Abstract:
An important factor affecting the strength and ultimate load of
wood structures is the strength, stiffness and durability of its
joints. Therefore, the behavior of nailed joints must be given proper
consideration when designing and analyzing wood structures. Presently,
formulas for determining the strength of nailed joints under withdrawal
loads, as outlined in the National Design Specifications and the
Uniform Building Code, are based on the statistical regression between
maximum withdrawal load (W) and the material properties of the wood and
nail.
New models were developed which predict W, withdrawal resistance
(WR) and withdrawal stiffness (WK) based on the actual forces responsible
for holding the nail in the wood. These include a normal force
to the nail due to the elastically compressed wood around the nail and
the resulting friction between the wood and nail surfaces. The
accuracy of these models were compared to the accepted formulas in the
design codes and were found to be superior in predicting W, WR and WK.
