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Table 4 Calculations details of the adequacy of the model, case of power model

From: Effect of the loading duration on the linear viscoelastic parameters of tropical wood: case of Tectona grandis L.f (Teak) and Diospyros mespiliformis (Ebony) of Benin Republic

y exp Ycal ei= y exp – Y cal e i 2 d = y exp y exp ¯ d 2 d i
  Case of Tectona grandis L.f  
8.23 7.97 0.2555 0.065 1.954 3.819 0.021
7.49 7.38 0.1068 0.011 1.214 1.474 0.009
6.92 6.99 −0.0705 0.005 0.644 0.415 −0.006
6.56 6.70 −0.1403 0.020 0.284 0.081 −0.011
6.3 6.47 −0.1722 0.030 0.024 0.001 −0.014
6.16 6.29 −0.1254 0.016 −0.116 0.013 −0.010
6.06 6.13 −0.0679 0.005 −0.216 0.047 −0.006
5.96 5.99 −0.0323 0.001 −0.316 0.100 −0.003
5.88 5.87 0.0065 0.000 −0.396 0.157 0.001
5.78 5.77 0.0119 0.000 −0.496 0.246 0.001
5.71 5.67 0.0365 0.001 −0.566 0.320 0.003
5.65 5.59 0.0621 0.004 −0.626 0.392 0.005
5.6 5.51 0.0902 0.008 −0.676 0.457 0.007
5.56 5.44 0.1220 0.015 −0.716 0.512 0.010
  Case of Diospyros mespiliformis  
6.29 6.08 0.214 0.046 0.904 0.817 0.0228
5.84 5.86 −0.024 0.001 0.454 0.206 −0.0026
5.62 5.69 −0.072 0.005 0.234 0.055 −0.0076
5.45 5.55 −0.096 0.009 0.064 0.004 −0.0102
5.34 5.42 −0.081 0.007 −0.046 0.002 −0.0086
5.27 5.31 −0.041 0.002 −0.116 0.014 −0.0044
5.2 5.21 −0.014 0.000 −0.186 0.035 −0.0015
5.14 5.13 0.013 0.000 −0.246 0.061 0.0014
5.09 5.05 0.042 0.002 −0.296 0.088 0.0045
5.03 4.98 0.055 0.003 −0.356 0.127 0.0058
4.98 4.91 0.071 0.005 −0.406 0.165 0.0075
  1. Where,
  2. y exp : creep value obtained experimentally;
  3. Ycal: creep value calculated using the model; y exp ¯ sample means of observations; d i = e i σ ^ 2 : standardized residual; σ ^ 2 : variance.