Synopsis.
From a review of existing knowledge of wind loads it is clear that, although many observations of wind velocities and pressures have been made, it is difficult to estimate their true significance with reference to the derivation of design loads. Velocities vary considerably over the wind front and fluctuate rapidly, and the pressures actually recorded may act on only a small area of a structure and for only a few seconds. Hitherto, practically no attention has been given to the time effect, and an attempt is made in this Paper to estimate the probable damage inflicted on a structure during a high wind. The damage is expressed in terms of the permanent plastic deformation and, hence, wind loads suitable for use in ultimate (plastic) design methods may be derived. Although some numerical results are given, it is found that available data on wind velocities and pressures are insufficient to enable full calculations to be made. The investigation shows clearly the nature of further research which should be under-taken in order to achieve a rational treatment of wind loading.
