Acting Effects of Roof Pitch of a Gabled Structure on Unsteady Wind Force under a Step-function-like Gusty Wind

Abstract

It is known a wind force acting on a structure under a gust with a very short rise time occasionally reaches a large value not seen in a steady wind flow. In this paper, the properties of unsteady wind force on bodies with gable roofs of two different pitches were investigated using a tunnel test. It was found that the overshoot coefficient decreased with an increase in non-dimensional rise time. The rate at which the overshoot coefficient reduced was different depending on a roof pitch of body. The overshoot phenomenon of the lift acting on a 1/4-pitched roof body occurred in bigger non-dimensional rise time than a 1/2-pitched one.