Study On Dynamic Analysis Model Of Ancient Wood Structure Based On Traffic Excitation

The ancient building is an important part of Chinese traditional culture, it reflects the national brilliant history, and reflects the great achievements of the past Chinese culture art,science and technology. Chinese ancient architecture built long ago, after the wind, rain,snow erosion and earthquakes, war damage, resulting in ancient buildings exist in varying degrees of damage. At the same time, along with the increase of the traffic, the influence of the high-speed railway, highway, subway, light rail, the city traffic source vehicle etc. on ancient buildings can not be ignored. To determine the vibration caused by traffic vehicles(traffic excitation) index of wood structure safety of the ancient buildings under evaluation,and to predict the influence of existing and planned transportation along the traffic vibration on the surrounding of ancient buildings, the premise is the establishment of a reasonable structure dynamic analysis model.Based on the national key cultural relics protection units – Liaocheng Guangyue tower as an example, on the basis of experimental data, evaluate the traffic excitation affects on the Guangyue tower, analysis the mechanical property parameters which can reflect the actual situation of the ancient timber structure, modify the finite element based on the structure of initial state model in order to reflect the change of ancient wood structure stiffness more reasonably, and then calculate the stiffness parameters of dynamic analysis model which can reflect the actual situation of the ancient timber structure, which is the basis for the analysis of dynamic response of ancient buildings. The main research contents are as follows:(1) Analysis of traffic excitation on the Guangyue tower structural response“Technical specifications for protection of historic buildings against man-made vibration” to determine the control monitoring point speed response rules, half of the maximum peak to peak value of each measuring point velocity from the same height, the same direction as the process, and take an average of five times. According to the method,take a point to Guangyue roof layer for example, checking whether the control velocitymonitoring points meet the required level of “Technical specifications for protection of historic buildings against man-made vibration” permissible vibration velocity.(2) Identification of dynamic parametersUsing the DHMA analysis software of Donghua company, to process the measured vibration signal to smooth, eliminating the trend of processing, and to obtain the dynamic characteristics of Guangyue tower wooden structure, including the type of vibration,damping ratio, natural frequency of vibration modal parameter.(3) Determination of the Mortise and tenon connection stiffness of Guangyue tower wood structureAnalysis the Guangyue tower structure characteristics, dynamic characteristics, stress principle and other factors, according to the characteristics of Guangyue tower semi-rigid connections, select the reasonable unit types, using finite element analysis software ANSYS to establish three-dimensional finite element model, then carry out the modal analysis, to modify the original model according to the measured modal parameters.