['A', 'bond', 'failure', 'is', 'thought', 'of', 'as', 'a', 'micro', '-', 'crack', 'nucleation', ',', 'specifically', 'as', 'a', 'separation', 'between', 'the', 'adjacent', 'cells', 'in', 'the', 'cellular', 'structure', 'along', 'their', 'common', 'face', '.']