Predicting flexural properties of six Amazonian hardwoods using stress wave nondestructive method [Estimativa das propriedades de flexão estática de seis espécies de madeiras Amazônicas por meio da técnica não-destrutiva de ondas de tensão]
del Menezzi C.H.S.,University of Brasilia |
Silveira R.R.,University of Brasilia |
de Souza M.R.,Servico Florestal Brasileiro SFB
Acta Amazonica | Year: 2010
The utilization of non-destructive testing (NDT) can augment the technological information about well-known wood species, as well as those which have not yet been investigated. The main advantage is that NDT methods are fast, and many measures can be undertaken to improve the confidence level of the evaluation. In this context, the paper aims to study the feasibility of the stress wave method to estimate flexural properties of six Brazilian tropical woods. The species were chosen according to density: Balfourodendron riedelianum, Cedrela fissilis, Cordia goeldiana, Bowdichia virgilioides, Dipteryx odorata and Tabebuia sp. Twenty samples from each species were cut and tested according to ASTM D143-94 (2000) to determine flexural properties, totaling 120 samples. Before mechanical testing, the samples were non-destructively tested by using the stress wave method, and their dynamic modulus of elasticity (Ed) and wave velocity (wv) were determined. Stepwise multiple linear regression analysis was run to select the best variables for estimating the flexural properties. According to the results, the models generated had higher values of R2. Thus, it can be concluded that the stress wave method is suitable for predicting flexural properties where there is wood variability, for instance among species. On the other hand, when the variability is low, for instance within wood species, the models generated had low predictability.