Effect of opening size and wind speed on internal pressures in full-scale buildings

Internal pressures contribute to a significant proportion of the net pressure across a building envelope, which needs to be accurately defined in wind loading standards to optimize structural design. Current quasi-steady criteria for internal pressures in AS/NZS1170.2(2011) is dependent on the ratio of open area on the windward wall to leeward and sidewalls, with no consideration of dynamic (i.e. inertial and damping) effects. This paper shows that the internal to external pressure fluctuation relationship is a function of the opening area to volume parameter, S*=(A^(3/2)/V)(as /U_h^2) and opening area to integral length scale of turbulence parameter, Φ5=(λu /√A). Simple quasi-steady analysis used in AS/NZS1170.2(2011) suggests internal pressure should be equal to the external pressure applied to the opening, however, results here show Cases where peak internal pressures are greater than, equal to and less than the peak external pressure. This is caused by internal pressure resonance and/or damping shown to be a function of S* and Φ_5