结构的固有频率是研究结构动力性能的最基本参数.采用激振锤人工敲击法和有限元软件模态分析法计算出木结构古建筑结构模型的固有频率,并将二者所得结果进行比较;同时,根据振动台试验,提出了一种计算木结构古建筑固有频率的新方法一振动台试验法,给出了计算简图并提出了此方法在实际试验中可能会遇到的几个问题.通过研究表明:人工敲击法测得振动台试验模型震前的固有频率为2.05Hz,比地震最大加速度为100gal震后的固有频率(2.1Hz)略小;ansys有限元软件模态分析的结构一阶固有频率为2.226Hz,稍微高于激振锤人工敲击法测得结果;由于木结构古建筑构件之间的连续性和互相约束性能较差以及谱曲线放大以后,肉眼读取的数据结果存在一定的误差,可能会导致振动台试验法无法准确的计算出结构固有频率.为木结构古建筑的研究和修缮加固提供参考依据。
The nature frequency of the structure is the most basic parameter for the research on structural dynamic proper- ties. It mainly adopts method of hammering and modal analysis to calculate the nature frequency of ancient timber struc- ture, and makes comparison between them, Meanwhite, according to shaking table test, it puts forward a new method to calculate the nature frequency--method of shaking table test, gives its calculation model and puts forward a few questions the method may encounter in test. Research shows that the nature frequency got by the method of hammering is 2.05Hz, smaller than that got after earthquake with 100gal; and the nature frequency got by method of modal analysis is 2. 226Hz. Such result is a little larger than that got by method of hammering. It may be unable to accurately calculate the nature fre- quency because the continuity and mutual constraint performance between components are very poor and the error lying in data results from the naked eye. The conclusion and the views reached by this paper can provide a good reference to the research and repair reinforcement of the ancient timber structure.