Submitted by Family

A seminal mind has departed: His students and the whole engineering community shall miss a concerned, rational engineer and scientist, whose actions were broadly based in the desire to improve the world in which we live. Though M.L Williams was associated with academic institutions throughout his career he demonstrated a firm belief in practical, hands-on engineering. He was a Registered Engineer and has had a major influence in guiding national programs of defense research, saving millions of dollars through judiciously supporting, criticizing or phasing studies and programs. His practical insights transitioned into engineering management through guidance of (over 20) start-up engineering ventures, which depended critically on mature engineering judgment and the teaching by his economics mentor Economics professor Horace Gilbert while a graduate student at Caltech.

Max Lea Williams, Jr. was born on 22 February 1922 in Aspinwall, Pa. He attended the Carnegie Institute of Technology—now Carnegie Mellon University— graduating in 1942, with a B.S. in mechanical engineering (aeronautics option). Being drafted upon graduation to active duty in the air force provided opportunities in maintenance as well as flight testing: He flew in the Northrop Flying Wing (today no longer of only historical interest) and the C-74 Douglas Globemaster, then the largest cargo plane. Upon release form the air force he enrolled at the Graduate Aeronautical Laboratories of the California Institute of Technology where he received his Ph.D. in 1948 and was subsequently appointed to the professorial ranks.

In this environment it was the swept wing program, necessitated by the arrival of high speed flight of both air craft and missiles, which led him to the singular stress fields in corners resulting from various sweep angles, with a 90 o sweep representing a crack. This development defined the universal nature of the stress field at the tip of a crack, which achievement, in the form of a series/eigenvalue expansion became the cornerstone for the field of fracture mechanics through the identification of the stress intensity factors KI (tension) and KII (shear) as the single most important parameters controlling fracture. This expansion, often called the Williams series, also allowed the direct interpretation of the stress intensity factor in terms of the local (elliptical) radius of curvature at the tip which should prove useful in numerical analyses: first in collocation analysis of fracture geometries and second in finite element analysis using singular crack tip elements. Fracture mechanics is today a mature field, which M.L. Williams uniquely helped to shape. Today, no structural fracture/failure analysis could be conceived without his contribution.

Characteristic of his broad engineering thinking were his almost immediate implications of these and related results for cohesive fracture to earthquake motion along seismic faults (1959, Bulletin of the Seismological Society of America), and to the field of adhesive fracture. His original observation of 1959, that cracks at interfaces between two linearly elastic solids engender a complex singular stress field involving a logarithmically oscillating character has ultimately dominated the intense studies of bonding and adhesion mechanics in the 1980s/1990s and fostered the desire to expand the use of linear elasticity into the application of locally nonlinear constitutive behaviors. Moreover, his interest in adhesive fracture precipitated, through his students and co- workers as well as “academic grandchildren”, the re-orientation of the community served by the Adhesion Society from its primarily chemistry-oriented viewpoints into accepting the major role which mechanics plays in the failure of adhesive bonds.

In his forward looking manner, while still at Caltech, he founded the International Journal of Fracture in 1963 as an Engineering Specialty Journal, and led the same with his wife, Dr. Mel Williams, until turning its reigns over to his student Prof. R.A Schapery in 1996 and to his academic grandson, Prof. K. Ravi-Chandar in 2000. Through this international venue as well as founder and Editor-in-Chief of the International Conference of Fracture he maintained a worldwide network with and for participants in this important engineering discipline.

With the ascent of the solid propellant missiles for strategic and tactical purposes during the height of the cold war M.L. Williams became a major contributor to and organizer of the structural integrity community, in which his knowledge of fracture was paramount, though modified into the viscoelastic materials range, materials that had been previously anything but a staple in the mechanical engineering arsenal. He became nationally instrumental in developing the tools for the fail-safe operation of solid propellant rocket motors (e.g. Polaris, SRAM, Minuteman) which achievement made the national defense and space efforts viable. His contribution to further the understanding of polymeric materials possessing time or rate dependent properties was unquestionably visionary and path breaking.

The influence of those developments concerning the mechanical behavior of polymeric propellant component were felt, e.g., through the Richard Feynman analysis of the Challenger disaster as well as throughout the whole engineering field where mechanical applications of polymers in today’s engineering environments are involved. These achievements led in a direct line through his students and “academic grandchildren” to founding the International Journal of Time-Dependent Materials, where he served from its inception as an Honorary Member of the Editorial Board. His international impact on the proper conduct of the analysis of viscoealstic structures thus parallels his influence on the fracture behavior of non-polymeric structures.

Moreover, his understanding of the needs and capabilities of the chemists in the solid propellant rocket and polymer industries – notably through his friends Profs. F.R. Eirich and F. N. Kelley – allowed him to influence a much wider range of technical problems than mechanics alone would have allowed. This influence, which reached NATO level, was further widened through his visionary consulting for virtually all companies involved in the production of solid-fuel rockets, and thus had a tremendous impact on the national defense complex as well as NASA’s space efforts.

With his gradual transition from being a “hands-on professor” to academic administration through his positions as dean in the engineering schools, first at the University of Utah (1965-73), and then at the University of Pittsburgh (1973-85), Prof. Williams widened his engineering perspective and range of operations further. Through his many industrial contacts at the administrative levels he was very effective in translating the fundamentals of the engineering discipline into both planning advances as well as engineering designs. His service to the engineering community and the general public is reflected in numerous positions of an advisory role, much of it for the US Government: While serving on the National Materials Advisory Board he chaired its Council on Materials, Structures, and Design; he also chaired the Structural Mechanics Sub-committee for Automotive Research of the Presidential Office of Science and Technology Policy and became a participant in the Defense Science Board. He devoted 10 years to the Advisory Committee for Engineering of the National Science Foundation (1969→) and served a four year term on the U.S. Air Force Scientific Advisory Board, all of which contributed to his receiving the Meritorious Civil Service Award from the US Air Force, (1989). He was a Member of the National Engineering Advisory Board of Mercer University.

His intense influence on the Structural Integrity Advances for solid propellant rocket motors, and his extended service in the form of his Chairmanship of the Mechanical Behavior Committee of the Joint Army-Navy-Air force Solid Propellant Information Agency (1958-1976) as well as the NASA Research and Technology Advanced Committee on Chemical Rocket Propulsion (1968-1973) was also recognized via the Solid Rocket Distinguished Technical Achievement Award by the American Institute of Aeronautics and Astronautics (1988). Concurrent with these Solid rocket related issues he became a Consultant to the Office of the Undersecretary of Defense for Research and Engineering (1970-91) and to the Department of State as a Consultant in the Bureau of Intelligence and Research (1973-1981).

His national impact is memorialized further though his numerous additional involvements and chairmanships for government agencies. These encompassed the National Institute of Dental Research (Biomaterial Research Advisory Committee), the National Science Foundation, the National Aeronautics and Space Agency, and the National Materials Advisory Board where he was Chairman of its Council on Materials, Structure and Design. For the Office of Science and Technology Policy he chaired the Structural Mechanics Committee for the Interagency Task Group on Cooperative Automotive Research, and was an Associate Member of the Defense Science Board. For approximately twenty years he served as a consultant in structure and materials for the Department of Defense. Professor Williams completed a four-year term as a member of the U.S. Air Force Scientific Advisory Board in 1990 and, upon “official retirement”, during 1985-87 held a two-year appointment to the General Lew Allen Research Chair at the U.S. Air Force Institute of Technology, Wright-Patterson Air Force Base in Dayton as Distinguished Visiting Professor of Aeronautics. In the subsequent year, 1987-88, he became Science Advisor to the Commander of the Acquisition Logistics Center at Wright-Patterson AFB before returning to the University of Pittsburgh.

His advisory functions within government circles had its industrial counterpart. He was very active in numerous industrial enterprises; an excerpt list comprises:

San Fernando Laboratories, CA, (1960-1964); Mathematical Sciences Corp. CA, (1962- 1966); Space Ordinance Systems, CA, 1963-1964); Mathematical Sciences Northwest, Inc. WA; (1965-1966); President, Utah Engineering Development Foundation (1969- 1979). Terra Tek, UT, (1973-1977); Vitrain Corp., NV. (1979-cont.); Automation Systems, Inc. CT, (1981-1984); Gulf Drilling Co, CA (1981-1988); Taylor and Turner Venture Capital Co., Member of Investment committee (1982→); Refractory Composites Inc., CA, Technical Advisory Committee (chair, 1985-1988); Technical Advisor to the Boston Capital Corporation.

Prof. Williams was publicly recognized much too late for these his outstanding achievements and services, for his many forms of national involvement and for his widely ranging support in the engineering community by his election to the US National Academy of Engineering in 2003. During the 1993-94 period, he was an Alexander von Humboldt Visiting Research Professor at the Fraunhofer Institut für Werkstoffmechanik in Freiburg, Germany. In 1995 he received the Distinguished Alumni Award from the California Institute of Technology. Since 1995 he was an Adjunct Professor of Aeronautics at the University of Texas, Austin.

His professional activity is further illustrated by his service and membership in numerous organizations including being a Founding Member, of the International Congress on Fracture (1965) and being a member of its Executive committee. He was elected a Fellow of the Society of Experimental Mechanics, the American Institute of Aeronautics and Astronautics, the American Association for the Advancement of Science, an Honorary Fellow of the International Congress of Fracture, besides being a member of Tau Beta Pi, Sigma Xi and Theta Tau. Besides the normal participation in the mechanically oriented engineering societies he was a ember of the Utah Academy of Sciences, Arts and Letters; the New York Academy of Sciences ; the American Chemical Society (Div. of Rubber Chemistry); the Society of Rheology and the American Society for Engineering Education.