Study on anti-seismic mechanism of Chinese timber frame structure building and computational simplification modeling of bracket set based on ABAQUS

Chinese ancient timber frame structure building shows excellent anti-seismic capacity during its long history. Different from the anti-seismic design conception of modern reinforced concrete building, the timber structure takes advantage of structural nonlinearity instead of material nonlinearity. This thesis introduces the structural features of Chinese ancient timber frame structures contributing its aseismatic capacity and discusses the anti-seismic mechanism of each feature. The mortise-tenon joint and bracket set are two main characteristics of Chinese ancient timber frame structures. The FEM numerical analysis in ABAQUS is investigated for timber frames and bracket sets, which are taken from a typical example of this type building, the gate of Dule Temple, in Ji County, China. Quasi-static simulation is carried out with applying lateral loading step by step under vertical pressure. The M-θ relationship of mortise-tenon joint and P-△ relationship of bracket set shows ideal nonlinearity. Because of the complexity of bracket set structure, a beam-element modeling in SAP2000 is suggested to simplify the computational modeling, i e., allocating beams along the internal force transfer path, and simplifying the bracket sets into inclined struts and trusses. A reference model is created for verify the accuracy of simplification method, which simulates the mortise-tenon joint and bracket set using nonlinear spring taking values from ABAQUS analysis results. Comparison of modal analysis and seismic analysis with response spectrum method shows similar results and same assessment is gotten, which prove the proposed simplification method for bracket set is sufficient for seismic analysis.