屋盖角部开孔的低矮房屋屋面风荷载特性研究

基于实测房屋模型风洞试验,分析了屋盖角部不同开孔大小和开孔形状情况下低矮房屋的风荷载特性.内外压的叠加作用使屋盖上出现了很大的正风压,内压整体分布均匀,开孔面积越小,内压作用越强;内压的概率密度接近于高斯分布,净压的非高斯特性相比于外压有所减弱;内压在频域内也表现出很强的相关性,内压谱在Helmholtz频率和漩涡脱落频率处均出现了谱峰值,净压谱中漩涡脱落作用被抵消;内压的荷载特性间接反映出迎风前缘的长度有利于锥形涡的发展,成对出现的锥形涡并非同时同步达到最强.

Study of the Wind-induced Roof Pressure Characteristics of a Low-rise Building with Holes on Its Roof Corner

Based on the wind tunnel testing of a low-rise building, the wind pressure characteristics of the low-rise building with holes of different sizes and shapes on its roof corner were analyzed. The superimposition of internal and external pressures makes the emergence of large positive pressure on the roof. The internal pressure shows an overall uniform distribution. With the opening area becoming smaller, the internal pressure gets stronger. The probability density function of the internal pressure is closer to the Gaussian distribution, and when compared with external pressure, the non-Gaussian characteristic of net pressure is weakened. The internal pressure also exhibits a strong correlation in frequency domain. There appear two humps in the internal pressure spectrum corresponding to Helmholtz frequency and vortex shedding frequency, and the peak of the vortex shedding frequency is offset for the case of net pressure. Furthermore, the internal pressure characteristics indirectly show that the length of the front edge enhances the development of the conical vortices and the conical vortices appearing in pairs do not become the strongest simultaneously.