EXPERIMENTAL STUDY ON LATERAL STIFFNESS OF DOUGONG LAYER IN CHINESE HISTORIC BUILDINGS
Through low cyclic loadings of single Dougong,two Dougongs and four Dougongs,the degradation of the lateral stiffness of Dougong was studied.According to the test,the hysteresis curve and skeleton curve of force-displacement were obtained and the formula of resilience model and mechanical model were established.From the experiment,it is by all appearances that slippage is the main deformation of Dougong.Energy dissipation due to frictional slippage is an important reason for the excellent seismic behavior of ancient wooden structures.Hysteretic loops of Dougong give the appearance of parallelogram.Plump area of the hysteretic loop accounts for its excellent ability of energy dissipation performance.The mechanics model of Dougong belongs to linear strengthening elastic-plastic model.Both the fitting equation of force-displacement and resilience model reflect the changes in the stiffness of Dougong,and can be used to the research on static load delivery as well as dynamic structural analysis and calculation of similar wooden structures.