Experimental Study On Mortise-Tenon Joints And Its Strengthened Effect In Chinese Ancient Wooden Building

Chinese traditional building holds a very important position in the world, especially for wooden structure. It has long history, large quantity, complex structure, rich scientific and cultural content, and excellent seismic behaviors. The mortise-tenon is a great architectural invention which can improve the mechanical performance of ancient wooden building. However, large numbers of exiting ancient wooden buildings have been in service for lots of years and their structures have been greatly damaged. Therefore, it is necessary to find out a reasonable strengthened method for Chinese Ancient Wooden Building.In this paper, based on an low-cyclic reversed loading experiment of three wooden frame models which were made in accordance with the requirements by Ying Zao Fa Shi (Building Standards) of Song dynasty, the test of 6 joints strengthened with CFRP sheets and 4 joints strengthened with flat steels plates, the pull-out length of the mortise-tenon, failure patterns of the reinforcing materials and the hysteretic curves of the mortise-tenon joints were obtained. Through the analysis on the hysteretic curves and its skeleton curves of the joints, the bearing capacity, ductility, energy dissipation capacity, stiffness and restoring-force model were established. The test results show that a good effect can be achieved with the joints reinforced by CFRP sheets and flat steel plate. According to mechanical analysis and test, the formula for calculating the mortise-tenon joints and the joints reinforced by CFRP sheets and flat steel plate can be deduced, which provide the theoretical supports for the seismic design and strengthened method of ancient wooden buildings.