Three-dimensional finite element analysis of the Japanese traditional post-and-beam connection

Abstract

A three-dimensional finite solid element model for Japanese traditional post-and-beam connections was developed using the wood foundation method, which employed the concept of a beam on a nonlinear foundation. The wood foundation in the model was a three-dimensionally prescribed zone surrounding a nail shank in order to address the intricate wood crushing behavior induced by nail slip. Material models for the wood members and the foundation were developed based on the transversely isotropic plasticity from the software package ANSYS. The Japanese post-and-beam connection modeled was a ten-nail multiple connection with a mortise and tenon joint and is called the CPT (Corner Plate, T-shaped) connection. Details of the model development are presented. As a feasibility study, blind predictions of the model were compared with available connection test data and showed good results for predicting the progress of the load-deformation relations in three dimensions. However, the limitation of the model was found in simulating fracture failures such as wood splitting or nail tear-out from the wood. Model applications and the need for model improvement are discussed.