泄洪低频声波诱发房屋卷帘门振动分析研究

伴随大坝泄洪产生的低频声波(10 Hz以下气压脉动),在一定范围内会诱发房屋门窗振动、造成人体不适等。为了评估泄洪低频声波产生的环境危害,在开展泄洪低频声波原型观测的基础上,利用有限元软件建立房屋卷帘门结构系统模型。首先对卷帘门进行模态分析,计算各阶固有频率和振型;接着分别对卷帘门在不同开度及不同边界条件下进行模态分析,模拟开度和边界约束对卷帘门自振特性的影响;然后对系统进行不同约束条件下的瞬态分析,模拟卷帘门的振动响应,并根据模拟结果改进边界条件,从而减小卷帘门的晃动,改善系统的动态特性。最后模拟了房屋结构振动引起的卷帘门振动响应,其振动量级远小于低频声波直接作用造成的振动。

Analysis and research of the shutter doors vibration induced by low frequency noise of flood discharge

Low frequency noise(lower than 10Hz of air pulsation),accompanied by flood discharge of large dam, may cause the vibration of house doors and windows and the discomfort of residents to some extent. In order to assess the environmental hazards of low-frequency noise induced by flood discharge, this arti-cle,based on the prototype observation of low frequency noise,illustrates a shutter doors system model es-tablished by using ANSYS. Modal analysis was carried out firstly on the shutters to calculate each order nat-ural frequency and vibration mode;then carried on modal analysis of shutter doors at different opening and under different boundary conditions, to simulate the effects that opening and boundary constraints have on self-vibration characteristics;then transient analysis of the system was accomplished under different con-straint conditions to simulate the vibration response of the shutter doors, and improve boundary conditions according to the simulation result, so as to reduce the shutter doors shaking, thus improving the dynamic characteristics of the system;in the end, simulate the shutters vibration caused by the structure of house vibration,and the vibration magnitude is much smaller than that caused directly by low frequency noise.