#Plastic lattice crack

The waiting links are not initially activated, which reduces the stiffness of an undamaged structure. The designs of impact-protecting structures with waiting links were described in. A helicoidal structure with increasing energy absorption was suggested in. Rational design of the elements of such structures against waves of damage was investigated in. The dynamics of damage was numerically investigated in the paper. Activation of these rods in a partially damaged structure increases the local stiffness and leads to distributed damage and damage waves. Dynamics and waves of damage in a chain with sacrificial links are described in. Non-localized distributed damage stage materials are especially beneficial because they allow monitoring of the structural health of the material and detecting damage before fatal collapse .Ī one-dimensional structural illustration of the idea of sacrificial links was presented in, where after partial damage of sacrificial rods, the loading was carried by the initially inactive curved rods called ‘waiting links’. įault (damage) tolerant materials are of significant interest to modern engineering practices. Similarly, some polymer materials possess distributed sacrificial links, failure of which does not destroy the material's integrity. They possess sacrificial links or soft interfaces, which fail first, while the material remains intact at a macro scale. The fault tolerance response in these materials is thanks to their specific microstructure. The prominent examples of natural fault-tolerant materials with the distributed damage stage are bone tissues and nacre. Consequently, the specimen remains intact while experiencing large irreversible deformations and large energy dissipation.

#Plastic lattice crack

We design and experimentally test a fault-tolerant material that resists crack propagation: the damage develops slowly, and the strain localization stage is preceded by a phase where damage is evenly distributed in the material volume. In both cases of brittle as well as ductile materials, the crack propagates due to strain localization. A catastrophic macro-crack propagates through a homogeneous specimen subjected to uniform tensile loading. The majority of engineering materials fail due to cracking.

This article is part of the theme issue ‘Modelling of dynamic phenomena and localization in structured media (part 2)’. The experimental results are supported by simulations which confirm that the proposed fault-tolerant material possesses excellent energy absorption properties thanks to the distributed damage stage phenomenon.

This initial distributed damage stage allows for a better energy absorption rate before the catastrophic failure of the structure.

The fatal macro-crack propagates after the distributed damage reaches a critical level. At the initial phase of damage, the thinner beams buckle then another group of separated thin beams plastically yield and rupture. Due to its morphology, the failed beams are evenly distributed in the lattice at the initial stage of damage at this stage, the material remains intact, preserves its bearing ability, and supports relatively high strains before the final failure. The lattice is subjected to uniaxial tensile loading. The specimens were three-dimensional-printed from the VeroWhite elastoplastic material. Here, we experimentally verify the fault-tolerant properties of these lattices. The proposed design consists of beam elements with two different thicknesses the lattice is macro-isotropic and stretch dominated. 89, 503–519), where its superior properties were found numerically. The morphology of such lattices was suggested in the theoretical papers (Cherkaev and Ryvkin 2019 Arch. The paper describes a fault-tolerant design of a special two-dimensional beam lattice.