| With the rapid development of economic society and scientific technology,the architectural structure needs not only to meet its specific architectural functions,but also to have a certain image of architectural art.A large number of wind sensitive buildings with the characteristic of light weight,large span and flexible stiffness have emerged,and the frequency of special shape,irregular facade and opening has also increased significantly.Compared with the ideal totally enclosed building,the response of the building considering the combined action of internal and external pressure is more complex,and the stress situation is more unfavorable.Therefore,in order to ensure the safety and reliability of the wind resistant design of the structure,the internal pressure induced by wind must be a part that can not be ignored.Due to the need to satisfy the similarity theorem of internal pressure,it is difficult to measure the windinduced internal pressure of multi space structures by wind tunnel test,but only by calculation.At present,the internal pressure calculation is only for the limited single space or two space buildings.There are many space in the large-scale buildings in the project,so the existing internal pressure calculation method is difficult to expand to more space.In this paper,a more in-depth and effective research on this problem is carried out,and a feasible solution is proposed,and relevant comparative analysis and experimental comparison are carried out.The main work and conclusions are as follows:(1)Based on the equivalent linearization of the basic government equation of internal pressure,the simple relationship between flow and pressure in the pressure transfer unit is derived by using the idea of node gridding.Based on this,the amplitude frequency relationship between internal pressure and external pressure in any multi separated space is established,so as to obtain the variance value of fluctuating internal pressure and the correlation coefficient between different internal pressure,internal pressure and external pressure.The calculation method can consider the background leakage,multiple openings,multiple spaces and other architectural features at the same time,which increases the applicability of the basic government equation of internal pressure and the operability of internal pressure calculation,and has high calculation efficiency.(2)The natural frequency of the internal pressure system is identified by frequency sweep method,and the internal pressure response gain function is obtained.The effects of internal spaces,internal volumes,opening characteristics,background leakage and inertia coefficient on the dynamic response characteristics of the internal pressure system are compared.The results show that the order of natural frequency of multi space system depends on the number of space,and the increase of opening area will lead to the increase of natural frequency of the system;the space closest to the outer opening at the first frequency will get the minimum internal pressure gain,while the space furthest from the outer opening will get the maximum internal pressure gain.(3)Based on the simplified model of a practical engineering case,the internal pressure response is analyzed and evaluated by using the calculation method and taking external pressure data of the wind tunnel as the input.Then this paper changes the wind angle of the structure,the size and lo00 cation of the opening,the internal partition,calculates the fluctuating energy of the internal pressure,analyzes the correlation between the internal and external pressure of the roof,and compares the impact of the net pressure fluctuation only considering the external pressure fluctuation and the combined effect of the internal and external pressure on the roof.It is found that the Helmholtz resonance effect is more obvious in the leeward region,and the net pressure fluctuation of the roof will be larger due to the combined effect of the internal pressure fluctuation in the leeward region. |
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