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Creep in Structures: Colloquium Held at Stanford University, California July 11–15, 1960 PDF

383 Pages·1962·14.219 MB·English
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Preview Creep in Structures: Colloquium Held at Stanford University, California July 11–15, 1960

INTERNATIONAL UNION OF THEORETICAL AND APPLIED MECHANICS CREEP IN STRUCTURES COLLOQUIUM HELD AT STANFORD UNIVERSITY, CALIFORNIA JULY 11-15, 1960 EDITED BY NICHOLAS J. HOFF WITH 156 FIGURES S PR I N GER -VER LA G BERLIN / GÖTTIN GEN / HEIDELBERG 1962 ISBN 978-3-642-86016-4 ISBN 978-3-642-86014-0 (eBook) DOl 10.1007/978-3-642-86014-0 AAIlllee RReecchhttee,, iinnssbbeessoonnddeerree ddaass ddeerr ÜUbbeerrsseettzzuunngg iinn ffrreemmddee SSpprraacehheenn,, vvoorrbbeehhaalltteenn OOhhnnee aauussddrriüicckklliicchhee GGeenneehhmmiigguunngg ddeess VVeerrllaaggeess iisstt eess aauucehh nniicchhtt ggeessttaatttteett,, ddiieesseess BBuucchh ooddeerr TTeeiillee ddaarraauuss aauuff pphhoottoommeecchhaanniisscchheemm WWeeggee ((PPhhoottookkooppiiee,, MMiikkrrookkooppiiee)) ooddeerr aauuff aannddeerree AArrtt zzuu vveerrvviieellffiäillttiiggeenn AAllll rriigghhttss rreesseerrvveedd.. NNoo ppaarrtt ooff tthhiiss bbooookk mmaayy bbee rreepprroodduucceedd iinn aannyy ffoorrmm,, bbyy mmiiccrrooffiillmm oorr aannyy ootthheerr mmeeaannss,, wwiitthhoouutt ppeerrmmiissssiioonn iinn wwrriittiinngg ffrroomm tthhee ppuubblliisshheerrss ©© bbyy SSpprriinnggeerr--VVeerrllaagg OORRGG..,, BBeerrlliinn//GGö6ttttiinnggeenn//RReeiiddeellbbeerrgg 11996622 SSooffttccoovveerr rreepprriinntt ooff tthhee hhaarrddccoovveerr 1155tt eeddiittiioonn 11996622 LLiibbrraarryy 0011 CCoonnggrreessss CCaattaalloogg CCaarrdd NNuummbbeerr:: 6622--1166117700 Foreword The Colloquium on Creep in Structures was organized as part of the activities of the International Union on Theoretical and Applied Mecha nies. It was supported financiaHy by IUTAM, as weH as by the National Science Foundation, Washington, D. C., U. S. A. The Scientific Commit tee charged with the work of organization consisted of the foHowing persons: NICHOLAS J. HOFF, Stanford University, Stanford, California, Chair man FOLKE K. G. ODQVIST, Royal Institute of Technology, Stockholm, Sweden, Vice-Chairman R. MAZET, Office National d'Etudes et de Recherehes Aeronautiques, Chatillon-sous-Bagneux, France Y. N. RABOTNOV, Academy of Sciences, Novosibirsk, U. S. S. R. SHUJI TAIRA, Kyoto University, Kyoto, Japan. The details of the organization of the sessions were entrusted to the Local Committee consisting of the following persons: MAX ANLIKER W. H. HORToN K. BINFORD B. LEMPRIERE C.C.CHAO L. NICKEL W. G. FLÜGGE In order to insure good discussion and, in general, a broad exchange of ideas among the participants in the meeting, the number of persons invited to attend was kept to a minimum. Participants not living in the Stanford area were housed in Donner House of Stern Hall on the Stanford campus, and were served meals in the dining room of Donner House. The speakers and observers started to arrive on July 9 and the last ones left on July 18. All the scientific sessions were held in the Engineering Building of Stanford University, where the Colloquium was officially opened at 9.00 A. M. on July 11. The program of the .meeting was as follows: Monday, July 11 9.00 A. M.: Official Opening 01 Colloquium Ohairman: DONALD L. PUTT, Lt. Gen. (ret.) U. S. Air Force; Chairman Advisory Committee, Industrial Affiliates of Stanford University in Aeronautics and Astronautics Speakers: NICHOLAS J. HOFF, Chairman, Colloquium on Creep in Structures FREDERICK E. TERMAN, Provost, Stanford University IV Foreword JOSEPH M. PETTIT, Dean, School of Engineering, Stanford University FOLKE K. G. ODQVIST, President, International Union on Theoretical and Applied Mechanics 9.30 A. M.: Linear Viscoelasticity Chairman: OLEG D. SHERBY, Stanford University E. H. LEE and A. H. CORNELIUSSEN, Brown University, Providence, Rhode Island, U. S. A.: The influence of viscoelasticity on stress distribution H. H. HrLTON, University ofiliinois, Urbana, Illinois, and E. L. W ALSH, Boeing Aircraft Co., Seattle, Washington, U. S. A.: Torsional Response of Linear Viscoelastic Plates Subjected to Thermal Stresses 2.00 P. M.: Stress Distribution Chairman: HAROLD LIEBOWITZ, Office of Naval Research, U. S. Navy S. A. PATEL and B. VENKATRAMAN, Polytechnic Institute of Brooklyn, Brooklyn, New York, U. S. A.: On the creep stress analysis of some structures A. PHILLIPS, Yale University, New Haven, Connecticut, U. S. A.: The shear center 'in creep of beams of thinwalled open cross section 1i.00 P. M.: Reception in honor of speakers given by Dr. and lVIrs. N. J. HOFF at 782 Esplana da Way, Stanford, California Tuesday, July 12 9.00 A. M.: Creep Laws Chairman: JAMES J. MURRAY, Office of Ordnance Research J. MARIN, Pennsylvania State University, University Park, Pennsyl vania, U; S. A.: Mechanics of creep and combined stresses S. TAIRA, Kyoto University, Kyoto, Japan: The lifetime of structures subjected to varying load and temperature E. T. ONAT and T. T. W ANG, Brown University, Providence, Rhode Island, U. S. A.: The effect öf incrementalloading on creep behavior of metals Wednesday, July 13 9.00 A. M.: Large Deformations Chairman: JOHN A. JOHNSON, Lockheed Missiles and Space Division F. K. G. ODQVIST, Royal Institute of Technology, Stockholm, Sweden: Applicability of the elastic analogue to creep problems of plates, membranes and beams J. HULT, Royal Institute of Technology, Stockholm, Sweden: on canning problems in creep 12.30 P. M.: Excursion by Chartered Bus v Foreword Thursday, July 14 9.00 A. M.: Disks and Plates Chairman: J. N. GOODIER, Stanford University J. F. BESSELING, Institute of Technology, Delft, Holland: Investiga tion of transient creep in tubes and disks under radially symmetrie loading A. M. WAHL, Westinghouse Electric Corporation, Pittsburgh, Pennsyl vania, U. S. A.: A comparison of flow criteria applied to elevated temperature creep of rotating disks with consideration of the transient condition T. H. LIN, University of California, Los Angeles, California, U. S. A.: Bending of a circular plate with non-linear and strain-hardening creep 2.00 P. M.: Cylindrical Shells Chairman: WILHELM FLÜGGE, Stanford University H. PORITSKY, The General Electric Company, Schenectady, New Y ork, U. S. A.: Creep in cylindrical shells C. R. CALLADINE, The English Electric Company, Ltd., Whetstone, Leicestel', England: The creep of a wrinkle 6.00 P. M.: Social Hour at Adobe Creek Lodge, followed by Banquet at 7.00 p. m. Toastmaster: NIOHoLAs J. HOFF Quest Speaker: RONALD SMELT: "Satellite Environment" Friday, July 15 9.00 .A. M.: Columns Chairman: RALPH H. LONG, National Science Foundation R. L. CARLSON and W. W. BREINDEL, BatteIle Memorial Institute, Columbus, Ohio, U. S. A.: On the mechanics of column creep B. M. LEMPRIERE, Stanford University, Stanford, California, U. S. A. : Comparison of ranges of applicability of predictions of creep buckling time M. ZYOZKOWSKI, Technical University of Krakow, Krakow, Poland: Geometrically non-linear creep buckling of bars 2.00 P. M.: Assemblies-Torsional Buckling-Damping Chairman: F. K. G. ODQVIST, Royal Institute of Technology, Stockholm, Sweden R. MAZET, Office National d'Etudes et de Recherehes Aeronautiques, Chatillon-sous-Bagneux (Seine), France: Sur un modele apte a traduire le fluage sous charge constante des assemblages A. H. CHILVER, Cambridge University, Cambridge, England: Some simple models for torsional creep buckling N. J. HOFF, Stanford University, Stanford, California, U. S. A.: Dam ping of the vibrations of a coiled spring due to creep 4.45 P. M.: Closure VI Foreword A list of the participants and their affiliations folIows: Professor J. F. BESSELING Institute of Technology, Delft, Holland Professor R. J. BOLLARD California Institute of Technology Mr.E.B.BoREK Marquardt Corporation Dr. J. M. BROWN Hughes Aircraft Company Dr. C. R. CALLADlNE English Electric Company, Ltd. Mr. R. L. CARLSON Battelle Memorial Institute Dr. K. T. CHANG AiResearch Manufacturing Company, Division of Garrett Corporation Dr. ROBERT A. CHASE United Technology Corporation Dr. A. H. CHILVER Cambridge University, Cambridge. England Monsieur H. DE l'ESTOILE Service Technique Aeronautique, French Air Force Monsieur E. FAGE Service Technique Aeronautique, French Air Force Dr. ROBERT P. FELGAR Space Technology Laboratories, Inc. Professor WILHELM FLüGGE Stanford University Professor Y. C. FuNG California Institute of Technology Dr. ROBERT GATTS General Electric Company Professor N ORMAN GOODIER Stanford University Mr. CHARLES A. HERMACH Ames Research Center NASA Professor H. H. IIILTON University of Illinois ProfE'ssor N. J. HOFF Stanford University Dr. OSCAR HOFFMAN Lockheed Missiles and Space Division Dr.JANHuLT Royal Institute of Technology, Stockholm, Sweden Dr. WILLIAM E. JAHSMAN Stanford University Mr. JOHN A. JOHNSON Lockheed Missiles and Space Division Professor MAKOTO KrKUKA WA Osaka University, Osaka, Japan Mr. BERTRAM KLEIN Convair, Division of General Dynamics Corpo ration Professor ALBERT KOBAYASHI Boeing Airplane Company, Aero Space Division Professor E. H. LEE Brown University Mr. B. M. LEMPRIERE Stanford University Dr. HAROLD LIEBOWITZ Office of Naval Research Professor T. H. LIN University of California at Los Angeles Professor Hsu Lo Purdue University Dr. RALPH H. LONG National Science Foundation Professor J OSEPH MARIN Pennsylvania State University Mr. H. G. MCCOMB Langley Research Center, NASA Mr. JAMES J. MURRAY Office of Ordnance Research, U. S. Army Dr. J. MURZEWSKI Institute of Technology, Krak6w, Poland Dr. WILLIAM NACHBAR Stanford University " . Professor F. K. G. ODQVIST Royal Institute of Technology, Stockholm, Sweden Professor E. T. ONAT Brown University Professor S. A. P ATEL Polytechnic Institute of BrooklYll: Professor ARIS PHILLIPS Yale University Professor YVES PIRRONEAU University of Nantes, France Dr. H. PORITSKY General Electric Company Lt. GEN. D. L. PUTT Stanford University Professor CEDRIC W. RICHARDS Stanford University Foreword VII Dr. CARLO RIPARBELLI General Atomic, Division of General Dynamics Corporation Dr. E. E. SECHLER California Institute of Technology Professor OLEG SHERBY Stanford University Mr. RONALD SMELT Stanford University Dr. W. STUIVER IBM Research Laboratory Professor Y. SUEZAWA Institute of Technology, Tokyo, Japan Professor S. TAIRA Kyoto University, Kyoto, Japan Dr. KICHINOSUKE TANAKA Kyoto University, Kyoto, Japan Provost FREDERICK TERMAN Stanford University Dr. SITARAMARAO V ALLURI California Institute of Technology Professor B. VENKATRAMAN Polytechnic Institute of Brooklyn Dr. A. M. W Am. Westinghouse Electric Corporation Professor HARRY WILLIAMS Stanford University Dr. JOHN ZICKEL Aerojet-General Corporation Dr. M. ZYCZKOWSKI Technical University of Krak6w, Krak6w, Poland To provide relief from the scientific·activities, a bus trip was organized for the afternoon of July 13. The 17 persons who took part in the excur sion were shown some of the scenic beauties of California and some of the oldest buildings, dating back to the days of Spanish rule, in Monterey ld in Carmel. The banquet was held at Adobe Creek Lodge in a pleasant setting among the steep foothills of the Coast Range. It was attended by 58 per sons, including many of the wives of the participants. In the after-dinner talk, Mr. RONALD SMELT, Chief Scientist of the Lockheed Missiles and Space Division and a lecturer in the Department of Aeronautical En. gineering of Stanford University, gave an interesting report on efforts to investigate the environment in which satellites travel. Although most informative, the talk was given in a manner understandable to the ladies present; it was illustrated by an interesting sound film . .T he.sessions took place in accordance with the prearranged program, except that the paper written by Professor MAZET was delivered by Monsieur HUGUES DE L'EsTOILE of the Service Technique Aeronautique of the French Air Force, and that the titles of some of the papers were changed slightly. The meeting clo§led in the afternoon of July 15. N. J. HOFF voiced the thanks of Stanford University for the work done by the participants, and FOLKE K. G. ÜDQVIST, President of the International Union for Theoretical and Applied Mechanics, expressed the appreciation of the participants for the hospitality shown them by Stanford. Speakers and discussors enjoyed the possibility offered to them for the discussion of problems caused by creep in structures. It is hoped that readers of these proceedings will derive equal benefits from this volume. Stanford University, California N.J. Hoff Contents Page Foreword ................ . III Stress Distribution Analysis for Linear Viscoelastic Materials. By A. H. CORNELIUSSEN and E. H. LEE . . . . . . . . 1 Torsional Response of Linear Viscoelastic Plates Subjected to Thermal Stresses. By HARRY H. HILTON and EDW.ARD L. WALSH . . . . . . . . . . . 21 On the Creep Stress Analysis of some Structures. By SHARAD A. PATEL and B. VENKATRAMAN . 43 The ShearCenter in Creep of Beams of Thin-Walled Open Cross Section. By ARIS PHILLIPS . . . . . . . . . . . . . . . . . . . . . . 65 Mechanics of Creep and Combined Stresses. By J OSEPH MARIN . . . 79 Lifetime of Structures Subjected to Varying Load and Temperature. By SHUJI TAIRA ................•... 96 The Effect of Incremental Loading on Creep Behavior of Metals. By E. T. ONAT and T. T. WANG. . . . . . . . . . . . . . 125 Applicability of the Elastic Analogue to Creep Problems of Plates, Membranes and Beams. By FOLKE K. G. ODQVIST. . . . . . . . . . . . . ... 137 Oil Canning Problems in Creep. By JAN HULT. . . . . . . . . . . .. . 161 Investigation of Transient Creep in Thick-Walled Tubes under Axially Sym- me~ric Loading. By J. F. BESSELING ................ 174 A Comparison of Flow Criteria Applied to Elevated Temperature Creep of Rota- ting Discs with Consideration of the Transient Condition. By A. M. WAHL 195 Bending of a Plate with Non-Linear Strain-Hardening Creep. By T. H. LIN 215 Effect of Creep on Stresses in Cylindrical Shells. By H. PORITSKY 229 On the Creep of a Wrinkle. By C. R. CALLADINE. . . . . . . . 245 On the Mechanics of Column Creep. By R. L. C.ARLSON and W. W. BREINDEL 272 Comparison of Ranges of Applicability of Predictions of Creep Buckling Time. By BRIAN M. LEMPRIERE. . . . . . . . . . . . . . . . . . . . . 291 Geometrically No~-Linear Creep Buckling of Bars. By MICHAL ZYCZKOWSKI 307 Sur un modele apte a traduire le fluage sous charge constante des structures. Par R. MAZET. . . . . . . . . . . . . . . . . . . . . . . 326 Some Simple Models for Torsional Creep Buckling. By A. H. CHILVER ... 339 Damping of the Vibrations of a Coiled Spring Due to Creep. By N. J. HOFF 355 Subject index . . . . . . . . . . . . . . . . . . . . . . . . . . 374 Stress Distribution Analysis for Linear Viscoelastic Materials! By A. H. Corneliussen and E. H. Lee Brown University, Providence, Rhode Island, USA Abstract The formulation of the differential or integro-differential equations governing the quasi-static stress analysis problem for linear viscoelastic bodies is considered, with particular reference to the initial conditions associated with sudden loading. If classical methods of solving the diffe rential equations, such as the LAPLACE transform or integrating factor, are used, the need to evaluate the initial conditions after load applica tion at t = 0+ presents difficulties. These can be avoided by working with the lower limit t = 0-, before load application, when the body is still undisturbed, and, in the case of direct integration of the equations, delta functions and their derivatives must then be incorporated into the ana lysis. Examples of both methods of approach are contrasted. The stress distribution in a spinning hollow circular cylinder with annihilating inner cavity is evaluated as an example which does not fall within the scope of the LAPLACE transform method of analysis. The procedures are justified through the application of the corresponding integral operators. 1. Introduction In analysing the stress distributions in viscoelastic bodies, a system of partial differential equations or integro-differential equations con taining derivatives or integrals with respect to both the space variables and the time must be solved [1,2]2. It is common to consider applied surface tractions in the form of the HEAV ISIDE step function in the time variable: H(t) = 0, t< 0 (1.1) = 1, t> 0 1 Sponsored under Department of Defense Contract DA-19-020-0RD-4750, between the Office of Ordnance Research, US Army, and Brown University. 2 Numbers in square brackets refer to the bibliography at the end of the paper. 1 Hoff, C.reep in Structures 2 A. H. CORNELIUSSEN and E. H. LEE this being the mathematical idealisation of a rapidly applied load. Many such problems can be adequately treated on the basis of quasi-static theory, in which the inertia forces associated with the deformation of the body can be neglected in comparison with the applied forces. In such an analysis the effect of the surface tractions, applied suddenly at t,= 0, is feIt instantaneously throughöut the body. Thus, even though the body was unstressed for t <0, the dependent variables, the stress and strain components, may have non-zero initial values after the instantaneous distribution of the loads. These values will be associated with the time t = 0+, the situation just before load applieation being assoeiated with t = 0-. Initial time derivatives of first and higher orders will in general also be non-zero at t = 0+. Thus the solution of the system of differential or integro-differential equations must be sought for t >0, with non-zero initial values at t = 0+. Moreover, these values are not known apriori. For an isotropie linear viscoelastie body, the stress-strain relations eontain two pairs of linear operators whieh are analogous to the two elastie eonstants required to specify linear isotropie elastieity. For eon venienee, separating the shear and dilatational effeets, the viseoelastie law s take the form: (1.2) (1.3) where P, Q, P', Q' are linear differential or integral operators; (fij' Cu the stress and strain tensors respectively, and 8ij andeijtheeorrespond ing deviators whieh represent shear effeets. The summation eonven tion for repeated suffixes is utilized, so that (1.3) is the relation between the average hydrostatic tension, (fiif3, and the dilatation, cw If a rela tion of type (1.2) or (1.3) between a stress component (f and astrain component c corresponds to a viscoelastic model with a finite number of springs and dashpots, it can be represented by differential operators of finite order, for example: (1.4) General linear viseoelastieity ean be represented in terms of the ereep eomplianee J (t), by the integral relation: e Jt c(t)= J(t-r:)e:dr: (1.5) - co and if the material is undisturbed for t< 0, this ean be written in the form: e Jt e(t)= J(t-r:)~adr:. (1.6) o cl'!:

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Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.