Computational Modeling of Laminated Veneer Bamboo Dowel Connections

Abstract

Laminated veneer bamboo (LVB) is a relatively new building product made from layers of glued bamboo and used in applications similar to lumber. Few studies exist on its mechanical performance; in particular, its failure behavior in dowel-type connections. This study uses both experimental and numerical methods to shed light on the complex stress state of an LVB dowel connection when progressively loaded in compression parallel to grain. A 2D elastic, plane strain finite element model is developed for a 15.9-mm (5/8-in.)-diameter bolt with a bolt hole size of 17.5 mm (11/16 in.) following the associated ASTM standard for full-hole specimen protocol. Experimental tests are used to validate and calibrate the model. Results show that predominant failure occurs off-center of the bolt contact region where the shear stress-to-strength ratio governs. Tensile stress perpendicular to grain, often the primary cause of wood failure, is found to be an influential secondary cause of failure. In addition, a frictional contact analysis leads to the finding that the coefficient of friction is a key factor in predicting shear stress.