forums (’99-’05) and one full conference (’06)
• NDA Conference approved in 2006
– Called the 8th NDA Conference to reflect our 7
previous forums
• 9th NDA Conference planned for 2007 in Waikiki,
Hawaii
– 52 accepted abstracts organized into 9 sessions
5
NDA-WG Scope
• The NDA Working Group supports AIAA
technical activities that advance the
relevant art, science and cross-cutting
technologies required for the successful
application of non-deterministic
approaches to aerospace systems.
6
NDA Working Group
Goals
1. Organize NDA Conference in support of the SDM
2. Ensure quality leadership for NDA Conference
3. Serve as the focal point for NDA technologies in
AIAA
4. Coordinate AIAA activities on NDA with other
organizations
5. Coordinate NDA activities with other AIAA
technical committees
6. Transfer NDA technology to AIAA membership
7
NDA-WG Leadership
•
•
•
•
Chair – Ben Thacker (rotate out 4/07)
Vice Chair – Chris Pettit (rotate in 4/07)
Secretary – Jason Pepin
Liaisons
–
–
–
–
–
–
–
MDO – Romero
ASA – Wallace
ASCE – Mahadevan
Structures TC – Hilton
ASME – Pepin/Romero
SAE – Ghiocel
Adaptive Structures TC – Chamis
8
NDA Conference Leadership
Year
General Chair
Technical Chair
2008, TBD
Sankaran Mahadevan
TBD
2007, Hawaii
Mike Enright
Sankaran Mahadevan
2006, Newport
Chris Pettit
Mike Enright
2005, Austin
Levon Minnetyan
Chris Pettit
2004, Palm Springs
Christos Chamis
Levon Minnetyan
2003, Norfolk
Christos Chamis
Levon Minnetyan
2002, Denver
Christos Chamis
Levon Minnetyan
2001, Seattle
Suren Singhal
Christos Chamis
2000, Atlanta
Suren Singhal
Christos Chamis
1999, St Louis
Suren Singhal
Christos Chamis
9
Sustained Performance of the
NDA Conference
70
62
60
No. of Accepted Papers
52
58
56
54
52
50
40
37
36
34
30
20
10
0
1999
2000
2001
2002
2003
2004
2005
2006
2007
Year
10
2004 NDA Forum Session Titles
•
•
•
•
•
•
•
•
•
Sampling Methods
Code Verification
Response Surface Methods
Model Validation
Dynamic Systems
Flight Applications
Materials and Design Safety Factors
Reliability-Based Design Optimization
Fatigue and Fracture
11
Current Roster – 31 Members
12
NDA-WG Makeup
14
13
Number of Members
12
10
10
8
6
6
4
2
2
0
Gov
Aca
Ind
Org
Category
13
NDA-WG Bulletin Board
14
Why Create an NDA TC?
–
–
–
–
–
–
Structures
Materials
Structural Dynamics
MDO
Survivability
Adaptive Structures
Number of Papers at SDM NDA Forum
70
Number of Papers
• Growing interest
• “Place at the table”
• Natural evolution of NDA
activities in AIAA
• As a technology, NDA is
different from yet integral
to other key SDM TC’s:
60
50
40
30
20
10
0
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
Year
NDA serves a unique purpose
15
Support
• Betty Guillie emailed proposal to all
AIAA TC chairs on 12/5/2006
Summary of Responses
TC
For
Ground Test

Space Operations and Support

Solid Rockets

Management

Survivability

Meshing, Visualization, and Computational Environments

Aircraft Operations

Balloons

Fluid Dynamics
Structures

Against
Undecided


16
Support, cont’d
• Mark Melanson, Ground Test TC
– No objections or known overlap
• Mike Mattis, Space Operations and
Support
– The SOSTC has no scope issues and
believes that Non-Deterministic Approaches
would be a good addition to the Technical
Committees
17
Support, cont’d
• I-Shih, Solid Rockets
– There is no objection from Solid Rockets
Technical Committee to creating a new
NDA Technical Committee
• J. Stephen Rottler, Management
– There is no overlap between the proposed
NDA TC and the TCM
• Ron Dexter, Survivability
– I reviewed your proposal and do not see
any conflicts or overlap
18
Support, cont’d
• John Chawner, Meshing, Visualization,
and Computational Environments
– MVCE - in the persons of John Chawner
(chair) and John Dannenhoffer (vice chair)
is OK with formation of the NDA TC
• Brian Baxley, Aircraft Operations
– …there does not appear to be any scope
overlap of the proposed TC with the
Aircraft Operations TC.
19
Support, cont’d
•
Henry Cathey, Balloon Systems
–
–
“On the whole, the responses were very positive”
One member commented:
–
My response to member (via Cathey) on 12/15/06
•
•
•
•
"It seems to me that the use of NDA to obtain a result is of interest to many
disciplines. However, should the method itself be represented in AIAA is a TC? The safety
folks use this to create flight rule for our balloons which is important. But is the probability
theory itself in need of representation? I think not."
Non-deterministic Approaches (NDA) are much more than probability theory. NDA encompass
the field we call "uncertainty quantification" and it includes techniques such as probability
theory, fuzzy sets, possibility theory, evidence theory, convex models, info-gap theory, etc.
Even if NDA meant only probability theory, application of probability theory to
structural/mechanical/thermal problems requires efficient and accurate algorithms and analysis
strategies. Thus, applied probability theory itself is still a very active area of research and
development, and will continue to be as we ask it to solve ever increasingly challenging
problems.
The proposed NDA TC is technology oriented as opposed to application oriented, which may be
fueling the confusion. Many of our members and conference attendees are engineers working
at aerospace companies who are faced with problems that can only be solved using NDA.
Others are methods developers. Solutions to current and challenging reliability problems go
way beyond what's available in standard probability textbooks, and that's precisely where NDA
are required. Our TC brings these two groups together, as well as supports many of the other
areas within AIAA (structures, materials, dynamics, etc.)
There could be a viewpoint issue/problem here as well. If you are only an occasional user of
basic probability theory, you may not be aware of the broad and rapidly growing field of NDA
driven by the needs of industry. I'm not sure if this is the case here, but I have run into before.
20
Support, cont’d
• Thomas Beutner (chair) & Peter Hartwich, (chairelect), Fluid Dynamics
– Non-deterministic are relevant to structures, to fluids, to
thermal sciences. Thus, there's inherent overlap with
established TCs
– If the goal of this TC is to sponsor a conference that will
collocate with structures, then is a new TC needed?
– AIAA's total membership is stable if not decaying. In this
general environment, is it advisable that AIAA keeps creating
new TCs?
– [Hartwich] In summary, my vote is against establishing an
NDATC.
– [Beutner] I suggest tabling the decision on a new TC for now
and utilizing the existing TC structure to advance NDA and
create a sustainable annual or biennial conference
21
Support, cont’d
• Mary Mahler, Structures
– With full consensus from the membership and friends of the AIAA
Structures Technical Committee, it is my pleasure to announce that
the Structures TC fully endorses the formation of the NonDeterministic Approaches Technical Committee for AIAA. I have
talked to the senior membership and there is total agreement that
the NDA Working Group had added a valuable aspect to the
aerospace industry. It is a technology that has come into its own
right and should be a technical committee for AIAA. With this area
of interest only growing in interest and research and practice in
production, the group that has several senior members and is
under the current leadership of Dr. Ben Thacker should be a
technical committee of AIAA.
The members of the Structures TC had no reservations of this
endorsement.
If there are any questions or further details to this endorsement,
please feel free to contact me. We look forward to working with
Ben and the soon-to-be NDA TC in the future.
22
Recommendation
Establish the NDA
Technical Committee
23