Individual data of basic density and modulus of rupture at static bending at wet condition and at 12% of humidity were obtained from 150 Amazonian wood species collected in the regions of State of Amapá, State of Amazonas and State of Pará.
The properties variability was determined for each region as well as for the whole Amazonian rain forest.
The probabilistic density and cumulative density functions from the Weibull's distribution were adjusted to the basic density, the observed modulus of rupture and to the modulus of rupture estimated from its correlation with basic density.
The variability of the studied properties for each region is similar to the whole Amazonian rain forest and the variability of observed modulus of rupture is the same as the estimated from its correlation with the basic density.
The theory developed in this work allows to evaluate the wooden structure safety by using the values and the Weibull's distribution of basic density.
The safety coeficient related to bending stress adopted by the Brazilian standart for wooden structures is extremely high, which permit to obtain 99,98% of probability of success.
Key words: tropical wood, basic density, mechanical properties, structural safety.
Correspondence: Jose Nivaldo García, ESALQ/USP - Departamento de Ciencias Florestais, Av. Padua Dias, 11 - Caixa Postal 9, 13418-900 - Piracicaba/SP - Brasil
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