Theoretical and experimental deflections of glued laminated timber beams made from a tropical hardwood

Abstract

Nondestructive testing (NDT) can play an important role in improving the quality and reliability of tropical hardwood as an engineering material. By means of these methods, the stiffness of the material can be determined and the information used to improve its structural performance. Although, it is a usual approach for qualifying the material used to manufacture engineered wood products made mainly from softwoods, it is not so common for tropical hardwoods. Additionally, the lack of information regarding properties of glulam beam made from these kinds of wood is evident. In this context, the paper aimed at evaluating the theoretical and experimental deflection of glulam beams made from the Brazilian hardwood lourovermelho (Sextonia rubra). Initially, the stiffness of each lamina was determined nondestructively using transverse vibration method (E dtv ), which has been demonstrated to be the most suitable method for this wood species. Then, ten 5-lamina glulam beams were assembled according to descending lamina E dtv values. The experimental evaluation was performed using a four-point bending schedule. In general, the theoretical values of deflection were 2% higher than the experimental ones. The transverse vibration showed to be a suitable method to both measure lamina stiffness and predict glulam beam deflection.

Glued laminated Timber Produced with Tropical Brazilian Wood Species

“…Teles et al [18] comparing theoretical and experimental deflections of glued laminated timber beams, made with a tropical essence (Sextonia rubra), among their conclusions confirm that the cited wood specie can be employed as raw material for GLT production.…”

The Usefulness of Pine Timber (Pinus sylvestris L.) for the Production of Structural Elements. Part II: Strength Properties of Glued Laminated Timber

“… * Modulus of rupture (MOR)—characteristic value according to EN 14,080 [ 47 ], ** CoV (coefficient of variation). …”

“…However, they pointed out that the quality of the steel-wood joint was of significant importance in these systems. The abovementioned authors draw attention to systems made of different lamella qualities; however, there is the possibility of having the lamellas be joined in their width [ 44 , 45 ] or having them made of different species [ 46 , 47 ]. The created systems result from certain fixed concepts, as described in appropriate standard or the model described in the works of Fink [ 48 ], Foschi and Barrett [ 49 ], or Hernandez et al [ 50 ] may be the basis for their creation.…”

Mechanical Properties of Glued-Laminated Timber with Different Assembly Patterns

“…Anshari et al [12] proposed a new approach to strengthen glulam beams which was tested under bending. Teles et al [13] performed a nondestructive test to assess the deflection of glulam beams made from hardwood. Rohanova and Lagana [14] made a description on quality parameters and the according requirements of structural timber.…”