풍동실험 대상여부 판단 근거자료

 

2023. 10. 26

풍력실험 기법에서의 큰 그림

Two popular techniques are available for implementing aerodynamic models. One is the widely used force balance technique capable of measuring the overturning moment on a rigid and lightweight (typically styrofoam or balsa) model mounted on a high-fidelity force balance transducer system. The other is the synchronous pressure integration technique capable of measuring synthesizing pressures from many (typically hundreds) pressure taps installed in a pressure (plastic) model. The aerodynamic model techniques are widely used to predict dynamic wind loads on tall buildings under strong wind events. Although either of the two techniques may be better fit for different tall structures, the basic principle inherent of the aerodynamic model is identical. The overall procedure based on the aerodynamic moment response approach as shown in figures is briefly summarized as following. (1) wind excitations that the prototype structure is expected to undergo are properly simulated in an atmospheric boundary layer wind tunnel. (2) aerodynamic moments impinged on the geometrical analogue of the prototype structure, which are characterized by its architectural and structural mode shapes, are acquired from either the base overturning moments sensed by a force balance model or synchronously measured surface pressures at various levels of the pressure model, and then they are to be interpreted as the modal loads in a simplified and dynamically equivalent single-degree-of-freedom system. (3) a mechanical transfer function triggered by the prototype’s structural characteristics is incorporated into the formulation of aerodynamic moment responses. The aerodynamic moment response spectra determined in frequency domain are to be applied to evaluate quasi-static and resonant contributions to the prototype response to wind excitations. (4) the equivalent static wind loads and dynamic wind responses are readily estimated using the aerodynamic moment responses and influence coefficients featured by floor mass and mode shape information on the prototype structure.

2021. 08. 27