Evaluation method for embedment stiffness of metal washers in bolted timber joints using torque gradient and nut factor

Journal of Wood Science

Official Journal of the Japan Wood Research Society

Table 3 Comparison of calculated and experimental values

Specimen	Number	T_f/φ [Nm/deg]	K_ew-cal.1^a [kN/mm]	K_ew-cal.2^b [kN/mm]	K_ew-exp [kN/mm]	K_n-cal
Japanese cedar	1	0.373	18.6	28.3	21.4	0.32
	2	0.393	19.7	30.1	21.2	0.34
	3	0.388	19.4	29.7	22.3	0.33
	4	0.368	18.3	27.9	22.0	0.31
	5	0.288	14.1	21.4	22.2	0.24
	6	0.308	15.2	23.0	18.4	0.31
Hiba	1	0.509	26.1	40.4	24.9	0.38
	2	0.351	17.4	26.5	25.1	0.26
	3	0.437	22.1	33.9	24.9	0.33
	4	0.440	22.3	34.2	25.1	0.33
	5	0.442	22.4	34.3	25.6	0.33
	6	0.431	21.8	33.4	25.1	0.32
Japanese cypress	1	0.577	30.0	46.8	30.4	0.36
	2	0.722	38.8	61.5	30.0	0.46
	3	0.820	45.0	72.2	33.4	0.48
	4	0.682	36.3	57.3	32.1	0.41
	5	0.684	36.4	57.5	32.5	0.41
	6	0.705	37.7	59.8	31.7	0.43