D Radaj, C M Sonsino and W Pricke. Fatigue assessment of welded joints by local approaches

Transcription

1 D Radaj, C M Sonsino and W Pricke Fatigue assessment of welded joints by local approaches Second edition

2 Foreword Preface Author contact details Introduction 1.1 Fatigue strength assessment of welded joints Present state of the art Demands from industrial product development 1.2 Basic aspects of assessment procedures Multitude of parameters governing fatigue failure Global and local approaches of fatigue strength assessment Complications of local approaches for welded joints Survey of subject arrangement xv xvii xix Nominal stress approach for welded joints Basic procedures Principles of the nominal stress approach Procedures for welded joints Analysis tools Books, compendia, guidelines and design codes Basic formulae Permissible stresses and design S-N curves Influence of mean and residual stresses Influence of stress multiaxiality Influence of plate thickness, weid dressing and environment 27

3 VI Analysis Basic Normalised Fatigue Evaluation Further Definition Hot Endurable Principles Alternative Structural Specific General Contents procedures spot tools strength rules variants survey stress strain of structural stress of definitions S-N - the for hot endurable structural concentration and approach reduction of curves finite spot or structural stress relevant strains stresses element of structural approach hot as factors stress in guidelines proposed weid spot factors modelling stresses for for for seam-welded structural by the non-tubular root or stress concentration strain strains Xiao- Dong Haibach fatigue evaluation approach joints Yamada stress joints approach factors joints

4 Demonstration Basic Analysis Endurable Welded Notch Fatigue Structural Principles Fictitious Modified Highly General Critical procedures VII tools stressed joints distance tubular bridge survey notch and hot multiaxial structural concentration analysis examples factors in variants spot girder volume rounding joints and based approach ship butt for structures of stresses with -assessment of approach various welded joints the cope factors inotch tubular -procedure joints - the holes strains structural weid of -Dong weid joints Contents and basic Xiao- non-tubular stress strain root toe refined links weided design fatigue to Yamada approach guidelines procedures joints structural joints approaches stresses 89 91

5 VIII Basic Design-related Analysis Demonstration Web Tensile Further Assessment Fatigue Principles Peculiarities Welded End-to-shell Stiffener-to-flange Effect Typical Early Comprehensive Special Short-crack Applications Stress Girth Gusseted Laser Comparison Crack Contents Notch procedures stiffener butt application beam relief of propagation strain tools specimen formulae life strength vehicle refinements geometrical shell of welds of behaviour procedure groove with joint the of notch examples approach fillet-welded stress-relieved butt-welded structure basic for frame the exposition of crack notch for with seam-welded of early joint wider unusual approach the of boiler multiaxial weid design containment corner longitudinal propagation strain the at applications Ifor and evaluations section ship loading joints parameters approach of tubular cruciform manufacture seam-welded the press frame joints fatigue with girder types modes joint seam-welded detail ure approach joints corner vessel joints joints butt-welded residual attachment stresses joints 4.3

6 Demonstration Analysis General Basic Procedures I-integral Butt-welded Notch General Methods Material Residual Particular Longitudinal Lap Refined Formal Principles Plastic Strain Fatigue Endurable Crack Initial Cruciform Stress procedures joints intensity rise propagation energy shape and stress considerations notch tools IX aspects limit crack analysis survey parameters of stress and final notch corner joints intensity expressed front stress and examples density results propagation variants cover T-joints of effects factors and crack of crack stress transverse presentation of life equations intensity longitudinal notches results relevant of plate for fillet size factors for path of intensity by crack approach corner blunt sharp fillet-welded crack the notch joints welds factor at references for approach notches propagation factors stress forjoints seam-welded of Contents joints 296 corner intensity determination fillet-welded attachment notches factors joints 7.1

7 x Subject Method-related Basic Notch Endurable Fatigue Principles Weak Application Link Comparison Crack Significance Contents Structural Local procedures to crack matter points approaches propagation stress test strength theof corner and stress crack hot propagation results of and the of conc1usions fatigue the potential spot investigation analysis assessment crack elastic-plastic strain propagation notch or structural life applied strain terms assessment propagation according concentration notch I-integral strain models and of stress the of based to approach stress energy hot notch a to or seam-welded of on spot approach strain atfor stress spot-welded tubular joint spot-welded stress strain EU British concentration and weid notch fillet-welded density approach Report similar toe approach measurement strains Standard of fillet-welded joints lap factors similarjoints lap joints 7.3.4

8 Analysis Demonstration Nominal WeId Elastic-plastic Large Endurable Fatigue Spot-welded Laser Modelling Computation General Structural Buckling Computer spot be deflections tools XI life am survey theory fatigue stress strain forces codes of structural assessment welded - engine axle weid and examples deformation non-linear structural endurable of analysis measurement by suspension decomposition forces spot pillar-to-rocker weid support correlation fatigue stresses supporting resultant welds stress structural and spots weid plate nugget assessment member arm stresses weid subjected of weid weid laser strains spots forces of at car spots stresses at behaviour weid weid spots beam at weid at evaluation Contents spot to cross-tension connection resultant or body tensile-shear compiled weids at strain spot compi1ed GMA strains spots design patterns weids spots comparison forces bycompiled Maddox Rupp loading by Radaj

9 XII Basic Analysis Comparative I-integral Principles Weak Early Links Endurable Equivalent Laser Stress General Spot-welded Contents procedures stress beam-welded to points intensity tools survey other and of stress evaluation intensity -notch hat H-shaped cross-tension tensile-shear double-cup the ofnugget fatigue approaches factors the and section stress intensity stress tensile-shear basic factor rotation assessment formulae of specimens approach spot-welded of lap intensity definitions and factors solutions stress joints variants spot-welded and based under intensity with for459 and on onstress and similar 433 large pe structural unequal dissimilar nominal similar application factors lap intensity mixed approach ei-tension joints deflections mode specimens plate structural factors stresses materials relevance specimens conditions thickness stresses

10 Basic Analysis Limitations Potential Comprehensive Significance, Notch- Fatigue Principles Weak Residual Hardness General Modelling procedures points XIII tools and of assessment survey stress distribution of local examples crack-based local the and limitations modelling distribution approaches notch potential through presented stress, spot-welded examples approaches and of in improved simplified conventional notch crack the by by potential Nykänen crack notch Henrysson Lawrence Sheppard strain joints for ofspot-welded loeal Contents spot-welded approaehes and stress notch strain small-size propagation crack similar stress approach propagation notch joints approach lap approach joints approaches