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Bioinspired by an extremely tough biocomposite, nacre, found inside certain seashells, we perform finite-element calculations of the layered structure in the presence of a crack. Generally, such a crack deprives materials of strength since the stress is highly concentrated at the tips of a crack as demonstrated on the right (color stands for the stress intensity). Our results for the model composite revealed that the crack-tip stress is significantly reduced, following a simple scaling law.