Seismic Performance Of Fourth-Class Ancient Wood Frame

China’s long history has created splendid Chinese civilization,and wood structure is an important part of it.These wood structures are not only an important part of China’s cultural heritage,but also an important part of the world cultural heritage after years of vicissitudes.Since ancient times,earthquakes occur frequently in China.It is of great help to study the seismic performance of wood structure for the repair of ancient buildings.In this paper,according to the relevant regulations of wood classification and column top counterweight in the Song Dynasty’s Constructive Formula and Wang Tian’s preliminary study on the static force of ancient big wood,the Abaqus finite element analysis software is used to establish the four grade wood frame model,and the model is loaded horizontally.The low cycle reciprocating loading tests of wood frame with different vertical weights are carried out,and the deformation characteristics,hysteretic curve,skeleton curve,stiffness degradation curve and energy conversion in the process of reciprocating loading are obtained.The results show that shear and sliding deformation occur in the loading of wood frame,and the larger the vertical weight is,the higher the initial stiffness is.The rigidity of the straight tenon is larger than that of the dovetail wood frame,the rigidity attenuation is slow,the resilience of the straight tenon wood frame is larger than that of the dovetail wood frame,and the bearing capacity of the wood frame is stronger.The rigidity of the Dou Gong is large,and its hysteretic curve is narrow shuttle type.During the loading process,the horizontal displacement is small.During the whole loading process,the Dou Gong has been in the elastic development state.In the low cycle reciprocating test,there are three kinds of conversion forms of the total energy input into the wood structure,namely,elastic deformation energy,gravitational potential energy and hysteretic energy.For dovetail tenon,most of the energy input into the wooden frame is converted into gravitational potential energy,the rest is dissipated through hysteretic energy and elastic potential energy,most of the energy for the straight tenon is converted into elastic potential energy,the rest is converted into hysteretic energy and gravitational potential energy,and the hysteretic energy consumption of the straight wooden frame is far lower than that of the dovetail wooden frame.For dovetail wooden frame,the energy dissipation of wooden frame with Dou Gong is similar to that without Dou Gong,and the hysteretic energy consumption capacity of Dou Gong is weak,but due to the large number of components,the proportion of hysteretic energy consumption and elastic potential energy of the wooden frame with Dou Gong is slightly higher than that of the wooden frame without Dou Gong,and the proportion of gravitational potential energy is slightly lower.