Official Journal of the Japan Wood Research Society
From: Property gradients in oil palm trunk (Elaeis guineensis)
Properties | In relationship with density, ρ (kg/m3) | In relationship with 1-r/R | In relationship with modulus of elasticity | ||||
---|---|---|---|---|---|---|---|
Linear | Power law | Linear | Power law | Linear | Power law | ||
ρ(kg/m3) (n = 65) | Equation | – | – | \( \rho = - 153(1 - r/R) + 374 \) | \( \rho = 237(1 - r/R)^{ - 0.27} \) | – | – |
R 2 | – | – | 0.60 | 0.66 | – | – | |
SSE | – | – | 60,648 | 47,890 | – | – | |
\( {\text{WU}}(\% ) \) (n = 59) | Equation | \( {\text{WU}} = 3 9 6 9 8\; ( 1 / { }\rho )+ 7 0 \) | \( {\text{WU}} = 9 0 3 4\; ( 1 / { }\rho )^{ 0. 6 7} \) | \( {\text{WU}} = 9 0\; ( 1- r/R )+ 1 5 9 \) | WU = 241(1 - r/R)0.22 | – | – |
R 2 | 0.50 | 0.47 | 0.50 | 0.49 | – | – | |
SSE | 32,813 | 34,727 | 33,521 | 33,100 | – | – | |
SR(%) (n = 59) | Equation | \( {\text{SR}} = 0. 0 6\;\rho \, - 4. 8 8 \) | \( {\text{SR}} = 0. 0 0 0 2\;\rho^{ 1. 8 9} \) | \( {\text{SR}} = - 3.96\, (1 - r/R )+ 13.77 \) | \( {\text{SR}} = 8. 6 9 ( 1 { - }r/R )^{{{ - 0} . 2 6}} \) | ||
R 2 | 0.28 | 0.37 | 0.04 | 0.06 | – | – | |
SSE | 982 | 1328 | 1367 | 1446 | – | – | |
MOR(MPa)(n = 65) | Equation | MOR = 0.08ρ - 15.2 | \( {\text{MOR}} = 8 \times 10^{ - 7} \rho^{2.82} \) | \( {\text{MOR}} = - 13.51 (1 - r/R )+ 15.66 \) | \( {\text{MOR}} = 4. 0 1 ( 1- r/R )^{ - 0. 8 3} \) | \( {\text{MOR}} = 0. 0 0 6 ( {\text{MOE) }} + 0. 8 2 \) | \( {\text{MOR}} = 0. 0 0 6 4 ( {\text{MOE)}}^{ 1. 0 1} \) |
R 2 | 0.86 | 0.86 | 0.62 | 0.69 | 0.82 | 0.81 | |
SSE | 162 | 168 | 430 | 376 | 199 | 212 | |
MOE(MPa) (n = 65) | Equation | \( {\text{MOE}} = 1 0. 3 2 { }\rho - 1 8 2 9 \) | \( {\text{MOE}} = 0.002\rho^{2.32} \) | \( {\text{MOE}} = - 153 (1 - r/R )+ 374 \) | \( {\text{MOE}} = 631.5\; (1 - r/R )^{ - 0.71} \) | ||
R 2 | 0.66 | 0.73 | 0.48 | 0.64 | – | – | |
SSE | 8,127,401 | 8,344,221 | 12,597,622 | 10,336,166 | – | – | |
\( \sigma_{//} ( {\text{MPa)}} \) (n = 63) | Equation | \( \sigma_{ / /} = 0.039\rho - 7.19 \) | \( \sigma_{ / /} = 6 \times 10^{ - 7} \rho^{2.76} \) | \( \sigma_{ / /} = { - }6.86 (1{ - }r/R )+ 8.03 \) | \( \sigma_{ / /} = 2.1 (1 - r/R )^{ - 0.82} \) | \( \sigma_{ / /} = 0.0097 (E_{//} )+ 0.80 \) | \( \sigma_{ / /} = 0.029 (E_{//} )^{0.85} \) |
R 2 | 0.80 | 0.78 | 0.63 | 0.66 | 0.82 | 0.82 | |
SSE | 55 | 70 | 104 | 84 | 50.3 | 48.8 | |
\( E_{//} ( {\text{MPa)}} \) (n = 63) | Equation | \( E_{ / /} = 3.13\rho - 569.44 \) | \( E_{ / /} = 8 \times 10^{ - 5} \rho^{2.67} \) | \( E_{ / /} { = } - 5 3 4 ( 1- r/R ) { + 644} \) | \( E_{ / /} = 176.9 (1 - r/R )^{ - 0.75} \) | – | – |
R 2 | 0.60 | 0.64 | 0.44 | 0.49 | – | – | |
SSE | 991,353 | 1,136,873 | 1,379,713 | 1,138,552 | – | – | |
\( \sigma_{ \bot } ( {\text{MPa)}} \) (n = 59) | Equation | \( \sigma_{ \bot } = 0.0023\rho - 0.05 \) | \( \sigma_{ \bot } = 0.0036\rho^{0.91} \) | \( \sigma_{ \bot } { = } - 0. 4 4 5 ( 1- r/R ) { + 0} . 9 0 \) | \( \sigma_{ \bot } = 0.53 (1 - r/R )^{ - 0.27} \) | – | – |
R 2 | 0.40 | 0.43 | 0.42 | 0.41 | – | – | |
SSE | 1.53 | 1.54 | 1.46 | 1.23 | – | – | |
\( \tau_{//} ( {\text{MPa)}} \) (n = 118) | Equation | \( \tau_{//} = 0.004\rho + 0.02 \) | \( \tau_{//} = 0.005\rho^{0.94} \) | \( \tau_{//} = - 0.48 (1 - r/R )+ 1.33 \) | \( \tau_{//} = 0.88 (1 - r/R )^{ - 0.22} \) | ||
R 2 | 0.37 | 0.33 | 0.18 | 0.18 | – | – | |
SSE | 5.81 | 5.83 | 7.60 | 7.27 | – | – |