Fracture Energy Estimation of DCB Specimens Made of Glass/Epoxy: An Experimental Study

Table 1

Critical load, 𝑃_cr, and corresponding displacement, δ _cr, for the measured crack length of a DCB specimen made of unidirectional glass/epoxy composite.

Test results			Present analysis
Crack length, 𝑎 (mm)	𝑃 (N)	δ (mm)	𝑃cr (N) (12)	δ cr (mm) (8)	% Relative error in		𝑃max, (18)
					Load	Displacement
44	127.77	6.22	138.15	6.47	−8.13	−4.11	161.77
45	125.89	6.33	135.49	6.74	−7.63	−6.37	158.18
46	125.41	6.68	132.93	7.01	−6.00	−4.88	154.74
47	123.16	6.94	130.46	7.28	−5.93	−4.92	151.45
48	121.15	7.21	128.09	7.56	−5.73	−4.83	148.29
53	118.99	9.19	117.42	9.03	1.32	1.69	134.30
58	117.13	11.48	108.41	10.63	7.45	7.40	122.72
63	108.78	13.29	100.68	12.36	7.45	7.05	112.98
68	104.84	15.73	93.99	14.21	10.34	9.66	104.68

Layup: [0]₆, 𝐵=25 mm, 2ℎ=5.86 mm, 𝑎_𝑜=43 mm, 𝐸=36 GPa, 𝐾=231 Nm, and 𝐺_Ic=1075 J/m².