Steel Buildings in Europe

Part 4: Detailed Design of Portal Frames 4 - v Contents Page No FOREWORD iii SUMMARY vii 1 INTRODUCTION 1 1.1 Scope 1 1.2 Computer-aided design 1 2 SECOND ORDER EFFECTS IN PORTAL FRAMES 3 2.1 Frame behaviour 3 2.2 Second order effects 4 2.3 Design summary 5 3 ULTIMATE LIMIT STATE 6 3.1 General 6 3.2 Imperfections 8 3.3 First order and second order analysis 13 3.4 Base stiffness 16 3.5 Design summary 18 4 SERVICEABILITY LIMIT STATE 20 4.1 General 20 4.2 Selection of deflection criteria 20 4.3 Analysis 20 4.4 Design summary 20 5 CROSS-SECTION RESISTANCE 21 5.1 General 21 5.2 Classification of cross-section 21 5.3 Member ductility for plastic design 21 5.4 Design summary 22 6 MEMBER STABILITY 23 6.1 Introduction 23 6.2 Buckling resistance in EN 1993-1-1 24 6.3 Out-of-plane restraint 26 6.4 Stable lengths adjacent to plastic hinges 28 6.5 Design summary 31 7 RAFTER DESIGN 32 7.1 Introduction 32 7.2 Rafter strength 32 7.3 Rafter out-of-plane stability 33 7.4 In-plane stability 37 7.5 Design summary 37 8 COLUMN DESIGN 38 8.1 Introduction 38 8.2 Web resistance 38 8.3 Column stability 38 8.4 In-plane stability 41 8.5 Design summary 41 9 BRACING 42 9.1 General 42