Modern, light-weight, slender structures are liable to oscillations caused by wind; suspension bridges, towers and chimney stacks are particularly prone. The main purpose of this Monograph is to provide information for engineering students as well as for the practising engineer, about the problem of wind-excited oscillations of structures, and to show how tests on models in a wind tunnel may be used to assess the response of the full-scale structure to natural winds. The more common aerodynamic mechanisms causing instability and the characteristic response associated with them are explained, and the various types of instability are exemplified using the results of some model investigations.

Measurements of the velocity profiles and turbulence of the natural wind, and their representation in a wind tunnel, are developing fields of investigation. The present approach towards a description of the structure of strong winds is outlined in the Appendix; techniques for wind-tunnel modelling of the natural wind are discussed in the main text.

Although it is assumed in this booklet that the reader has some knowledge of the use of non-dimensional parameters for scaling purposes. sufficient practical detail is given to enable a reader without such knowledge to understand how full-scale values are obtained from model-scale results.