Introduction to cable roof structures
Buchholdt, H. A.
Introduction to cable roof structures - Ed.2 - London Thomas Telford 1999 - xiv,285p.
CONTENTS Preface to the second edition xi Preface to the first edition xiii 1 Structural systems 1 Introduction 1 Simply suspended cable structures 2 Pretensioned cable beam structures 4 Pretensioned cable net structures 7 Pretensioned cable grid structures 8 General structural characteristics 11 Bibliography 13 2 The nature and statistical properties of wind 14 Introduction 14 The nature of wind 15 Mean wind speed and variation of mean velocity with height 17 Statistical properties of the fluctuating velocity component of wind 19 Variance and standard deviation 20 Auto-correlation and auto-covariance functions 21 Spectral density functions of longitudinal velocity fluctuations 21 Cross-correlation and cross-covariance functions 24 Cross-spectral density and coherence functions for longitudinal velocity fluctuations 25 The probability density function and peak factor for the fluctuating component of wind26 The cumulative distribution function 28 Pressure, drag and lift forces 28 References 32 3 The nature and statistical properties of earthquakes 33 Introduction 33 Types and propagation of seismic waves 33 Recording of earthquakes 35 Magnitude and intensity of earthquakes 35 Influence of magnitude and surface geology on the characteristics of earthquakes 35 Representation of ground motion 37 Construction and representation of response spectra 39 Power spectral density functions for earthquakes 42 Soil-structure interaction 43 References 44 4 Generation of wind and earthquake histories 45 Introduction 45 Generation of single wind histories by a Fourier series 45 Generation of wind histories by the autoregressive method 46 Generation of spatially correlated wind histories 50 Numerical illustration 52 Generation of earthquake histories 52 Cross-correlation of earthquake histories 58 Design earthquakes 59 References 61 5 Freely hanging cables 63 Introduction 63 The governing equation for freely hanging cables 63 Cables with assumed distributed load wx along the span 65 Uniformly distributed load 65 Uniformly tapering distributed load 68 Two symmetrically placed triangularly distributed loads 70 References 71 6 Static analysis of cable structures 72 Introduction 72 Structures subjected to point loads only 75 The total potential energy at x in displacement space 75 The gradient vector of the total potential energy at x in displacement space 78 The method of steepest descent 79 The method of conjugate gradients 80 The Newton-Raphson method 80 The total potential energy at Xk+J in displacement space 82 Determination of S from the steplength polynomial 83 Member forces and displacements at Xk+J in displacement space 84 Laterally loaded cable elements 84 Slackening cable elements 85 Cable rupture 85 Cable elements with nonlinear stress-strain relationships 85 Buckling of strut elements 87 Change of temperature 87 Numerical ill-conditioning and scaling 87 Convergency criteria 88 Summary of the iterative procedures 88 Numerical example 89 First iteration 91 Second iteration 94 References 97 7 Dynamic analysis of weakly nonlinear cable roof structures: frequency domain analysis 99 The importance and extent of dynamic analysis 99 Aeroelasticity and dynamic response 99 Dynamic response analysis of aeroelastically stable cable roofs 100 Dynamic response of one-DOF systems to turbulent wind101 Relationships of response, drag force and wind velocity spectra for one-DOF systems 102 Dynamic response of multi-DOF structures to turbulent wind 106 Summary of expressions used in the frequency domain method for multi-DOF systems 109 Modal force spectra for wind for three-DOF systems 109 Aerodynamic damping of multi-DOF systems 110 Dynamic wind response analysis of weakly damped structures 112 Dynamic response of cable structures to earthquakes studied using frequency domain analysis 113 Dynamic response of one-DOF systems to earthquakes studied using power spectra 113 Influence of the dominant frequency of the ground on the magnitude of structural response 114 Dynamic response of multi-DOF structures to earthquakes studied using power spectra 115 Conclusion 116 References 117 8 Dynamic analysis of nonlinear cable structures: time domain analysis 118 Basic concepts 118 The force components of dynamic time-dependent loads 119 Force components due to wind 119 Force components due to support movements such as those caused by earthquakes and explosions 120 Force components due to other forms of dynamic loading 120 Dynamic analysis in the time domain 120 Assumptions 121 Total potential work at time (T + AT) 122 Total potential energy 124 Total potential structural energy dissipation 125 Total potential work of inertia forces 126 Total potential work of wind 127 Total potential work of inertia forces due to support movements 128 Total potential work of independent dynamic forces 129 Convergency and scaling 129 Stability and accuracy 130 Numerical illustration 130 References 136 9 Damping ratios and damping matrices 138 Introduction 138 Measurement and evaluation of damping and damping ratios138 The influence of air at resonance 139 Damping matrices 142 Modelling of structural damping by orthogonal damping matrices 142 First method 142 Second method 143 References 145 10 Cables and terminals 146 Wire strand rope 146 Steel 148 Manufacture of cables 148 Environmental factors affecting steel cables 150 Moisture 151 Water in mass (sea, river, lake or pond water) 151 Water as discrete droplets (rain or driven spray) 151 Water vapour 151 Heat and cold 152 Solar radiation 152 Solid particles 152 Protective coatings 153 Cable properties 153 Cable terminations 154 Linearization of cables-prestressing 157 Creep 160 Fatigue 161 Flexibility of cables 162 References 163 11 Tension anchors 164 Introduction 164 Types and suitability of tension anchors 165 Gravity anchors 167 Plate, mushroom and other anchors 167 Theory 167 Strip anchors 168 Circular anchors 169 Rectangular anchors 170 Group action 170 Pull-out tests in sand 171 Pull-out tests in clay 171 Long-term uplift capacity 171 Factor of safety 172 Tension piles 172 Tension piles in granular material 172 Tension piles in clay 173 Factor of safety 174 Ground anchors 175 Sand and gra vel 175 Medium-to-fine sand (k < 103 mjs) 176 Clay 177 Soft rock 177 Other points 178 Caution 178 Rock anchors 178 Mechanical anchors 178 Bonded anchors \ 78 Rock sockets 180 Design considerations 180 Concluding remarks 180 References 181 12 Cable beams and cable grids 182 Introduction 182 Structural characteristics 182 Preliminary design analysis of cable beams and grids188 Design and construction 195 Cladding and cladding materials 214 Erection of cable beams 221 Influence of boundary geometry on the forces at the boundary 221 Preliminary design-example 224 References 230 13 Cable net roofs 231 Introduction 231 Shape finding 231 Static and dynamic characteristics 239 Loading 261 Preliminary design analysis 261 Static and dynamic modelling of cable net structures 261 Design details 268 Methods of erection 272 Cladding and cladding materials 273 References 274 14 Design considerations 276 Introduction 276 Architectural requirements 276 Site location and geological information 277 Shape finding 277 Roof cladding and cladding materials 278 Wind and snow loading 278 Computer analysis and the use of models 279 Corrosion protection 280 Fire rating 280 Choice of contractor 281 Design and construction costs 281 Conclusion 282 15 Index 283
0727726242
624.1774 / BUC
Introduction to cable roof structures - Ed.2 - London Thomas Telford 1999 - xiv,285p.
CONTENTS Preface to the second edition xi Preface to the first edition xiii 1 Structural systems 1 Introduction 1 Simply suspended cable structures 2 Pretensioned cable beam structures 4 Pretensioned cable net structures 7 Pretensioned cable grid structures 8 General structural characteristics 11 Bibliography 13 2 The nature and statistical properties of wind 14 Introduction 14 The nature of wind 15 Mean wind speed and variation of mean velocity with height 17 Statistical properties of the fluctuating velocity component of wind 19 Variance and standard deviation 20 Auto-correlation and auto-covariance functions 21 Spectral density functions of longitudinal velocity fluctuations 21 Cross-correlation and cross-covariance functions 24 Cross-spectral density and coherence functions for longitudinal velocity fluctuations 25 The probability density function and peak factor for the fluctuating component of wind26 The cumulative distribution function 28 Pressure, drag and lift forces 28 References 32 3 The nature and statistical properties of earthquakes 33 Introduction 33 Types and propagation of seismic waves 33 Recording of earthquakes 35 Magnitude and intensity of earthquakes 35 Influence of magnitude and surface geology on the characteristics of earthquakes 35 Representation of ground motion 37 Construction and representation of response spectra 39 Power spectral density functions for earthquakes 42 Soil-structure interaction 43 References 44 4 Generation of wind and earthquake histories 45 Introduction 45 Generation of single wind histories by a Fourier series 45 Generation of wind histories by the autoregressive method 46 Generation of spatially correlated wind histories 50 Numerical illustration 52 Generation of earthquake histories 52 Cross-correlation of earthquake histories 58 Design earthquakes 59 References 61 5 Freely hanging cables 63 Introduction 63 The governing equation for freely hanging cables 63 Cables with assumed distributed load wx along the span 65 Uniformly distributed load 65 Uniformly tapering distributed load 68 Two symmetrically placed triangularly distributed loads 70 References 71 6 Static analysis of cable structures 72 Introduction 72 Structures subjected to point loads only 75 The total potential energy at x in displacement space 75 The gradient vector of the total potential energy at x in displacement space 78 The method of steepest descent 79 The method of conjugate gradients 80 The Newton-Raphson method 80 The total potential energy at Xk+J in displacement space 82 Determination of S from the steplength polynomial 83 Member forces and displacements at Xk+J in displacement space 84 Laterally loaded cable elements 84 Slackening cable elements 85 Cable rupture 85 Cable elements with nonlinear stress-strain relationships 85 Buckling of strut elements 87 Change of temperature 87 Numerical ill-conditioning and scaling 87 Convergency criteria 88 Summary of the iterative procedures 88 Numerical example 89 First iteration 91 Second iteration 94 References 97 7 Dynamic analysis of weakly nonlinear cable roof structures: frequency domain analysis 99 The importance and extent of dynamic analysis 99 Aeroelasticity and dynamic response 99 Dynamic response analysis of aeroelastically stable cable roofs 100 Dynamic response of one-DOF systems to turbulent wind101 Relationships of response, drag force and wind velocity spectra for one-DOF systems 102 Dynamic response of multi-DOF structures to turbulent wind 106 Summary of expressions used in the frequency domain method for multi-DOF systems 109 Modal force spectra for wind for three-DOF systems 109 Aerodynamic damping of multi-DOF systems 110 Dynamic wind response analysis of weakly damped structures 112 Dynamic response of cable structures to earthquakes studied using frequency domain analysis 113 Dynamic response of one-DOF systems to earthquakes studied using power spectra 113 Influence of the dominant frequency of the ground on the magnitude of structural response 114 Dynamic response of multi-DOF structures to earthquakes studied using power spectra 115 Conclusion 116 References 117 8 Dynamic analysis of nonlinear cable structures: time domain analysis 118 Basic concepts 118 The force components of dynamic time-dependent loads 119 Force components due to wind 119 Force components due to support movements such as those caused by earthquakes and explosions 120 Force components due to other forms of dynamic loading 120 Dynamic analysis in the time domain 120 Assumptions 121 Total potential work at time (T + AT) 122 Total potential energy 124 Total potential structural energy dissipation 125 Total potential work of inertia forces 126 Total potential work of wind 127 Total potential work of inertia forces due to support movements 128 Total potential work of independent dynamic forces 129 Convergency and scaling 129 Stability and accuracy 130 Numerical illustration 130 References 136 9 Damping ratios and damping matrices 138 Introduction 138 Measurement and evaluation of damping and damping ratios138 The influence of air at resonance 139 Damping matrices 142 Modelling of structural damping by orthogonal damping matrices 142 First method 142 Second method 143 References 145 10 Cables and terminals 146 Wire strand rope 146 Steel 148 Manufacture of cables 148 Environmental factors affecting steel cables 150 Moisture 151 Water in mass (sea, river, lake or pond water) 151 Water as discrete droplets (rain or driven spray) 151 Water vapour 151 Heat and cold 152 Solar radiation 152 Solid particles 152 Protective coatings 153 Cable properties 153 Cable terminations 154 Linearization of cables-prestressing 157 Creep 160 Fatigue 161 Flexibility of cables 162 References 163 11 Tension anchors 164 Introduction 164 Types and suitability of tension anchors 165 Gravity anchors 167 Plate, mushroom and other anchors 167 Theory 167 Strip anchors 168 Circular anchors 169 Rectangular anchors 170 Group action 170 Pull-out tests in sand 171 Pull-out tests in clay 171 Long-term uplift capacity 171 Factor of safety 172 Tension piles 172 Tension piles in granular material 172 Tension piles in clay 173 Factor of safety 174 Ground anchors 175 Sand and gra vel 175 Medium-to-fine sand (k < 103 mjs) 176 Clay 177 Soft rock 177 Other points 178 Caution 178 Rock anchors 178 Mechanical anchors 178 Bonded anchors \ 78 Rock sockets 180 Design considerations 180 Concluding remarks 180 References 181 12 Cable beams and cable grids 182 Introduction 182 Structural characteristics 182 Preliminary design analysis of cable beams and grids188 Design and construction 195 Cladding and cladding materials 214 Erection of cable beams 221 Influence of boundary geometry on the forces at the boundary 221 Preliminary design-example 224 References 230 13 Cable net roofs 231 Introduction 231 Shape finding 231 Static and dynamic characteristics 239 Loading 261 Preliminary design analysis 261 Static and dynamic modelling of cable net structures 261 Design details 268 Methods of erection 272 Cladding and cladding materials 273 References 274 14 Design considerations 276 Introduction 276 Architectural requirements 276 Site location and geological information 277 Shape finding 277 Roof cladding and cladding materials 278 Wind and snow loading 278 Computer analysis and the use of models 279 Corrosion protection 280 Fire rating 280 Choice of contractor 281 Design and construction costs 281 Conclusion 282 15 Index 283
0727726242
624.1774 / BUC