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

Table 2

Critical load, 𝑃_cr, and corresponding displacement, δ _cr, for the measured crack length of a DCB specimen made of angle ply 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
47	74.56	5.89	73.13	5.80	1.92	1.54	73.13
48	73.84	6.31	71.60	6.05	3.03	4.15	71.60
49	71.18	6.55	70.14	6.30	1.46	3.69	70.14
50	68.18	6.68	68.74	6.56	−0.82	1.75	68.74
51	64.42	7.01	67.39	6.83	−4.61	2.56	67.39
56	59.72	8.09	61.37	8.24	−2.77	−1.75	61.37
61	58.76	10.07	56.34	9.77	4.11	2.91	56.34
66	51.56	11.61	52.08	11.44	−1.00	1.42	52.08
71	49.01	12.83	48.41	13.24	1.24	−3.23	48.41

Layup: [±45]₃, 𝐵=25 mm, 2ℎ=6.36 mm, 𝑎_𝑜=46 mm, 𝐸=12.9 GPa, 1/𝐾→0, and 𝐺_Ic=543 J/m².