Table 2.

The formulas for calculation of the compression and tensile modulus.

	Formula	Explanations
Compressive modulus	Compressive stress $\sigma =\frac{F}{A}\left[\mathrm{MPa}\right]$ Nominal strain $\epsilon =\frac{\mathsf{\Delta }L}{L}$	F—force [N] A—initial cross sectional area measurement [mm2] L—the initial distance between the compression plates [mm] ΔL—the decrease in the distance between the plates after the test [mm]
Tensile modulus	Tensile stress $\sigma =\frac{F}{A}\left[\mathrm{MPa}\right]$ Nominal strain $\epsilon =\frac{\mathsf{\Delta }L}{L}$ $Et=\frac{{\sigma }_2-{\sigma }_1}{{\epsilon }_2-{\epsilon }_1}\left[\mathrm{MPa}\right]$	F—force [N] A—initial cross sectional area measurement [mm2] L—the initial distance between the grips [mm] ΔL—the increase in the distance between the grips after the test [mm] σ1—the stress in MPa measured at a strain of 0.0005 (ε1) σ2—the stress in MPa measured at a strain of 0.0025 (ε2)