基于STD法的光岳楼木结构自振频率计算

Natural Frequency Calculation of Guangyue Tower Based on the Method of STD

自振频率是古建筑木结构振动特性的重要模态参数指标,准确计算其自振频率对采用数值方法分析结构的动力反应及对结构进行安全评估至关重要.本文基于实测振动数据,采用STD方法计算得到了光岳楼木结构的自振频率,并与东华振动测试系统的模态分析软件中OP.Polylscf算法计算得到的光岳楼木结构的自振频率进行了对比分析.表明:采用上述两种方法计算得到的反映木结构振动特性的1阶频率差别甚小;采用OP.Polylscf法计算光岳楼木结构的其他各阶频率均大于采用STD法计算结果,但误差均在5.7%以内,说明采用STD法计算木结构的自振频率具有较好的精度.

Natural frequency of historic timber structure is an important modal parameters of its vi- bration characteristics. The accuratly calculation of structure natural frequency is very important for an- alysing structural dynamic response based on numerical method and assessing safety of the structure. This paper is based on the measured vibration data, it used STD method to calculate the natural frequen- cy of guangyue tower, and make comparison with the one which used donghua vibration modal analysis of the testing system software according to OP. Polylscf method. The results shown that the difference of the above two methods which means to calculate 1 order natural frequency of timber structure is very small; The result of using OP. Polylscf method to calculate other frequencies except 1 order is greater than the results of taking STD method. However, the error of two results is within 5.7%, which indi- cates that compared to calculate the natural frequencies of the timber structure, the STD method has good precision.