_STP_1303-1997.pdf

STP 1303 Applications of Automation Technology to Fatigue and Fracture Testing and Analysis:Third Volume A.A.Braun and L.N.Gilbertson,Editors ASTM Publication Code Number(PCN):04-013030-30 ASTM 100 Barr Harbor Drive West Conshohocken,PA 19428-2959 ISBN:0-8031-2416-3 ASTM Publication Code Number(PCN):04-013030-30 Copyright?9 1997 AMERICAN SOCIETY FOR TESTING AND MATERIALS,West Conshohocken,PA.All rights reserved.This material may not be reproduced or copied,in whole or in part,in any printed,mechanical,electronic,film,or other distribution and storage media,without the written consent of the publisher.Photocopy Rights Authorization to photocopy items for internal,personal,or educational classroom use,or the internal,personal,or educational classroom use of specific clients,is granted by the American Society for Testing and Materials(ASTM)provided that the appropriate fee is paid to the Copyright Clearance Center,222 Rosewood Drive,Danvers,MA 01923;Tel:508-750-8400;online:http:/ Review Policy Each paper published in this volume was evaluated by two peer reviewers and at least one editor.The authors addressed all of the reviewers comments to the satisfaction of both the technical editor(s)and the ASTM Committee on Publications.The quality of the papers in this publication reflects not only the obvious efforts of the authors and the technical editor(s),but also the work of these peer reviewers.The ASTM Committee on Publications acknowledges with appreciation their dedication and contribution of time and effort on behalf of ASTM.Printed in Scranton,PA October 1997 Foreword The Third Symposium on Applications of Automation Technology to Fatigue and Fracture Testing and Analysis was presented in Norfolk,Virginia on 14 November,1995.The sym-posium was held in conjunction with the 13-16 November 1995 meeting of ASTM Committee E8 on Fatigue and Fracture,which sponsored the symposium.Arthur A.Braun,MTS Systems Corporation,and Leslie N.Gilbertson,Zimmer,Inc.,served as chairmen of the symposium and editors of the resulting publication.Contents Overview 1 DATA ACQUISITION Networked Data Acquisition Systems for Strain Data Coilection-G.MCLEAN,B.PRESCOTT,AND M.ELLENS 5 Fatigue and Reliability Assessment Incorporating Computer Strain Gage Network Data-M.ELLENS,J.PROVAN,G.MCLEAN,AND M.SANDERS 19 Cycle-by-Cycle Compliance Based Crack Length Measurement-R.SUNDER 33 Feasibility Study of Alternating Current Potential Drop Techniques for Elastic-Plastic Fracture Toughness Testing-R.TREGONING 43 S IMULATION Fatigue Life Contours from Elastic FEM Considering Muitiaxial Plasticity-T.E.LANGLAIS,J.H.VOGEL,D.F.SOCIE,AND T.S.CORDES Computer Modeling and Simulation in a Full-Scale Aircraft Structural Test Laboratory-R.L.HEWIar AND F.J.ALBRIGHT TEST CONTROL Computer-Controlled High Strain Rate Compression Test System-c.s.VENKATESH,R.V.PRAKASH,AND R.SUNDER Adaptive PID Control of Dynamic Materials-Testing Machines Using Remembered Stiffness-c.E.HINTON Characteristics and Automated Control of a Dual-Frequency Servohydraulic Test System-K.REIFSNIDER,S.CASE,AND L.MOSIMAN Materials Characterization Using Calculated Control-J.CHRlSTIANSEN,R.L.T.OEHMKE AND E.A.SCHWARZKOPF Control of a Biaxial Test Using Calculated Input Signals and Cascade Control-F.J.ALBR1GHT AND L E.JOHNSON 69 81 99 111 120 131 147 STP1303-EB/Oct.1997 Overview This is the third symposium on Applications of Automation Technology to Fatigue and Fracture Testing and Analysis.The papers in this book exemplify the typical evolution of computers and their applications.The simpler applications of past years are becoming more sophisticated,the hardware is becoming smaller and more powerful,and computers are doing things now that werent even considered previously.Data acquisition was a natural application of computers,even before the invention of the microprocessor.The microprocessor has made data acquisition application in fatigue applica-tions ubiquitous.The paper Networked Data Acquisition Systems for Strain Data Collection,by G.McLean,B.Prescott,and M.Ellens,brings computer networking to the field of portable fatigue data acquisition.With an innovative application of networking technology they have created a very small modular expandable data acquisition,which can collect field strain data,pre-process it,and forward it for further analysis and storage.This permits use of the system on applications where previous larger systems would have inhibited the natural use of the device under study.In the paper Fatigue and Reliability Assessment Incorporating Computer Strain Gage Network Data,by M.Ellens,J.Provan,G.McLean,and M.Sanders,the authors made use of the system to make fatigue life prediction on the unique application of racing mountain bicycles.The paper Cycle-by-Cycle Compliance Based Crack Length Measurement,by R.Sunder,points up one of the problems related to the ubiquitous nature of computer data acquisition.There is a natural tendency to assume that newer and faster computers