Influence of Root Rotation on Delamination Fracture Toughness of Composites

Table 1

Comparison of mode-I delamination fracture toughness of glass/epoxy composite by different data reduction schemes.

Test results [15]			Critical energy release rate, (J/m^2)
Crack length, (mm)	(N)	(mm)	Modified beam analysis	Compliance method	FEM; (linear analysis)	Berry method	Present (9)
33.45	38.93	3.54	234	229	229	244	244
41.30	35.63	5.47	299	292	323	280	290
50.80	31.63	8.93	355	348	381	332	343
60.59	28.21	14.08	400	392	427	392	398
70.33	25.11	19.42	424	418	453	413	423
79.87	23.11	26.87	459	456	490	464	470
89.29	21.6	35.03	495	498	532	505	512
98.56	20.31	44.04	524	536	573	541	550
107.80	19.16	53.14	548	569	607	563	577
116.60	18.33	64.28	570	609	649	603	617

Lay-up: 0₂₂,   mm,  mm, and .7 GPa.