Developing advanced materials and structures based on the concept of topological interlocking

This paper presents an extensive numerical study on the impact behaviour of plate-like assemblies made of interlocking concrete bricks. In the proposed 3D finite element model, a damage based concrete model is employed with considerations of strain rate effect and concrete failure criteria. Boundary conditions are appropriately defined to simulate various initial loading scenarios. The impact responses of both monolithic and assembly plates are investigated, and the numerical model is validated by comparing the predicted results with experimental data. Compared to the monolithic plate, the structural flexibility, energy absorption capacity and the tolerance to local failure are improved in the assembly plates made of interlocking bricks. A comparative study is also carried out on the assembly plates made of two types of interlocking bricks including osteomorphic brick with two curved side surfaces and newly designed interlocking brick with four curved surfaces. It is found that the plate made by the newly developed interlocking brick exhibits less deflection and absorbs more energy than the existing osteomorphic brick.

In this paper we study a new type of interlocking brick recently proposed by the authors. The brick has a symmetrical geometry with four concavo-convex side surfaces for the interlocking purpose. Drop weight tests have been conducted to investigate the mechanical response of interlocking assembly plates by applying different levels of impact force and lateral confining load. The results show that, compared with monolithic plates, the new interlocking assembly plates have significantly improved flexural performance in terms of impact energy absorption capacity. The fracture of individual bricks during the impact always occurs along a load transmission path that is determined by the geometrical constraints of the interlocking bricks. Most importantly, the interlocking design of the plate-like assembly can effectively prevent the propagation and spread of the cracks, so that the damage to a single brick will not lead to a catastrophic failure of the entire structure.