Hysteretic And Dynamic Behavior Simulation Analysis Of Seventh-Class Wood Frame

Chinese ancient building timber structure has experienced several earthquakes and accumulated damage erosion in the long history of the world,and still stands.It represents the culture and wisdom of the Chinese nation and plays an irreplaceable role in cultural heritage.Studying the energy dissipation mechanism and seismic characteristics of ancient wooden structures can not only protect ancient buildings better,but also provide a good reference for modern structures.In this paper,according to the relevant dimensions stipulated in the Constructive Formula^[1],a three-level weightless and a wooden frame model with bucket-tree and bucket-tree with bucket-tree are established for the seventh grade timber with typical characteristics of Chinese ancient timber structures.?1?The pseudo-static test simulation of the bucket-free tamarind-tree frame model is carried out.Deformation characteristics,hysteresis curve,skeleton curve,stiffness degradation curve and energy conversion during reciprocating loading are obtained.The analysis shows that the initial stiffness of wood frame is larger.With the loading,the stiffness gradually degrades,and the larger the vertical weight,the faster the degradation rate.There are three main ways of energy conversion:hysteretic energy dissipation,mass lifting and structural elastic deformation.Quantitative data analysis shows that the energy proportion of three conversion modes in the process of reciprocating loading changes.The energy proportion of mass block lifting and structural elastic deformation conversion is larger in the initial stage of loading,and the energy consumption of hysteresis and mass block lifting in the later stage are larger.The mass block lifting is the main way of structural energy conversion in the whole loading process.?2?Simple harmonics of different frequencies and magnitudes are applied to the model of bucket-free and bucket-laden timber frames.Then three seismic waves with characteristic periods approaching their natural periods,El Centro wave,Taft wave and Tianjin wave,are selected for time-history analysis.The relative displacement time-history curve of the top and bottom of the column and the peak acceleration of the key points are extracted,and the dynamic characteristics of the two kinds of wood frames are analyzed.The results show that the natural vibration period of the bucket structure is slightly larger than that of the non bucket timber frame;the larger the vertical counterweight and the higher the seismic wave intensity,the better the isolation effect of the wooden frame;the smaller the interlayer displacement angle of the two kinds of wooden frames,the better the energy dissipation capacity of the wooden frame,the better the isolation effect and the stronger energy dissipation capability of the bucket frame structure.