Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 118
OCR for page 119
DO N ALD E . H U D S O N
1916–1999
Elected in 1973
“For the development of widely used instruments to
record destructive earthquake ground shaking.”
BY MIHAILO D. TRIFUNAC
SUBMITTED BY THE NAE HOME SECRETARY
DONALD ELLIS HUDSON, Don as he was known to his
friends, died of heart failure on April 24, 1999, at the age
of 83. By the time of his death he had built a distinguished
career of teaching, research, and service, spanning a broad
range of science and engineering and centered in earthquake
engineering. His work extended from experimental mechanical
engineering, geophysical engineering, vibration engineering,
rocketry, and underwater ordnance design during World
War II to the development of instrumentation and data
processing in earthquake engineering.
Don was born on February 25, 1916, in Alma, Michigan.
In 1924, to avoid hay fever, his family moved to Pasadena,
California, where he attended Franklin Elementary School,
Woodrow Wilson Junior High, and Pasadena City College
and then switched to the California Institute of Technology
(Caltech) in his junior year in 1936. He completed his B.S.
degree in 1938, M.S. degree in 1939, and Ph.D. in 1942. He
then began his distinguished 39-year-long career at Caltech.
He was assistant professor of mechanical engineering (1943–
1949), associate professor of mechanical engineering (1949–
1955), professor of mechanical engineering (1955–1963), and
professor of mechanical engineering and applied mechanics
(1963–1981). He retired from Caltech with emeritus status in
119
OCR for page 120
120 MEMORIAL TRIBUTES
1981. From 1981 to 1985, Don chaired the Department of Civil
Engineering at the University of Southern California School of
Engineering, where he held the Fred Champion Professorship
in Civil Engineering. He retired from USC in 1985.
Hudson’s first exposure to earthquake studies, which
would later guide him in his pioneering work in earthquake
engineering, dated back to his undergraduate and graduate
studies at Caltech where he and some of his classmates,
who eventually also became leaders in earthquake studies
(Walter Munk, Ben Howell, Egor Popov), took classes and
interacted with Guttenberg, Benioff, Richter, von Kármán,
and Biot. While Don was a graduate student, von Kármán
and Biot completed their book Mathematical Methods in
Engineering (New York: McGraw-Hill, 1940), which included
the basic theory of structural mechanics and dynamics. Thirty
years later, in the mid-1960s, when I took Don’s class in the
dynamics of structures, the simplicity and elegance of the
physical formulation of the von Kármán and Biot approach
were still evident. Don’s lectures were exceptionally well
prepared, and his blackboard work was like a Dürer painting,
photographically perfect to the minute detail.
Don’s thesis adviser and mentor was Frederick C. Lindvall,
who later chaired the Division of Engineering at Caltech (from
1945 to 1969). During the World War II projects at Caltech,
Hudson worked for the jet-assisted takeoff group, which was
headed by Lindvall. They developed methods for carrying
rockets on an airplane and launching them. When the U.S.
Navy needed to solve the stability problem of aircraft-launched
torpedoes, Lindvall and his group set up the testing facilities,
behind Morris Dam, above Azusa, and in China Lake, which
eventually became the China Lake Naval Ordnance Test
Station. The stability of the torpedoes was solved by adding
a shroud ring over the tail of a torpedo—just in time to build
several thousand torpedoes for the battle of Midway. During
these projects, Don worked with many future leaders in
engineering and applied sciences at Caltech (C. Anderson, C.
H. Wilts, and R. B. Leighton).
OCR for page 121
DO N ALD E . H U D S O N 121
In 1958–1959, Hudson spent six months in India, at the
University of Roorkee, sponsored by the Technical Cooperation
Mission of the U.S. State Department (subsequently the
Agency for International Development). Roorkee, the oldest
technical institute in Asia (formerly the Thomason College of
Engineering), was founded by the British to train surveyors for
the North India canal system. Today it is the Indian Institute
of Technology, Roorkee. During a visit to Caltech in 1957,
Professor A. N. Khosla, then vice chancellor and president of
the University of Roorkee, was impressed with the dynamic
measurement laboratory Hudson had set up at Caltech, and
arranged with Caltech President Lee A. DuBridge for Don to
take a leave of absence and go to Roorkee. Don’s assignment
was to organize a dynamics measurement laboratory there
and to teach courses in dynamic measurements and structural
mechanics. This stay in India marked the beginning of a long
and fruitful cooperation between Roorkee and Caltech faculty
and students and the beginning of earthquake engineering in
India. Several times Don went back to India to evaluate their
progress.
He was also a member of the steering committee and
Caltech representative on the Kanpur committee, which
coordinated establishment and organization of the American-
sponsored I.I.T. campus at Kanpur. One of the people who
came over to work with Don at Caltech was Jai Krishna. Later
Krishna became vice chancellor of Roorkee and president of
the International Association for Earthquake Engineering and
founded the Indian Academy of Engineering in Delhi. Don
Hudson was the first and for many years the only foreign
member and until his death the only earthquake engineer
from America to be elected a member of this highly selective
academy. In 1978 during the world conference on earthquake
engineering, Prime Minister Indira Gandhi held a tea party
at her house and on behalf of her father thanked Don for
his contributions and help with establishing the earthquake
engineering program in India. Don always felt that this was a
remarkable expression of appreciation and gratitude, and he
proudly shared his memory of the event with friends.
OCR for page 122
122 MEMORIAL TRIBUTES
Following the first steps at Caltech made by von Kármán
and Biot in the early 1930s, the dynamic response of structures
to earthquake shaking remained in the academic sphere
of research for many years and did not gain widespread
engineering acceptance until the early 1970s. There were two
main reasons for this. First, computation of the response to
earthquake ground motion, without digital computers, led
to formidable numerical difficulties; second, there were only
a few well-recorded accelerograms that could be used for
that purpose. This started to change in the 1960s with the
arrival of digital computers and the commercial availability
of strong-motion accelerographs. By the late 1960s and early
1970s, however, the digitization of analog accelerograph
records, organized by Hudson and his graduate students at
Caltech, and the digital computation of ground motion and
of the response spectra were developed completely. Then in
1971 with the occurrence of the earthquake in San Fernando,
California, which was recorded by 241 accelerographs, the
modern era of earthquake engineering was launched.
Don was among the first to recognize the significance of
the availability of a comprehensive and accurate database
for future developments of earthquake engineering. With
T. Caughey, his former student and later a faculty colleague at
Caltech, Don invested considerable effort to develop a special-
purpose analog computer (Mark II) for computation of the
response spectra from recorded strong-motion accelerograms,
but the process was time consuming and the results were not
accurate. In retrospect, it is clear and logical that in the mid-
1960s Hudson decided to gather all important records of strong
ground motion and to organize digitization, processing, and
dissemination of digital strong-motion data, a conditio sine qua
non for all subsequent developments in modern earthquake
engineering. Von Kármán and Biot formulated the response
spectrum method in earthquake engineering, but it was Don
Hudson who made modern analyses possible by gathering
and processing the data, thus providing a sound and realistic
experimental basis for the theory.
OCR for page 123
DO N ALD E . H U D S O N 123
Don was erudite; he read widely in history and literature;
and he loved music, Oriental art, and philosophy. He had
an impressive collection of classical music records and was
always willing to share his rare books on Buddhism and
Indian art. He loved chamber music and enjoyed travel and
archeology in Europe, India, Japan, and South America. His
travel was often combined with work for the United Nations,
foreign universities, and international conferences.
A bachelor in the earlier part of his life, Don married Phyllis
Henderson in 1972. They organized and supported many
chamber music performances at Caltech and enjoyed traveling
together.
Don’s many achievements did not go without recognition.
He was elected to the National Academy of Engineering in 1973
and to the Indian Academy of Engineering in 1987. He was
president of the Seismological Society of America (1971–1972)
and president of the International Association of Earthquake
Engineering (1980–1984). In 1989 the American Society of Civil
Engineers awarded him the Nathan M. Newmark Medal,
and in 1992 the Earthquake Engineering Research Institute
awarded him the Housner Medal.
Don was a patient, thoughtful, and generous gentleman.
The respect and immense influence he commanded were
the result of his reputation for fairness and his ability to lead
through reason and unselfish motives, which were aimed
for the benefit of others and for the common good. He had
the ability to attract and to lead his students and coworkers
with unassuming suggestions and by carefully listening to
their views and ideas. His students continue to emulate and
to propagate his methods and ideas on how to educate young
people and new creative minds. Theodore von Kármán, one
of Don’s teachers, was cited for saying that “scientists study
the world as it is, but engineers create the world that has
never been.” We will always remember Don as our teacher
who helped create those engineers. He was a friend and
communicator par excellence.
