. 2020 Nov 3;10:18916. doi: 10.1038/s41598-020-76021-5

Table 2.

Stepwise regression results for compression and impact testing.

Test	Parameter	V.Th	V.Sp	Conn.D	Regression statistics
Quasi-static	k	76.49	− 11.79	− 1728	R² = 0.8525, p < 0.001
	k	< 0.001	< 0.001	0.012	R² = 0.8525, p < 0.001
	E_A	1.24	− 0.19	− 37.70	R² = 0.8380, p < 0.001
	E_A	< 0.001	< 0.001	< 0.001	R² = 0.8380, p < 0.001
	W_S	105.3	− 15.24	− 1915	R² = 0.8652, p < 0.001
	W_S	< 0.001	< 0.001	0.045	R² = 0.8652, p < 0.001
Impact	F_impact	214.7	98.99	–	R² = 0.9701, p < 0.001
	F_impact	< 0.001	< 0.001	–	R² = 0.9701, p < 0.001
	E_S =	1.32	0.18	24.26	R² = 0.9907, p < 0.001
	E_S =	< 0.001	< 0.001	0.004	R² = 0.9907, p < 0.001
	W_S	26.20	48.80	7644	R² = 0.9643, p < 0.001
	W_S	0.065	< 0.001	< 0.001	R² = 0.9643, p < 0.001

The dependent variables were the stiffness (k), energy stored (E_S), the specific energy stored (W_S), and the impact force (F_Impact). The independent variables were velar thickness (V.Th), velar spacing (V.Sp), and connectivity density (Conn.D). The p-values for each regression coefficient are shown in italics.