ABSTRACT

This paper presents a finite element modeling method for a prediction of lateral resistance and seismic response of the roof structure of a historic Chinese timber frame building. Force-displacement relationships of straight tenon joints, Mantou tenon joints, and Dougong bracket sets are calibrated by experimental results. In-plane and out-of-plane resistance analyses have been carried out, and force-displacement relationships and stress contributions are obtained. Acceleration and displacement responses are attained and adopted for the seismic performance evaluation of the historic roof structure. Results show that the overall in-plane and out-of-plane hysteresis performances of the roof are poor and energy dissipation abilities are weak. The seismic responses of measuring nodes are close under the same seismic excitation. As the seismic excitation increases, peak responses of all measuring nodes increase. Dougong brackets and mortise-tenon connections dissipate large seismic energy under strong excitation, and seismic responses (acceleration and displacement responses) of the roof structure are significantly reduced. The maximum drift angles of the entire roof truss are found to approach 1/2500 rad, demonstrating that the roof structure has good integrity.