Numerical Modelling Strategies for Column Rocking Behavior in Traditional Timber Structures

ABSTRACTAs a typical feature of traditional Chinese timber structures, columns with floating foot joints are prone to rocking under horizontal force. The column rocking behavior plays an important role in resisting lateral loads. This paper proposes modelling strategies for the rocking behavior of traditional timber columns. The proposed model can capture the contact state of the column foot via a series of distributed axial springs and the possible sliding via a horizontal spring. It has a lower computational cost than refined finite element (FE) models and is independent of numerical calibration compared to rotational spring models. The modelling strategies were validated against refined FE models and experimental data available in the literature. The principle behavior of the approach was carefully investigated including contact stiffness, distribution modes, spring numbers, column bending effects, and computational efficiency. Results show that the effective compression height of the column foot can take the value of the column radius to determine spring stiffness. Column bending needs to be considered in the mechanical analysis of column foot joints for slender columns. The case study on the lateral stiffness of traditional timber frames confirms the applicability of the proposed model in the structural analysis of ancient timber buildings.KEYWORDS: column foot jointscolumn rockingmulti-spring modelnumerical modellingtraditional timber structures AcknowledgmentsThis work was supported by the National Key Research and Development Program of China under Grant No. 2017YFC0703503.Disclosure statementNo potential conflict of interest was reported by the author(s).