Structural Performance Of Typical Mortise-tenon Joints Of Tingtang-style Timber Buildings Built During Song And Yuan Dynasties In South Yangtze River Regions

The building techniques of the ancient timber buildings especially those built during Song and Yuan dynasties in the South Yangtze river regions had influenced the development of the timber buildings in the north of China and the surrounding countries.At present,researches on the ancient timber buildings in the north of China is comprehensive,but researches on the structural performance of ancient timber buildings in the south of China,especially those timber buildings in the South Yangtze river region built during Song and Yuan dynasties,is insufficient.In order to protect these cultural relics scientifically,it is urgent to carry out the research on the structure performance of the ancient timber buildings built during Song and Yuan dynasties in the South Yangtze river region.Firstly,this paper presents the main structure characteristics of Tingtang-Style timber buildings in the South Yangtze river regions during Song and Yuan dynasties,including material properties,structural arrangement principles,structural compositions,timber frame features and summarizes structural features and functions of the main mortise-tenon joints.Then eight kinds of mortise-tenon joints have been designed according to the results of investigation and "yingzao fa shi",including 7 kinds of combined mortise-tenon joints and 1 Tou-sun mortise-tenon joint,and 8 specimens have been tested under low-cyclic reversed loading.Experimental study shows that the Tou-sun Ding-tou-gong mortise-tenon joints have good performance in ultimate bearing capacity,structural safety reserve,stiffness degradation and ductility.Although the Ban-sun and Tou-sun Ding-tou-gong mortise-tenon joint has good ultimate bearing capacity,the ductility of the joint is poor.The performances of the Shuang-mao Ding-tou-gong mortise-tenon joints and the Ban-sun Ding-tou-gong mortise-tenon joints are not as good as that of the Tou-sun Ding-tou-gong mortise-tenon joints,but still better than theTou-sun mortise-tenon joint.For comparison,the influence on the structural performance of the number of Ding Tou Gong is not as obvious as that of its mortise-tenon forms.Finally,the structural performances of the vertical,horizontal and torsional directions of the joints have been analyzed by ANSYS finite element software.The results show that the finite element analysis agrees well with the experimental results.Due to the set of Ding Tou Gong,the stress distribution of mortise-tenon joints are upgrated and the stiffness degeneration of mortise-tenon joints are eased.The structural performance of the combination of Tou-sun Ding-tou-gong mortise-tenon joints is better than that of other mortise-tenon joints.The influence on the structural performance of the number of Ding Tou Gong is not as obvious as that of its mortise-tenon forms.The research results of this paper can enrich the research content of traditional timber buildings in the South Yangtze river regions,and provide scientific theoretical basis for the protection of the Song and Yuan dynasties timber buildings in the South Yangtze river regions meanwhile provide important structure parameters and analysis method for further research on Tingtang-Style timber buildings in the South Yangtze river regions.