Table Of ContentFOREWORD
This volume addresses the basic mechanisms of long term deterioration of engineering materials
and the development of short term laboratory or in-situ tests which will allow prediction of the extent
of this long term deterioration. All machines, structures and facilities deteriorate over a period of
years or decades and eventually wear out, break down, or become unproductive or unsafe.
Replacement costs to counter the deterioration are enormous. For instance, the US Federal Highway
Administration (FHWA) estimates that in the US there is an annual accruing "bridge deficiency" of $
2.3 billion (in 1980 dollars) and that the total expenditure for bridge repair and replacement from
1981 through 2000 was $ 102.6 biUion. Similar costs can be documented in many other sectors, from
transportation and manufacturing to electronics and MEMS. Understanding how to design
components and structures for optimal life performance is therefore very important and becomes
essential when new materials or new application areas are considered. Of high importance is also the
understanding of how to determine the optimal time to replace existing components or structures and
development of techniques to prolong their usefixl life. Once this understanding has been reached and
it has become possible to closely determine the life cycle of the most critical components of a
structure or system, then it becomes feasible to develop design methodology and/or inspection,
monitoring, and replacement strategies which allow significant extension of the life of the complete
system. This will result in significant savings to society. In order to reach this desirable goal it is
necessary to closely understand deterioration mechanisms at different scales and to have available
short term tests that can be used to reliably predict long term deterioration, durability and
performance, as discussed in this volume.
Objectives of the workshop
This book contains the proceedings of a workshop held at Berkeley, CA in October 2000. It brought
together engineers and scientists, who have received research grants from the National Science
Foundation under the 1998 initiative "Long Term Durability of Materials and Structures: Modeling
and Accelerated Techniques" (NSF 98-42). The purpose was to share results from the study of long-
term durability of materials and structures. The major objective was to develop new methods for
accelerated short-term laboratory or in-situ tests, which allov/ accurate, reliable prediction of long-
term performance of materials, machines and structures. To achieve this goal it was important to
understand the fundamental nature of the deterioration and damage processes in materials and to
develop innovative ways to model the behavior of these processes as they affect the life and long-
term performance of components, machines and structures. The researchers discussed their approach
to include size effects in scaling up from laboratory specimens to actual structures. Accelerated
testing and durability modeling techniques developed were validated by comparing their results with
performance under actual operating conditions. The main mechanisms of the deterioration discussed
included environmental effects and/or exposure to loads, speeds and other operating conditions that
are not fully anticipated in the original design. A broad range of deterioration damage, such as
fatigue, overload, ultraviolet damage, corrosion, and wear was presented. A broad range of materials
of interest was also discussed, including the full spectrum of construction materials, metals, ceramics,
polymers, composites, and coatings. Emphasis was placed on scale-dependence and history of
fabrication on resulting mechanical behavior of materials from the macrosc^e to the microscale.
In summary, the objective of this workshop was to establish a holistic discussion of deterioration
mechanisms relevant to structural and construction materials. Topics included the physics and
chemistry of the deterioration mechanism, develop new equipment to determine the degree of distress
caused by the deterioration and test the new methodology in field conditions. We hope that the results
of the workshop can lead to improved durability, life cycle performance, safety, reduced maintenance
and lower cost which in turn should lead to superior machines and structures.
Paulo J.M. Monteiro
Ken P. Chong
Jom Larsen-Basse
Kyriakos Komvopoulos
Editors
WORKSHOP ATTENDEES
Javier Balma KenP.Chong,PhD,PE
Civil & Environmental Engineering Director, Mechanics & Materials Program
University of Kansas CMS/Engineering Directorate
2008 Learned Hall National Science Foundation
Lawrence KS 66045 4201 Wilson Blvd, Suite 545
785-864-3826 Arlington VA 22230
ibalmafgiukans.edu 703-292-7008
kchongfglnsf.gov
Zdenek P. Bazant, PhD, SE
Walter P. Murphy Professor of Civil Richard M. Christensen, PhD
Engineering & Materials Science Research Professor
Northwestern University Aeronautics & Astronautics
EvanstonIL 60208-3109 Stanford University
847-491-4025/848-491-3351 Durand Bldg, Rm. 387A
z-bazant(a)jiorthwestem.edu Stanford CA 94305-40035
christensen(g>stanford.edu
Raimondo Betti, PhD
Civil Engineering & Mechanics Julio F. Davalos, PhD
Columbia University C.W. Benedum Distinguished Teaching
610MuddBldg Professor, Civil & Environmental
New York NY 10027 Engineering
212-854-6388 College Engineering & Mineral Resources
betti(g>civil.columbia.edu ESB, Rm 611, Evansdale Drive
West Virginia University
Zednek Bittnar Morgantown WV 26506-6103
Chair, Dept of Structural Mechanics 304-292-3031, X.2632
Czech Technical University davalos(glcemr. wvu.edu
Prague 6, Czeck Republic
++420-2-2435-3869 Grace Hsuan, PhD
bittnar(a)isv.cvut.cz 475 Kedron Avenue
Folsom PA 19033
Scott Case, PhD 215-895-2785
Materials Response Group [email protected]
Engineering Science & Mechanics
121-CPatton Hall, MC 0219 Y.C. Jerry Jean, PhD
Virginia Tech University Chemistry and Physics
BlackburgVA 24061 Chair, Dept of Chemistry
540-231 -3140 University of Missouri-Kansas City
scase(a),vt.edu 5009 RockNill Road
Kansas City MO 64110
816-235-2295
[email protected]
Christopher H.M. Jenkms, PhD, PE Dr. Victor C. Li, FASCE, FASME
Director, Compliant Structures Laboratory Professor & Director, ACE-MRL
Mechanical Engineering Civil & Environmental Engineering
501 E. Saint Joseph Street University of Michigan
Rapid City SD 57701 2326 G.G.Brown Bldg
605-394-2406 Ann Arbor Ml 48109-2125
[email protected] 734-764-3368
vcli(a),engin.um ich.edu
William Jordan, PhD, PE
Chair, Mechanical Engineering Program Richard A. Livingston, PhD
Louisiana Tech University Senior Physical Scientist
Ruston LA 71272 Office of Infi-astructure R&D, HRDI
318-257-4304 Federal Highway Administration
iordanrg>coes.latech.edu 6300 Georgetown Pike
McLean VA 22101
Jacob Jome, PhD 202-493-3063
Chemical Engineering dick.livingston(a)igate.fhwa.dot.gov
University of Rochester
Rochester NY 14627 Hongbing Lu, PhD
716-275-4584 School of Mechanical & Aerospace
iome(g).che.Rochester.edu Engineering
218 Engineering North
Akira Kuraishi Okalahoma State University
Graduate Student Stillwater OK 74078
Aeronautics & Astronautics hongbin(a)jnaster.ceat.okstste.edu
Stanford University
Durand Bldg Rm. 006D Wes Limi, Chief, Office of Infrastructure
Stanford CA 94305-4035 Research, MS-42
650-723-3524 California Department of Transportation
akirakfg.leland.stanford.edu New Technology And Research Program
1101 R Street
Kyriakos Komvopoulos, PhD Sacramento CA 95814
Mechanical Engineering 916-324-2713
5143 Etcheverry Hall [email protected]
University of California, Berkeley
Berkeley CA 94720-1740 Sankaran Mahadevan, PhD
510-642-2563 Director of Graduate Studies
kvriakos(a),me.berkelev.edu Dept of Civil & Environmental
Engineering
Box 6077, Station B
Jom Larsen-Basse, PhD Vanderbilt University
Director, Surface Engineering & Material Nashville TN 37235
Design Program 615-322-3040
Civil & Mechanical Systems Division sankaran.mahadevan(a)vanderbilt.edu
National Science Foundation
4201 Wilson Blvd,Rm 545
Arlmgton VA 22230 Gerald H. Meier, PhD
703-292-7016 Materials Science & Engineering
[email protected] 848 Benedum Hall
University of Pittsburgh
Pittsburgh PA 15261
412-624-9720
[email protected]
Yasushi Miyano, PhD Tom Sandreczki
Materials System Research Laboratory Dept of Chemistry
Kanazawa Institute of Technology University of Missouri-KC
3-1 Yatsukaho, Matto, 5009 Rockhill Road
Ishikawa 924-0838, Japan Kansas City MO 64110
mivano(alneptiine.kanazawa-it.ac.ip [email protected]
Paulo J. Monteiro, PhD Jian-Ku Shang, PhD
Civil & Environmental Engineering Materials Science & Engineering
725 Davis Hall University of Illinois at Urbana-Champaign
University of California, Berkeley 1304 West Green Street
510-643-8251 Urban IL 6180
[email protected] 217-333-9268
j [email protected]
Doug Parks
Division of Materials Engineering & C.T. Sun
Testing Services School of Aeronautics & Astronautics
5900FolsomBlvd Purdue University
Sacramento CA 95819-4612 West Lafayette IN 47907-1282
916-227-7007 765-494-5130
doug [email protected]. gov [email protected]
Ramana M. Pidaparti Michael Tolin
Mechanical Engineering (Caltrans) Division of Materials &
Purdue School of Engineering & Testing Services
Technology, lUPUI 5900 Folsom Blvd
723 W. Michigan Street Sacramento CA 95819
IndianapoUs IN 46202-5132 916-227-5297
317-274-6796 michael tolin(a),dot.ca.gov
ramana(a),engr.iupci.edu
Stephen W. Tsai, Professor/Research
Arron Rambach Durand Building, Rm 381
California DOT (Caltrans) Dept of Aeronautics & Astronautics
5900 Folsom Blvd Stsmford University
Sacramento CA 95819 Stanford CA 94305-4035
916-227-7236 650-725-3305
arronJam [email protected] [email protected]
Robert A. Reis Clifton Vining
Division of Materials Engineering & Dept of Mechanical Engineering
Testing Services Louisiana Tech University
5900 Folsom Blvd Ruston LA 71272
Sacramento CA 95819
916-227-7287 Aleksandra Vinogradov, PhD
[email protected] Mechanical & Industrial Engineering
Montana State University
Alberto A. Sagues, PhD, PE 220 Roberts Hall
Distinguished University Professor BozemanMT 59717
Civil & Environmental Engineering 406-994-6284
University of South Florida ENB-118 [email protected]
4202 E. Fowler Avenue
Tampa FL 33620-5350
813-974-5819
[email protected]
Paul Viraiani Max Yen, PhD
Federal Highway Administration Director, Materials Technology Center
6300 Georgetown Pike Southern Illinois University
McLean VA 22101 Carbondale IL 62901-6603
202-493-3052 618-536-7525
paul.vinnani(glfliwa.dot.gov jsulivan(g)^iu.edu
Yunping Xi, PhD
Civil, Environmental & Architectural Engineering
Campus Box 428
University of Colorado
Boulder CO 80309
303-492-8991
xiy{albechtel.colorado.edu
xi
WORKSHOP ATTENDEES
Long Term Durability of Structural Materials
PJ.M. Monteiro, K.P. Chong, J. Larsen-Basse, K. Komvopoulos (Eds)
© 2001 Elsevier Science Ltd. All rights reserved
INITIATIVE ON LONG TERM DURABILITY OF MATERIALS AND
STRUCTURES
J. Larsen-Basse and K.P. Chong
National Science Foundation
Arlington, VA 22230, USA
ABSTRACT
Fundamental research in durability of materials and structures have shown great potential for enhancing
the functionality, serviceability and increased life span of our civil and mechanical infrastructure systems
and as a result, could contribute significantly to the hnprovement of every nation's productivity,
environment and quality of Hfe. This initiative is aimed at developing innovative short-term laboratory or
in-situ tests, which allow accurate, reliable prediction of long-term performance of materials, machines
and structures. It is especially needed for new materials since such data are non-existing. The intelligent
renewal of aging and deteriorating civil and mechanical infrastructure systems includes efficient and
innovative use of high performance composite materials for structural and material systems. In this paper
the NSF initiative on durability modeling and accelerated tests, as well as research needs are presented.
KEYWORDS
Durability, accelerated tests, modeling, designer materials, life-cycle performance.
INTRODUCTION
Demands for better-performing, longer-lasting, safer, more economical, and more environmentally
fiiendly structures and machines are constantly pushing the envelope of technological capabilities and
engineering practice. As a result there are relentless moves towards close tolerances and use of realistic
life-cycle design, condition-based maintenance, and performance-based design. Li this environment, the
engineering designer is faced with the problem of finding usefiil and relevant materials property data for
use in the design of machines and structures which are expected to provide top performance for an
extended period of time. He or she will typically have access to "hard" data, i.e., repeatable and
reproducible results from short term laboratory tests, such as simple hardness, fatigue, imiaxial yield and
firacture tests; and even results from somewhat more complex standard tests, such as fracture toughness
or short-term salt spray or ultraviolet chamber exposure tests. The designer usually also has some much
more "soft", qualitative information on how a material has performed in the past under a given
combination of time, temperature, mechanical load, environment, etc. in the same or similar applications.
The skilled designer will usually be able to draw from his or her experience of connections between these
sets of "hard" and "soft" information for one particular material to make educated estimates of how a
different material, which gives somewhat similar results in short term tests, will perform under not-too-
different sets of long-term complex mechanical and environmental loading conditions.
This approach has served reasonably well in the past but has several shortcomings relative to the new
demands on tight design for performance. For example:
- it depends heavily on the experience and background of the designer,
- it does not deal well with synergistic interactions of several different types of loading, for example
cyclic stress and long-term corrosion. For creep of metals and viscoelastic materials, use of the
Larson-Miller parameter and similar approaches serve as semi-empirical ways to add the effects of
temperature and time, but similar parameters are lacking for most other situations,
- it does not readily allow for comparison of different classes of materials, for which the short-term
test results vary substantially, for example steel and polymer-matrix composites. This inhibits or
delays the adoption of new materials for many critical applications, and
- it does not provide adequate information to allow direct design-for-performance in specific, long-
term applications. For example, wear testing by the popular pin-on-disk apparatus may be a simple
way to discriminate between different materials for, say, hip implant use, but it is only marginally
relevant to a material's performance in the actual service and it does not permit any useful life-cycle
design.
With this general background in mind a number of NSF program directors held informal discussions
over a period of time. Some of the questions considered were the following:
- Have recent advances in the fields of modeling, computation, understanding of basic materials
properties, sensing, control, probability analysis, etc., reached the stage where we really can do
better than outlined by the problem set above, where we can begin to predict long-term performance
from short-term tests by quantitative approaches? And where we can confidently operate with
lower safety margins or safety factors and closer prediction of life to failure or time until
maintenance is necessary?
- Do we understand the different processes well enough to be able to closely predict their long-term
synergistic interactions, such as the combined effects of stress, corrosion and temperature
variations?
- Is there some basic generic approach, which has general applicability in diverse cases, maybe,
including model-based simulation and uncertainty and probability considerations?
- Do we have some quantitative or semi-quantitative ways of dealing with new materials, new
combinations of external loadings and environmental effects, or changes in these factors during the
life of a machine or structure?
- Are there any new short-term tests or NDE techniques that need to be developed to provide some of
the necessary information in a useful manner? And
- What new research should we try to stimulate in order to expedite development in this field?
- What are the long-term field data available and how do them compare with the
research results of proposed methods?
Durability of new materials involves the synthesis, laboratory and field testing, accelerated tests and
modeling, etc. Fig. 1 illustrates the size effects and mechanics (Boresi and Chong, 2000) involved.
Materials Structures/machines Infrastructure
Submicro4evel meso4evel macro4evel systems integration
Molecular scale Microns Meters Up to km scale
~micro-mecliaiiics ~meso-inecliaiiics ^beams '"bridge systems
^nanotechnology ~interfacial ^columns ^airplanes
designer materials smart structures high performance systems
Fig. 1. Scales in Materials and Structures
The discussions initially resulted in the support of a workshop focused on problems in the infrastructure
materials area, funded by NSF and organized by the Board on Infrastructure and the Constructed
Environment under the National Advisory Board of the National Research Council of the Academy
(NRC 1999). From the report of this workshop and additional discussions an NSF research investment
initiative was subsequently developed. It led to the research discussed at this meeting.
THE NRC WORKSHOP
The workshop was held at the National Academy of Sciences on August 24 and 25 of 1998. It defined
its role as ". a reconnaissance-level assessment of models and methods that are being used, or potentially
could be used, to determine the long-term performance of infrastructure materials and components."
(NRC 1999) The objectives were (NRC 1999):
- "define the objectives for infrastructure-based research that would use accelerated testing and
computational simulations to determine life-cycle performance
- assess the state of the knowledge base to identify gaps and overlaps in research activities
- establish outcome-oriented metrics for setting research priorities
- identify promising lines of research and collaborations"
The participants agreed that a "root cause" of the deterioration and failure of any system is related to
materials but that accelerated-testing methods, while they may potentially be used to rank the
performance of materials in real-world systems, they are not at present sufficiently reliable to make
system-life predictions.
The workshop proposed that development of useful life-prediction models for infrastructure systems
would require some of the following advances (NRC 1999):
a better fundamental understanding of infrastructure materials and systems, including interfaces and
degradation modes and spanning all size scales
a better understanding of the relevant characteristics of the operating environment
development of standardized test methods and databases
development of sensors for monitoring systems during construction and use
incorporation of economic models in life-cycle cost analyses.
The workshop also suggested that major obstacles to adaptation of life-cycle prediction models and
accelerated test procedures for infrastructure applications are two interrelated factors:
- poor integration of the relevant engineering community into materials-based infrastructure research,
and
- concerns about risk and liability
- It expressed the opinion that "practicing engineers have little opportunity to develop the same level
of trust in simulation models and accelerated laboratory tests as they have in their many years of
empirical field observations."
The workshop concluded that..."life-prediction models and accelerated-testing procedures have the
potential to increase the deployment of new materials in infrastructure applications and to improve
traditional materials..."
