Analytical Model of Bracket Set Frame in Traditional Chinese Timber Structures

Bracket set frame (BSF) consists of two column-head bracket sets (CHBSs) and one beam (Tiaojianliang), CHBS consists of bearing blocks (Dou) and short beams (Gong), in a unique manner in traditional Chinese timber structures. The mechanical performances of a BSF is different from a rigid joint or hinge joint exhibiting the behavior of a semi-rigid joint. An analytical model of BSF along y-axis direction of a building is proposed. Based on the structural form of BSF, the analytical model of a BSF is composed of rotational spring elements representing the Mantousun (MTS), Dadou with mortise (DDM) and beam elements representing the beams (Gong, Fang and Tiaojianliang). The accuracy of this model is validated with a solid element model with the same geometric dimensions and mechanical parameters. Effects of the vertical load and section dimension of Tiaojianliang on the load resistance capacity of BSF are analyzed. Result suggests that the load resistance capacity of BSF will increase significantly with the vertical load increases. The load resistance capacity of BSF will decrease with the section dimension of Tiaojianliang decreases.