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B.F.スペンサー教授へのインタビュー
B.F.スペンサー（ノートルダム大学）

インタビュア：
西谷章（早稲田大学）

スペンサー教授（ノートルダム大学）とのインタビューを掲載します。同教授は、2001 年の第 1 回地震工学研究
発表討論会のさいに招待講演を行うなど、日本の多くの研究者の方々との親交を持っています。この記事は、ス
ペンサー教授の来日機会を利用した面談、およびメール通信によるインタビューをもとに構成したものです。日本
語訳にすると微妙なニュアンスの違い等も生じますので、英語のままとします。
スペンサー教授には、非常に多忙の中、大変好意的にこの企画に協力して戴きました。多くの時間を費やして、学生時代のこと、研究分野のこと、中国語のことなどを話してもらうことができました。この場を借りて、スペンサー
教授に御礼申し上げます。
NISHITANI (N): Thank you for joining us, Dr. Spencer. You are
the very first person for JAEE Newsletter interview program.

your academic background. According to my understanding,

Perhaps you are one of the most well-known foreign

Mechanics (TAM) at University of Illinois at Urbana-Champaign

researchers

engineering(UIUC). There are only few similar departments in Japanese

research community. Speaking of our personal relationship, I

universities, I suppose. Could you speak to us about the field offirst met you in Hawaii in 1993, when the first international

theoretical and applied mechanics, in particular focusing on theworkshop on structural control was held. Since then, we haverelationship with earthquake or civil engineering?

had many opportunities to get together. Nearly ten years since

SPENCER:Engineering mechanics is the basic study of fluids and solids

amongJapanese

earthquakethat time. Time passes so quickly.

you obtained the Ph.D. degree in Theoretical and Appliedand how they react to applied forces. With roots in physics andLet's get started. To begin with, I would like to ask you aboutmathematics, engineering mechanics provides the basis for all

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the University of Illinois?

and engineering, mechanical engineering, and aerospaceengineering. As such, having my M.S. and Ph.D. degrees in

SPENCER:My research as a graduate student focused on computational

Theoretical and Applied Mechanics provided me with a very

stochastic mechanics, and in particular on determining theversatile background.

reliability of a randomly excited hysteretic oscillator. The
solution of a large class of physically motivated problems

N: I know you were a very good student while you were in
graduate school at the University of Illinois. When I visited Prof.

arising in stochastic dynamics is facilitated by appropriate

Bergman at the Urbana-Champaign campus, I found your nameMarkovian. The reliability of an oscillator with hysteretic

in certain plaque listing the names of certain students. Why was

restoring force can be viewed as a first passage problem inyour name on this plaque?

random vibration, which can be posed as the solution of the

SPENCER:I was an instructor teaching courses such as statics, dynamics,

backward Kolmogorov equation, the formal adjoint of theand mechanics of solids to undergraduate students for five ofKolmogorov equation is an elliptic-parabolic initial-boundary

my eight semesters as a graduate student at the University ofvalue for which general solution is unavailable. My doctoral

Illinois. The enrollment in these classes ranged from 47 to overresearch addressed the computational solution of this partial

100 students. In recognition of my classroom performance, thedifferential equation using an upwinded finite element method

Department made me the 1985 recipient of the J.O. Smithand was published by Springer-Verlag in a monograph entitledAward as the Outstanding Young Teacher in Engineering

Reliability of Randomly Excited Hysteretic Structures.

modeling of the system such that its response process is

Fokker-Planck equation. For this problem, the backward

Mechanics and placed my name on this plaque.

N: What kind of research did you do in your doctoral thesis at

N: Your thesis supervisor was Prof. Larry Bergman, who is oneof my very good friends as well. What was he like as the地震工学ニューズレター Vol.2 No.１

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supervisor? Do you think that you are the same kind of

Larry at UIUC and have tried to emulate this style as asupervisor as he was? One thing that seems to Japanese very

supervisor in my subsequent career as a faculty member atunusual regarding the relationship between doctoral students

Notre Dame.

and thesis supervisors is that most of former Ph.D. students calltheir former supervisors by their first names, after getting thedegree. Did you feel some hesitation when you first call Prof.

N: After receiving your doctoral degree, you joined the facultyof civil engineering at the University of Notre Dame. What madeBergman "Larry"?

you go to the field of civil engineering? You could have chosen

SPENCER:
Although not the case at all universities in the US, in oura field other than civil engineering.

department at UIUC, all of the graduate students called the

SPENCER:As you know, my undergraduate degree is in mechanicalfaculty by their first names. However, hearing other students

engineering. I also worked for the General Motors Corporation

call Larry by his first name was very strange. It took a few

in Detroit for several summers learning about vehicle vibration

months to become accustomed to this practice.

problems. My graduate studies also focused on vibration
problems, with an emphasis on randomly excited systems.

Regarding Larry's style as a supervisor, I believe that I speak

Many disciplines conduct research on such topics. Indeed,

for all of his former graduate students in saying that he is a truly

uponexcellent mentor. Although he never stated it, as opposed to theopportunities were available in aerospace, mechanical, and civil

research itself being the "product" of his labors, I believe thatengineering. However, the most advanced research in the area

Larry views the "product" as being his students. Of course, toof probabilistic mechanics was being conducted in civil

effectively educate students, one must teach them how toengineering. At the same time, the research and educational

conduct high quality research, but in my experience, the focus

opportunities offered at the Department of Civil Engineering at

is on the student. I benefited tremendously from working with

the University of Notre Dame seemed too attractive to pass up.

graduation

from

the

TAM

department

at UIUC,

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I think that I made the right decision to join the ranks of the civilengineers!

Fatigue and Fracture Reliability
B.F. Spencer, Jr. and J. Tang, "A Markov Process Model for

N: Speaking of your research career, as you mentioned
minutes ago, your initial research was in computational

Fatigue Crack Growth," Journal of Engineering Mechanics,
ASCE, Vol. 114, No. 12, pp.2134-2157, 1988.

stochastic mechanics. Subsequently you conducted researchwith regard to problems in fatigue and fracture reliability, active

Active Structural Control

control of structures, and now magnetorheological (MR)

B.F. Spencer, Jr., M.K. Sain, C.-H. Won, D.C. Kaspari Jr. anddamper-related semiactive control. What would you pick up as

P.M. Sain, "Reliability-Based Measures Of Structural Control

your best five or ten papers, if possible?

Robustness," Structural Safety, Vol. 15, pp. 111- 129, 1994.

SPENCER:I am not sure if the following papers are the "best", but they are

S.J. Dyke, B.F. Spencer, Jr., P. Quast and M.K. Sain, "The Role

the ones that I like the best.

of Control-Structure Interaction in Protective System Design,"
Journal of Engineering Mechanics, ASCE, Vol. 121, No. 2, pp.

Computational Stochastic Mechanics

322-338, 1995.

B.F. Spencer, Jr., Reliability of Randomly Excited Hysteretic
Structures, Lecture Notes in Engineering (series editors: C.A.

S.J. Dyke, B.F. Spencer, Jr., P. Quast, D.C. Kaspari, Jr., andBrebbia and S.A. Orszag), Vol. 21, Springer-Verlag, 1986.

M.K. Sain, "Implementation of an Active Mass Driver Using
Acceleration Feedback Control," Microcomputers in Civil

B.F. Spencer, Jr. and L.A. Bergman, "On the Numerical Solution

Engineering: Special Issue on Active and Hybrid Structuralof the Fokker-Planck Equation for Nonlinear Stochastic

Control, Vol. 11, pp. 305-323, 1996.

Systems," Nonlinear Dynamics, Vol. 4, pp. 357-372, 1993.

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Smart Damping (Semiactive Structural Control) using MR
Fluid Technology

N: And what is your recent research interest?

S.J. Dyke, B.F. Spencer, Jr., M.K. Sain and J.D. Carlson,"Modeling and Control of Magnetorheological Dampers for

SPENCER:My research interests continue in the use of MR dampers for

Seismic Response Reduction," Smart Materials and Structures,protection of civil infrastructure systems. A tremendous amountVol. 5, pp. 565-575, 1996.

of progress has been made since we started working with the
Lord Corporation on this research topic in 1994. Last year saw

B.F. Spencer, Jr. S.J. Dyke, M.K. Sain and J.D. Carlson,

the first full-scale implementation of MR dampers for civil"Phenomenological Model for Magnetorheological Dampers,"

engineering applications achieved. Nihon-Kagaku-Miraikan, theJournal of Engineering Mechanics, ASCE, Vol. 123, No. 3, pp.

Tokyo National Museum of Emerging Science and Innovation,

230-238, 1997.

has two 30-ton, MR Fluid dampers installed between the 3rd
and 5th floors. The dampers were built by Sanwa Tekki using

B.F. Spencer, Jr., S.J. Dyke, and H.S. Deoskar, "Benchmark

the Lord Corporation MR fluid. Currently being retrofitted with

Problems in Structural Control - Part I: Active Mass Driver

stay-cable dampers, the Dongting Lake Bridge in Hunan, China

System;Earthquake

will constitute the first full-scale implementation of MR dampers

Engineering and Structural Dynamics, Vol. 27, pp. 1127-1147,

for bridge structures. Two Lord SD-1005 (www.rheonetic.com)

1998.

MR dampers are being installed on each cable to mitigate cable

Part

II:

ActiveTendonSystem,"vibration. Seeing this research come to fruition has been
G. Yang, B.F. Spencer, Jr., J.C. Carlson and M.K. Sain,

extremely gratifying.

"Large-Scale MR Fluid Dampers: Modeling and Dynamic
Performance Considerations," Engineering Structures, Vol. 24,

Most recently, my students and I have expanded our research

pp. 309-323, 2002.

to include structural health monitoring. Although structural地震工学ニューズレター Vol.2 No.１

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civil

might imagine. My entire career, almost 17 years, has been

engineering structures is still a relatively young field, it holds

spent at Notre Dame, and I've enjoyed nearly every moment.

great promise. Similarly, structural response control has

Founded in 1842, Notre Dame is a Catholic University offering

revolutionized the way that buildings and bridges can respondundergraduate, graduate and professional programs to 11,000

to dynamics loads. Combining these two technologies together

students. Notre Dame's research programs cover a broadoffers even more opportunities. We seek to develop an

spectrum of disciplines and build upon her long-establishedintegrated system, including appropriate hardware, software,

reputation for excellence in undergraduate education. The

and networking components for acquisition and transmission of

aerodynamics of glider flight and the transmission of wirelessthe data, as well as development of new diagnostic methods.

messages were pioneered at the University, and the formulae
for synthetic rubber were discovered at Notre Dame. The

N: I heard that you are going to move to the civil engineering
department at the University of Illinois at Urbana-Champaign incampus is truly beautiful, with two lakes on campus and thethe coming August. How many years have you spent at

faculty numbered 736 full-time and 355 part-time. Founded in

University of Notre Dame? Please tell us about what the1873, the College of Engineering has 105 teaching andUniversity of Notre Dame is like. For instance, how many

research faculty members in five departments: Aerospace andstudents are there? How many faculty members? How many

Mechanicaldepartments in the College of Engineering? How much are theEngineering and Geological Sciences, Computer Science andtuition and fees? The University of Notre Dame is in South

Engineering,

Bend, Indiana. What is South Bend like?

approximately 1000 undergraduate and graduate students in

SPENCER:
Effective fall of 2002, I will join the faculty at the University of

the College. The undergraduate tuition, room and board for one

Illinois. The decision to leave Notre Dame was difficult, as you

famous "Golden Dome". In 2000-01 Notre Dame's regularEngineering,andChemicalElectricalEngineering,Engineering.

academic year is approximately $31,000.

There

Civil
are

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South Bend, with a metropolitan area of nearly 250,000,

that

combines the lifestyle of a smaller community with the cultural"Department of Civil Engineering?" How many faculty members

and economic attractions found in much larger cities. Housing

are there in the civil engineering department at University of

costs and the overall cost of living are quite low. South Bend's

Illinois? Are there many professors doing researches about

economic base is a stable mix of large and small industries withstructural dynamics or control over there?

a highly developed retail, health care, and service economy.

SPENCER:
Some universities, such as Washington University in St. Louis,

There are two "Fortune 500" companies in the area.

have

still

7/9

maintained

theconventional

name

of

still keep the name "Department of Civil Engineering." At the

N: You should have a lot of memories regarding your life in
University of Notre Dame. Could you say something about your

University of Illinois at Urbana-Champaign, the offical name ofmost memorable experiences at the University of Notre Dame?

Engineering. The Department was founded in 1871 and has

SPENCER:My best memories of Notre Dame derive from working closely

53 full time faculty members in the areas of environmental,

with so many excellent colleagues and students at the campus.

geotechnical engineering. The faculty's activity in structural

the department is the Department of Civil and Environmental

structural,

construction,transportation,

hydraulic,anddynamics and control iscurrently limited, but I am pleased to

N: May I go to the next subject, which is in regard to University
of Illinois at Urbana-Champaign? What is the official name of

say that Prof. Nicholas P. Jones has accepted the position as

the civil engineering department? In these days, many of civil

expertise in wind engineering will be a welcome addition to theengineering departments in the US appear to change theDepartment.

Department Head, effective this fall. His background andnames such as the Department of Civil and GeotechnicalEngineering, the Department of Civil and Environmental
Engineering, and so on. Are there a few departments in the U.S.

N: You will become the Newmark Professor of Civil Engineering
there. What is the official title of this position? Most of地震工学ニューズレター Vol.2 No.１

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earthquake engineering related researchers know the name of

Provost makes the final decision regarding who will be awarded"Newmark." How do you feel about being named to thisthe endowed professorships/chairs. In addition to the title, mostposition?

of these positions also provide a small research fund.

SPENCER:The name of my position is the Nathan M. Newmark Professorof Civil Engineering. I am deeply honored to have been

N: Recently I happened to know that you speak Chinese quite
fluently. I know you have had a very nice relationship withawarded this position, which carries the name of such an

Chinese structural control community. So, it would beoutstanding researcher and engineer.

convenient for you to speak Chinese language. That is quite
understandable. But when I heard you speaking Chinese, to be

N: We Japanese do not have such kind of professor system
and are not familiar with it. So, we are wondering who and how

frank, I was very much surprised. Your Chinese sounds like too

to decide or choose, etc. Could you give us some information

language at all. One of my Chinese friends said to me that yourabout the system like this?

pronunciation of Chinese was extremely good. How did you

SPENCER:
Some of the endowed professorships/chairs can be awarded tolearn to speak Chinese so fluently in such a short time?

good, even though I do not speak or understand any Chinese

anyone in the university; however, the Newmark Professorship

SPENCER:
While on an airplane returning from Japan in 1998, I struck up ais only for a faculty member in the Department of Civil andconversation with a man sitting next to me about theEnvironmental Engineering. Generally speaking, a donor will

importance of children learning a second language, andgive a certain amount of money to the University to establish ancommented that the choice of which language was not obvious

endowed professorship/chair. A committee is formed tofor a native English speaker. He suggested that Mandarine

evaluate potential candidates for these position and make

Chinese was the obvious language, since it is spoken by 20%

recommendations to the University administration. At UIUC, theof the world's population. He also noted that if one can read

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Chinese characters, then communication is also facilitated withsame or similar field? Or what kind of occupation would you like

Japanese and Korean people. While I did nothing at that time,

to choose other than university professor?

the comments of this man stuck with me.

SPENCER:
Actually, I feel that being a university professor is one of theAfter a workshop I organized in Guangzhou, China in 1999,

best jobs that one can have. You have the opportunity to work

Larry Bergman and I took a short vacation to the ancientwith bright young students and help them mature into

Chinese city of Xi'an. It happened that on the last day of the

independent engineers. You have the freedom to conduct

workshop, the USA had accidentally bombed the Chinese

research on whatever topic you wish. Your job is basically yourEmbassy in Belgrade, Yugoslavia.

During this time, thehobby. One has the chance to travel and meet wonderfulsituation was rather tense, but because I had purchased apeople such as yourself. I really don't think that I would choose

Chinese phrase book for this trip, we were able to get byanother path, even if given the opportunity.

without any big problems. This experience gave me theimpetus to start studying Chinese. After deciding to learn thelanguage, I was fortunate to be able to retain the wife of one

N: Thank you for taking your time. I appreciate very much. I
believe you will get much more successful at your newof the postdocs in our department as a tutor. This, of course,

university.

pressured me to keep up with my lessons. I have found theentire experience to be not only rewarding and useful, but also
a good way to relax in the evening. I hope that in the future I
will have the time and opportunity to learn Japanese as well.

N: If you did not study Engineering, what kind of field would you
choose to study? Or if you were reborn, would you choose the