MECHANICAL PERFORMANCE IN FLEXURE FOR TWO SPANS OF TRUSSES FROM <em>HIERONYMA</em> <em>ALCHORNEOIDES</em> AND <em>GMELINA</em> <em>ARBOREA</em> WOODS FASTENED WITH NAILS AND SCREWS

Abstract

The present study had the objective of determining the behaviour of Pratt-type trusses made from Gmelina arborea and Hieronyma alchorneoides lumbers relative to loads, displacement and design load stiffness using two types of fasteners (nails and screws) for two spans (6 and 9 m). It was found that the maximum load values were greater in H. alchorneoides lumber trusses than G. arborea. Design strain values showed that trusses fabricated with H. alchorneoides wood had higher design properties than G. arborea. The trusses with a 6-m span showed strength and design strain values greater than those with a 9-m span, but lower displacement values. No significant differences appeared in the different types of fastener used. Nonetheless, the load vs. strain behaviour suggested that trusses fabricated with screws presented better properties than those fastened with nails.