Wind Forces in Engineering

Preface to the Second Edition

Chapter 1 Introduction

1.1. Past and Present

1.2. Basic Considerations

1.3. History

1.4. Thesis

1.5. Principal Sources of Information

1.6. Terminology

Chapter 2 Wind Data

2.1. Air Movement

2.2. Wind Measurement

2.3. Wind-speed Measurements

2.3.1. Wind-speed Estimation

2.3.2. Short-term Measurements

2.3.3. Anemographs

2.3.4. Gust records

2.4. Wind Data Obtained

2.4.1. Non-continuous Records

2.4.2. Continuous Records

2.4.3. Short-term Records

2.4.4. Extreme Data

2.4.5. Gust Factor�winds of Various Mean Periods

2.5. Maxima for Non-recorded Sites

2.6. Tropical Storms and Tornadoes

2.6.1. Tropical Storms

2.6.2. Mixed Storm Conditions

2.6.3. Tornadoes

2.7. Wind-speed Variation with Height

2.8. Miscellaneous Effects

2.9. Design Requirements

Chapter 3 Basic Shape Factors

3.1. Shape Factors

3.1.1. Separation

3.1.2. Model Laws

3.1.3. Force and Moment System

3.2. Pressure Distributions

3.2.1. Flat Plates

3.2.2. Rectangular Blocks

3.2.3. Spheres and Cylinders

3.3. Forces on Basic Shapes

3.3.1. Aspect Ratio

3.3.2. Drag factors

3.3.3. Interference Effects

3.3.4. Roughness Effects

3.4. Trusses

3.4.1. Masts and Towers

3.4.2. Other Factors

3.5.Meshes

3.6. Moments

3.6.1. Area Moments

3.6.2. Pressure Moments

3.6.3. Aerodynamic Moments

3.6.4. Moments on a Rotating Structure

3.7. Other Force and Moment Data

Chapter 4 Wind-tunnel Techniques

4.1. Wind-tunnels

4.1.1. Closed-jet Tunnels

4.1.2. Open-jet Tunnels

4.1.3. Wind-tunnel Fittings

4.1.4. Wind-flow Patterns

4.2. Models

4.2.1. Model Mountings

4.2.2 Model Laws

4.3. Wind-tunnel Conventions

4.4. Measurement Corrections

4.4.1. General

4.4.2. Model Interference on the Measurement of Air Velocity

4.4.3. Wall Constraint Corrections

4.4.4. Blockage Corrections in Closed Wind-tunnel

4.4.5. Blockage Corrections for Open-jet Tunnels

4.5. Wind-tunnel Measurements and Calculations

4.5.1. Rigid Models�forces and Moments

4.5.2. Rigid Models�pressure Tests

4.5.3. Rotating Models�moments

4.5.4. Rigid Models�oscillatory Tests

4.5.5. Flexible (aeroelastic) Models

4.6. Random Turbulence and Excitation

Chapter 5 Dynamic Effects

5.1. Basic Considerations

5.2. Rigid Structures�Single-frequency Excitation

5.3. Single-frequency Excitations

5.3.1. Vortex Oscillations

5.3.2. Suppression of Vortex Excitation

5.3.3. Experimental Analysis

5.3.4. Galloping Oscillations

5.4. Flutter

5.5. Rigid Structures�Random Excitation

5.5.1. Maximum Response Amplitude

5.5.2. Analysis of Random Excitation

5.5.3. Randomly Fluctuating Eddy Effects

5.6. Flexible Structures (multi-degree-offreedom Systems)

5.6.1. Lagrange's Equation

5.6.2. Deflections, Stresses and Bending Moments

5.6.3. Discrete Vortex Excitation of a Flexible Structure

5.6.4. Random Vortex Excitation of a Flexible Structure

5.6.5. Random Gust Excitation of a Flexible Structure

5.7. Fatigue Loading

Chapter 6 Bridges

6.1. Static Forces

6.1.1. Plate-girder Construction

6.1.2. Truss Construction

6.2. Dynamic Forces

6.2.1. Structural Characteristics

6.2.2. Damping

6.3. Excitation

6.3.1. Complete Model Tests

6.3.2. Complete Model Test: Truss Bridge

6.3.3. Section Model Tests

6.3.4. Summary of Aerodynamic Instabilities

6.3.5. Erection Instabilities

6.4. Buffeting

Chapter 7 Buildings

7.1. Static Wind Effects

7.1.1. Tall Buildings

7.1.2. Long Low Buildings

7.1.3. Houses

7.1.4. Roofs

7.1.5.Cladding

7.1.6. Chimneys

7.1.7. Full-scale Effects

7.2. Dynamic Effects on Buildings

7.3. Design Procedure for Wind Forces on Buildings

7.4. Air-flow around Buildings

Chapter 8 Masts and Towers

8.1. Shape Factors

8.2. Mast and Tower Movement due to Gust Excitations

8.3. Non-gusting Excitation of Masts and Towers

8.3.1. Modal Shapes and Frequencies

8.3.2. Damping

8.3.3. Vortex Excitation

8.3.4. Full-scale Vortex Excitation

8.4. Miscellaneous Excitations

Chapter 9 Special Structures

9.1. Cables

9.1.1. Static Forces on Cables

9.1.2. Ice Formation on Cables

9.1.3.Oscillating Forces on Cables

9.1.4. Gust Excitation of Cables

9.1.5. Vortex Excitation of Cables

9.1.6. Galloping Excitation of Cables

9.1.7. Oscillations of Twin Conductors

9.2. Cooling Towers

9.3. Radar and Communications Aerials

9.3.1. Forces and Moments on Static Aerials

9.3.2. Lattice Aerials

9.3.3. Solid-surface Aerials

9.3.4. Gust Effects

9.3.5. Rotating Aerials

9.4. Radomes

Chapter 10 Codes of Practice

10.1. Wind-speed Regions

10.2. Topographical Factors

10.3. Wind Variation with Height

10.4. Ice and Snow Loads

10.5. Gust Effects

10.6. Shape Factors

10.7. Pressure Coefficients

10.8. Shielding Effects

10.9. Buildings, Roofs and Cladding

10.10. Cross-wind Effects

10.11. Chimneys, Tanks, etc.

10.12. Towers, Masts and Trusses

10.13. Tables from Reference 136

Appendixes

Appendix 1. Notation Used in Chapters 1-9

Appendix 2. Standard Aerodynamic and Conversion Data

Appendix 3. Characteristics of Wind-measuring Instruments

Appendix 4. Shelter Effects

References

Index