{'fraction_non_alphanumeric': 0.016853932584269662, 'fraction_numerical': 0.0, 'mean_word_length': 5.6, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Mode I delamination growth of multidirectional composite laminates under fatigue loading

Fatigue delamination growth of multidirectional carbon/bismaleimide composites was investigated to disclose the specific role of ply orientations. Both fatigue crack growth rate and threshold values of strain energy release rate in Mode I were studied by double cantilever beam test. For specimens with rising delamination resistance effect, the fatigue crack growth rate was found to be dependent on normalized interlaminar energy, GI/GIC, rather than GI. The experimental data also show that the fatigue threshold Gth is almost proportional to the corresponding GIC, that is Gth /GIC is constant and hardly affected by the midplane-adjacent fiber orientation. Furthermore, fractographs revealed that the rising delamination resistance is dominantly aroused by fiber bridging and intra-ply fracture.