提出了估算开孔结构风致内压脉动的频域分析方法,并实施了风洞试验进行验证。针对结构迎风面开孔的不利状况,根据伯努利方程导出内压响应动力微分方程,再采用能量法将非线性阻尼线性化,结合随机振动理论及迭代算法得到风致内压脉动量,通过数值算例分析了开孔结构内压频响特性及开孔率、开孔数量与开孔位置对风致内压脉动的影响。设计制作了迎风墙面具有不同开孔的刚性模型对结构内部进行风洞测压试验,试验结果与理论结果较为吻合。理论与试验研究结果均表明,对于结构单一开孔,空腔-孔口动力系统的频响特性及孔口外压谱决定了内压的脉动量,而多处开孔时各孔口风压的相关性也成为影响内压脉动的重要因素。
A method for estimating wind-induced fluctuating internal pressure in the frequency domain is proposed and wind tunnel tests were carried out to verify the method. Based on Bernoulli equation, nonlinear differential equation for dynamic internal pressure is derived and random vibration theory combined with iteration algorithm is used to obtain the solution. Numerical examples are provided to investigate frequency response characteristic of internal pressure and the influences of opening ratio, opening number and opening position on fluctuating internal pressure. A series of low-rise building models with various openings were designed and wind tunnel tests were conducted. Experimental results agree well with theoretical ones. It is shown that the internal pressure fluctuation is determined by the frequency response characteristic of the cavity-orifice dynamic system and orifice pressure spectrum for single opening structures. For structures with multiple openings, wind pressure correlations at orifices also affect fluctuating internal pressure considerably.