Abstract:
This paper analyses the viability of Janka hardness as an estimator of density, compression strength and modulus of rupture. This test is considered non-destructive since wood tested does not suffer significant damage. The 361 Brazilian native hardwood and conifers species logs data were analyzed using a exponential function for Janka hardness and the following dependent variables: density, flexural and compression strength. It was observed that the dispersions around the regression curves increase, but on the transformed scale these
dispersions are constant. The regression analysis results showed that there is a correlation of apparent density properties at 15% of moisture content, flexural strength and green state compression with the Janka hardness on green wood. Native woods presented regression curve with a coefficient of determination between 0.85 and 0.86, with dispersion between 11% and 16%. It was concluded that the Janka hardness property can be used as density estimator and resistance to flexion and compression.
Reference:
YOJO, Takashi; SOUZA, Cassiano Oliveira de; MIRANDA, Maria José de Andrade Casimiro; BRAZOLIN, Sérgio. Dureza Janka como estimador da densidade aparente e das resistências à flexão e compressão em madeiras de folhosa nativas brasileiras e coníferas. In: ENCONTRO BRASILEIRO MEM MADEIRAS EM ESTRUTURAS DE MADEIRA, EBRAMEM, 16.; CONGRESSO LATINO-AMERICANO DE ESTRUTURAS DE MADEIRAS, 3., 2018, São Carlos. Anais… São Carlos: USP/EEESC; IBRAMEM, 2018. 8 p.
Access to the article on the event website:
http://soac.eesc.usp.br/index.php/ebramem/xviebramem/paper/view/1106/675
This paper analyses the viability of Janka hardness as an estimator of density, compression strength and modulus of rupture. This test is considered non-destructive since wood tested does not suffer significant damage. The 361 Brazilian native hardwood and conifers species logs data were analyzed using a exponential function for Janka hardness and the following dependent variables: density, flexural and compression strength. It was observed that the dispersions around the regression curves increase, but on the transformed scale these
dispersions are constant. The regression analysis results showed that there is a correlation of apparent density properties at 15% of moisture content, flexural strength and green state compression with the Janka hardness on green wood. Native woods presented regression curve with a coefficient of determination between 0.85 and 0.86, with dispersion between 11% and 16%. It was concluded that the Janka hardness property can be used as density estimator and resistance to flexion and compression.
Reference:
YOJO, Takashi; SOUZA, Cassiano Oliveira de; MIRANDA, Maria José de Andrade Casimiro; BRAZOLIN, Sérgio. Dureza Janka como estimador da densidade aparente e das resistências à flexão e compressão em madeiras de folhosa nativas brasileiras e coníferas. In: ENCONTRO BRASILEIRO MEM MADEIRAS EM ESTRUTURAS DE MADEIRA, EBRAMEM, 16.; CONGRESSO LATINO-AMERICANO DE ESTRUTURAS DE MADEIRAS, 3., 2018, São Carlos. Anais… São Carlos: USP/EEESC; IBRAMEM, 2018. 8 p.
Access to the article on the event website:
http://soac.eesc.usp.br/index.php/ebramem/xviebramem/paper/view/1106/675
