c ilZtil BBSS I.U.--DEPT. OF THEORETICAL AND APPLIED MECHANICS CIRCULAR OF INFOR MAT I ON The Department of Arthur Newell Talbot Laboratory University of Illinois Urbana, Illinois THEORETICAL and APPLIED MECHANICS 19 5 3 The staff of the Department of Theoretical and Applied Mechanics welcomes you to Arthur Newell Talbot Laboratory. You are invited to inspect our facilities, discuss our work, and confer with those with whom you may have common interests. A staff member will gladly serve as a guide if you so desire. Please telephone or go to: DEPARTMENT OF THEORETICAL AND APPLIED MECHANICS ROOM 214, ARTHUR NEWELL TALBOT LABORATORY UNIVERSITY EXTENSION 3122 c The Full-Time Staff Thomas J. Dolan, Professor and Head of the Department Blaine W. Andersen, Instructor Frederick G. Bauling, Research Associate Winston E. Black, Associate Professor Arthur P. Boresi, Instructor Cletus E. Bowman, Assistant Professor Rex L. Brown, Assistant Professor Marlyn E. Clark, Assistant Professor W. Leighton Collins, Professor Herbert T. Corten, Research Assistant Professor Ralph E. Cramer, Research Associate Professor Todor Dimoff, Research Assistant Curtis W. Dollins, Research Assistant Professor Jasper O. Draffin, Professor Thaddeus M. Elsesser, Instructor Richard C. Elstner, Research Associate Melvin M. Enger, Professor and Dean of College of Engr., Emeritus Newton E. Ensign, Professor, Emeritus William N. Findley, Research Associate Professor Horatio M. Fitch, Assistant Professor Aldred M. Freudenthal, Research Consultant Eivind Hognestad, Research Associate Professor Russell S. Jensen, Research Assistant Professor Paul G. Jones, Associate Professor Clyde E. Kesler, Assistant Professor Henry L. Langhaar, Professor Wallace M. Lansford, Professor Herbert F. Moore, Research Professor, Emeritus William J. Putnam, Professor Herman J. Schrader, Research Professor William L. Schwalbe, Professor Fred B. Seely, Professor and Head of the Department, Emeritus Omar M. Sidebottom, Assistant Professor James O. Smith, Professor Montgomerie C. Steele, Research Associate Professor Ivan M. Viest, Research Assistant Professor Harry R. Wetenkamp, Research Assistant Professor Clyde E. Work, Assistant Professor Will J. Worley, Assistant Professor Digitized by the Internet Archive in 2013 http://archive.org/details/departmentoftheoOOuniv THE DEPARTMENT OF THEORETICAL AND APPLIED MECHANICS Early in the history of the College of Engineering it was recog- nized that the training of engineers required a thorough understanding of the principles of mechanics. Consequently, in about 1886, it was decided that analytical mechanics, resistance of materials, and hy- draulics should be taught as a related, compact group of subjects. This led to the organization of the Department of Theoretical and Applied Mechanics. The work of the Department is now of three types: undergraduate instruction, graduate instruction, and research. FACILITIES Most of the equipment, classrooms, and staff are located in Talbot Laboratory; the remainder are in the Transportation Building and the Car Wheel Laboratory. For convenience of designation, the facilities in Talbot Laboratory are divided into a number of specifically desig- nated areas, in accordance with the general nature of the work being conducted. The most unique of these areas are the large and small crane bays occupying the central portion of the building. These contain most of the large capacity equipment and are intended to be used for the experimental study of full-sized structural or machine components and assemblies. These areas and facilities are shared with the Department of Civil Engineering. Other special laboratories and their locations are : Concrete research Hydraulics and fluid mechanics Rolling load, railroad rails and joint bars Plastics, constant temperature and humidity Ground Floor Hydraulics and fluid mechanics First Floor Properties of materials _ . _. n , A , .. Second Floor Pnotoelasticity Fatigue of metals Creep of lead Third Floor Vibrations Metallography and photography Railway car wheels Car Wheel Laboratory The Department also has its own maehine shop and staff of technicians; thus the manufacturing of specially designed equipment, instruments, and specimens are under its direct control. An unusually large number of photographs of men prominent in the development of the science of mechanics may be seen in the cor- ridors of Talbot Laboratory. Below each photograph is a brief state- ment of the man's work. This collection is one of the most complete in the entire United States. There are many other facilities of a specialized nature through- out the University that are available to the staff; likewise, the De- partment cooperates with others when its specialized facilities are required. SCOPE OF ACTIVITIES On the undergraduate level, the Department functions as a service department for the College of Engineering; no undergraduate degree is granted, but all engineering students (as well as some non-engi- neers) are required to take courses in mechanics. In addition, ad- vanced undergraduate courses are offered as electives. On the graduate level, courses leading to the degrees of Master of Science and Doctor of Philosophy in Engineering are offered. During the past four years, 28 M.S. degrees and 18 Ph.D. degrees have been granted in Theoretical and Applied Mechanics. In addition, many graduate students from other departments take the courses as minors. A large proportion of the graduate students follow the desirable practice of pursuing their studies while serving as part-time assistants. Such assistantships are available for those who wish to gain additional experience in research, and a limited number are available on the teaching staff for those who wish to gain training and experience in instructional work. Research is considered to be a basic part of the educational pro- gram of the Department; strong emphasis is placed on the fact that the functions of teaching (on both the undergraduate and graduate levels) and research should go hand-in-hand for the most complete and effective development of students and staff. Research is carried on by most of those on the teaching staff and some teaching is done by those appointed to the research staff. GRADUATE STUDY In the programs for graduate students, emphasis is placed on formal course work and independent research. The latter preferably is a balanced combination of analytical and experimental work, but it may be predominantly one or the other. The formal courses listed below are those which are currently offered during the school year to advanced undergraduates and graduates. 311 Mechanical Vibrations 321 Advanced Mechanics of Materials 323 Advanced Laboratory in Materials Testing 326 Experimental Stress Analysis 334 Fluid Mechanics and Advanced Hydraulics 412 Vibration Analysis 416 Energy Methods in Mechanics of Materials 421 and 422 Mechanics of Materials 424 Properties of Engineering Materials 431 Applied Fluid Mechanics 432 Theory of Flow of Incompressible Fluids 436 Dimensional Analysis and Theory of Models 451 and 452 Theory of Elasticity with Application to Engineering Problems 461 and 462 Inelastic Behavior of Engineering Materials 491 and 492 Thesis, Master and Doctor, respectively 493 and 494 Special Problems These courses are taken not only by those majoring in mechanics but also by the large number of graduate students in other engineering departments who are minoring in mechanics. Staff and facilities are available to provide for individual study in areas of mechanics not covered by formal courses, and graduate students may undertake such special studies by registering in Theoretical and Applied Mechanics 493 and 494, "Special Problems." By making use of this provision and by selecting a suitable thesis subject, extensive graduate study and re- search can be carried on in almost every phase of mechanics. Gradu- ate students in mechanics also will find a wide variety of courses avail- able in other departments of the College or University. RESEARCH The high regard for the importanee of research work in the educa- tional program of the Department is evidenced by the fact that in ad- dition to a teaching staff active in research, about one-third of the full-time staff are on research appointments. These staff members work primarily, though not entirely, on investigations sponsored and financed by industrial organizations or governmental agencies. The research conducted by the teaching staff is usually financed by depart- mental funds. The Department does not contract with individuals or corpora- tions for the solution of a problem or the development of a product or process that is for the sole use or benefit of the sponsor. Thus the results of the investigations undertaken are made available to the engineering profession by virtue of publication in the many technical journals or as Bulletins of the Engineering Experiment Station.* The belief is generally held that both theoretical and experimental research should be conducted for a complete analysis of complex problems. If the project centers around carefully controlled experi- ments, the program must be carefully planned and critically evaluated or interpreted. A theory should be developed to explain the observed behavior and to assist in incorporating the ideas into the channels of learning and industrial applications. Where the work is theoretical or analytical, there is a need for verification of the assumed behavior; the basic assumptions should be associated with and interpreted in the light of the behavior of real engineering materials. Emphasis is also given to "interpretative writing," which establishes the significance of the great mass of theoretical and experimental knowledge available. One of the greatest needs of our age is to integrate and interpret re- search so that the engineer is able to make use of what is known. The accomplishment of research objectives often requires the de- sign and development of special apparatus and techniques. Conse- quently, the necessary machines and instrumentation are an integral part of the Department's work and such equipment can be observed in operation. Some of the more recent developments are as follows: 1. A 50,000-pound hydraulic universal testing machine which can be operated at a constant rate of loading, constant rate of strain, or other programmed cycle of load or strain. The controlled rates are achieved by means of a feed-back type servo-mechanism and the load and strain are recorded by an electronic recording mechanism. * A list of the bulletins may be obtained from the office of the Director of Engineering Information and Publications, Room 112 Civil Engineering Hall. 8 2. A torsion testing machine with a system of electrical, optical, and mechanical instruments and equipment for determining the influence of time and temperature on mechanical properties. Twisting moment, angle of twist, and elapsed time are continuously recorded for various strain rates and elevated temperatures. 3. A resonance type fatigue machine, electrically excited and con- trolled, and operating as a tuning fork. The specimen is suspended between two heavy cylindrical masses and subjected to vibratory bend- ing at the natural frequency. Some of the types of problems studied in recent years are listed below. No attempt is made to tabulate all investigations or to refer to them by titles; instead, only short, concise statements of the general nature of the work are given to facilitate judging the scope of the work. The projects are listed under the major headings of mechanics of solids (which is further subdivided), mechanics of fluids, and dynamics. PARTIAL LIST OF RESEARCH PROJECTS Mechanics of Solids Elasticity — Typical of the studies in this area are the following: Contact stresses between two elastic bodies subjected to both normal and tangential forces, including an experimental study of rollers to check the analytical results. An exact solution for the stresses and deflections of a helical coil spring with a rectangular cross section. A generalization of the Airy stress function to include cases of the membrane theory of shells. A method for analyzing the torsional-flexural buckling of columns based on the fundamental equations of elasticity and on the varia- tional principles of mechanics. The solution of some problems in plane elasticity using curvilinear coordinates. The behavior of thin-walled shells, utilizing either equations of equilibrium or energy methods, with application to the analytical and experimental determination of stresses and deformations in hollow propeller blades. Problems involving large and small deflections of plates, including small deflections of elastically supported rectangular plates, large de- flections of simply supported circular plates, and large deflections of annular and circular plates under uniform normal pressure. The stress and deflection of large glass plates, the developed theory being verified experimentally. Photoelasticity — A three-dimensional frozen stress technique using "Kriston" plastic for the study of stresses in railway car wheels due to normal and tangential loads. Inelastic Behavior of Members — The investigations of inelastic be- havior (plasticity) arc directed toward obtaining an understanding of the influence of small inelastic deformations on the behavior of ma- chine and structural elements. However, the limitations of analyses that assume an ideal plastic material are recognized. Typical of the studies are: Members subjected to tensile, bending, or twisting loads, combina- tions of these, and buckling of plates and eccentrically loaded columns. The mathematical analysis, verified by experiment, has treated the as- sumption of an ideal plastic material as a special case of the more general strain-hardening material. A portion of the experimental pro- gram has been directed towards exploring the validity of the mathe- matical analysis for mild steels which exhibit non-homogeneous time-sensitive behavior. Thick-walled cylinders have been studied ana- lytically and experimentally as an example of a more general state of stress. Experimental and analytical investigations of the inelastic behavior and strength of reinforced concrete members, including beams, eccen- trically loaded columns, footings, and slabs. The important influence of time on the behavior of eccentrically loaded columns, particularly in the region near the ultimate load, is being studied. The inelastic behavior (creep) of beams made of plastics. Several common types of load arrangement and dissimilar material behavior in tension and compression are being studied analytically and experi- mentally. Materials — Inelastic Deformation — The physical nature of inelastic deformation of metals is being studied from the point of view of the non-homogeneous nature of inelastic deformation. The non-homoge- neity which exists at the various levels of association of matter due to the behavior and interaction of ordered and unordered phases offers a qualitative explanation of the observed time- and temperature-sensi- tive deformation and provides a basis for forming theoretical hypothe- ses that have been studied experimentally. Examples of this type of study include: 10 The nature of strain hardening by fragmentation, the yielding of low carbon steel by the formation of Liiders bands, the significance of a stress gradient upon the initiation of inelastic deformation, the nature and significance of residual stresses caused by inelastic deformation. The range of application of mechanical equation of state for plastics. A correlation of the static, dynamic and creep behavior of con- crete members. The creep behavior, including ductility and stress-rupture charac- teristics, of various lead alloys used for cable sheathing. Materials — Fracture — The study of fracture, regardless of its type, is usually approached from the point of view of being the limiting state of inelastic deformation. The nature of progressive fracture (fatigue) is being studied in metals, plastics, and concrete. Examples of this type of study include: For metals, development of theories of fatigue damage and their study by appropriate experimental techniques, including use of the electron microscope. Investigation of the influence of metallurgical structure, rest periods, recrystallization, residual stress, strain harden- ing, state of stress, variable stress amplitude, notch-sensitivity, and size and shape effects are some of the parameters which are considered in the attempt to determine the fundamental statistical nature of fatigue. Various plastics and laminates under controlled conditions of temperature and humidity. Bending, torsional and direct stresses, as well as combinations of them have been used in the repeated load studies. Concrete beams subjected to repeated bending loads to study the mechanism of failure and the effect of certain selected variables on the fatigue strength. The influence of high and low temperature, rate of strain, state of stress, and stress concentration upon fracture of metals subjected to tensile and torsional loading. The fracture of railway car wheels subjected to severe thermal cycling due to brake applications. The studies are both theoretical and experimental and include the effects of changes in metallurgical structure. Investigation of the causes and methods of prevention of various types of progressive fracture of railroad rails and joint bars. 11 Mechanics of Fluids The following problems have been investigated for an ideal fluid: Two-dimensional potential flow in a gravitational field with a known free surface, pressure surges in long pipe lines due to water hammer, and the diffraction of water waves by ocean structures such as islands, breakwaters, and harbors. The behavior of a viscous fluid, including thermodynamic effects, and the application to the problem of rolling of glass plates. An experimental investigation of back-water profiles in open chan- nels, including two different degrees of roughness and two different channel cross sections. An analytical and experimental study of laminar flow and the criti- cal Reynold's number for change to turbulent flow in open channels. A study of the behavior of small centrifugal pumps to determine, both analytically and experimentally, the effect of various shaped vanes and impellers on the output and efficiency at various speeds. Dynamics Among the problems related to the vibration of structures and ma- chines are the following: Natural frequency of load-carrying columns, bending vibration of a rotating blade, and the bending vibration of a beam with general boundary conditions, considering shear and rotary inertia. The concept of complex damping applied to the forced vibrations of crankshafts and airplane wings. Nonlinear torsional vibration in two degrees of freedom. A single degree of freedom system involving a single mass with various combinations of nonlinear springs and dampers. 12 PRESSBOARD PAMPHLET BINDER Manufactured by jGAYLORD BROS. Inc. Syracuse, N.Y. Stockton, Calif.