Experiments on laminated bamboo lumber nailed connections

Abstract

Laminated bamboo lumber (LBL) nailed connection made with LBL main member and sandwiched by LBL side members is introduced, which plays an essential role in the safe and reliability of bamboo buildings. However, little research attention has been paid on to the mechanical behavior of connections. This paper reports an experimental study on the effect of parameters on reference loads (yield load and maximum load), stiffness and load-slip behavior of the connections, including nail diameter, number of lines and rows of nails. For single nail connection, nail pull-through and plastic hinges forms in LBL members. Mode cross-over from ductile response to brittle failure is observed in multi-nail connections with one or more splitting cracks develop from the nails hole edges toward the ends of the side or middle members. A decreasing ductility of connections is investigated with increasing diameter and number of nails. The capacity of effective number of nails in a row is evaluated and compared with that obtained from existing analytical formulas. Predictions from existed various theoretical modes are compared with experimentally determined capacities of nailed connection per shear plane per nail and conclude that the load carrying capacity of connections with laterally load nails can be applied to accurately estimate using European yield models (EYMs). Furthermore, the model developed by Folz is capable of predicting the load-slip relationship of LBL nailed connections. The findings of this study will provide the scientific basis and useful information for the design and finite element numerical simulation of engineered bamboo structures containing LBL nailed connections and promote the rational use of bamboo resources in the field of civil engineering.