The mechanics of chain composites that can exhibit delocalized failure and very large values of energy absorbed per unit volume during failure are analyzed. The composites absorb energy because they are configured in such a way that chain links must displace through large distances before coming into inti- mate contact with one another, doing work continuously against the matrix. An approximate analytical model for the stresses within the chain links during link displacement is formulated and the results vali- dated by finite element analyses. The condition that the maximum stress within the links be less than the link strength leads to a criterion for transition from localized failure (involving failure of the links at small strains) to delocalized failure (with distributed damage and large plastic strains occurring via link displace- ment). The model is also proposed as a design rule for optimizing the energy absorption of this class of composites.
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