Dynamic performance of bracket complexes used in traditional timber structures in Japan

A bracket complex is a type of bearing system located on the top of a column and transmits the vertical load of the roof to the column. Bracket complexes are often used in Buddhist temples and Shinto shrines constructed using traditional timber structure. The bracket complex, being a combination of timber blocks and beam like elements, is said to have a positive effect on the seismic performance of traditional timber structures. However, this hypothesis has not been theoretically or quantitatively proven. The aim of the present paper is to clarify the dynamic performance of the bracket complex. The investigations of the present study were performed through experiments and analysis. Shaking table tests were conducted on four different types of bracket complexes. The stiffness, natural frequency, and load-displacement relationships were determined. The results were compared with those obtained by static lateral loading tests on the same specimen by the authors in previous studies. Earthquake response analyses were carried out by applying a structural model proposed by the authors based on the results of static lateral loading tests. The results of the analysis and shaking table tests are compared, and the validity of the proposed structural model is discussed.