Hysteretic behaviors of Pingshenke Dou-Gong brackets of ancient timber buildings under different loading directions

Abstract

To study the effect of loading directions on the seismic behavior of Dou-Gong bracket, numerical analysis was conducted on two Pingshenke Dou-Gong brackets under the overhanging direction (DG-1) and width direction (DG-2). The simulated hysteretic characteristic, stiffness degradation, and energy dissipation of Dou-Gong brackets were compared and validated by the test results. The horizontal displacement and relative slip of Dou-Gong components were discussed. Besides, parameter analyses considering the loading direction, wood grain direction, and material properties were performed. Results indicate that DG-2 has higher stiffness, bearing and energy dissipation capacity than DG-1, but poor deformation capacity. The positive component displacement of DG-1 is greater than DG-2, while the negative is the opposite. The relative slip between Da-Dou and Pingban-Fang is larger than other components. The overhanging and width direction are the most adverse direction for DG-1 under positive and negative load, respectively. DG-1 has the largest bearing capacity when Da-Dou is friction in the longitudinal surface under the tangential grain direction, but the grain direction has little influence on DG-2. The larger the friction coefficient and compressive strength, the greater the bearing capacity, but the initial stiffness is not improved. The elastic modulus has little effect on the initial stiffness and bearing capacity of Dou-Gong bracket.