Testing of Metal Roofing Systems under Simulated Realistic Wind Loads

摘要

A new technique for testing roof panels has been devised that simulates true wind pressure loads more accurately than conventional "pressure-box" tests. The basis of the simulation is the application of uplift loads through high-power custom-built electromagnets. The electromagnets are controlled such that they apply suction loads that closely follow "true" uplift loads derived from wind tunnel tests over corresponding tributary areas, including their temporal and spatial variations. These wind tunnel loads were measured and scaled to simulate corner panel load time histories that would have occurred in Hurricane Andrew. The UWO input loads and the construction of the MSU electromagnets to apply the loads in time and space are detailed, together with response measurements and comparisons with the uniform pressure response for a standing seam metal roof. The results clearly show that suction forces induced by electromagnets can be used successfully to duplicate the unsteady non-uniform uplift loading of wind tunnel data in time and space. Furthermore, the load transfer from the standing seam metal roofing to the anchoring clips along the supporting purlins was successfully recorded through measuring clip loads for the full duration of the static and simulated uplift wind loading.