Characteristics of internal pressures and net local roof wind forces on a building exposed to a tornado-like vortex

Extreme disturbances in the atmosphere such as tornadoes produce large wind loads on buildings that sometimes result in structural failures. Post-tornado investigations have revealed that building roofs are vital components that often suffer extensive damage. An experimental investigation using the tornado-like flow simulator at Tokyo Polytechnic University was performed to obtain a better understanding of the effects of building location with respect to vortex, for two opening types, on the internal pressures in a building and consequent changes in net local roof wind force. Such studies are significant from the viewpoint of design of components and cladding elements. The lowest minimum peak values of net local roof wind force experienced by a building with 0.1% opening ratio, for building models located well within the vortex core, were 1.4 times the values for a building model with 3.9% opening ratio.

► Experimental investigation of internal pressures and net roof force using tornado simulator.
► Minimum peak internal pressure coefficients differed by 1.2 times for different openings.
► Lowest minimum peak values of net roof force showed a difference of 1.4 times.