Table 4.

Interfacial strength parameters determined from the experimental force–displacement curve for E-glass fiber–PP matrix pair using different methods.

Method	Fd, N	Fmax, N	Fb, N	τd, MPa	τf, MPa	s × 103, N2	Rank
1 (Fd, Fmax)	0.1259	0.3296	0.3038	15.22	8.73	0.292	6
	0.2659	0.3296	0.1356	32.14	3.90	22.82	7
2 (Fd, Fb)	0.1259	0.3158	0.2867	15.22	8.24	0.191	5
	0.2659	0.4272	0.2867	32.14	8.24	9.53	5
3 (Fd, best{Fmax, Fb})	0.1259	0.3212	0.2935	15.22	8.44	0.116	2
	0.2659	0.3968	0.2419	32.14	6.95	6.53	3
4 (Fb, Fmax)	0.1455	0.3296	0.2867	17.59	8.24	0.384	7
	0.1455	0.3296	0.2867	17.59	8.24	14.50	6
5 (Fb, best{Fd, Fmax})	0.1324	0.3203	0.2867	16.01	8.24	0.130	3
	0.2183	0.2869	0.2867	26.39	8.24	5.55	2
6 (Fmax, best{Fd, Fb})	0.1344	0.3296	0.2966	16.25	8.53	0.172	4
	0.1977	0.3296	0.2304	23.89	6.62	7.83	4
7 (best { Fd, Fmax, Fb})	0.1305	0.3230	0.2918	15.77	8.39	0.091	1
	0.2282	0.3736	0.2560	27.59	7.36	4.30	1
Experimental values	0.1259	0.3296	0.2867	-	-	-	-
	0.2659

The embedded length was 629 µm, the fiber diameter was 17.6 µm. The upper value was calculated for the first kink (F_d1 = 0.1259 N); the lower, for the second kink (F_d2 = 0.2659 N).