Our research into rock mechanics covers fractures, in situ stress reconstruction and materials and structures with interlocking.

Topologically interlocking osteomorphic blocks for multi-purpose construction

The use of interlocking blocks began in the early 1980s with the introduction of segmental masonry units for construction of load-bearing structures. The blocks, initially developed for mortarless structures as a means for reducing construction time and labour costs, also avoided the reduction in bearing capacity associated with lateral expansion of mortar layers.

Despite these benefits, conventional interlocking systems do have some weaknesses. The main drawbacks are the need for different-shaped blocks to satisfy various construction needs and structurally weak points being created by the presence of keys or connectors.

In a bid to improve upon the original interlocking blocks a new type of block has been developed without the need for connectors, grooves or joints, making it more versatile and robust. The new blocks, which utilise the principle of topological interlocking and are known as osteomorphic block, have been shown to increase earthquake resistance due to the ability of the blocks for relative movement, allowing for higher flexibility and energy absorption.

The result is an interlocking system that integrates all construction purposes under one block shape. Possible applications range from buildings and retaining walls, to foundations and pavers, to offshore scour protection mats and shields.

Negative Poisson's ratio and negative stiffness

Rational approach to hybrid materials with internally engineered architecture

Hybrid materials with elements possessing negative Poisson’s ratio or negative stiffness have outstanding functionality not achievable by conventional means - increased effective stiffness, reduced thermal stress and extreme damping.

Further progress in the field requires a proper theoretical basis. The project develops experimentally verified theoretical and computer models capitalising on our success in theoretical prediction and manufacture of new structures with negative Poisson’s ratio, a discovery of negative stiffness in interlocking assemblies and new concepts explaining its mechanism.

Results will be used for developing hybrid materials with internally engineered architecture and explaining behaviour of some natural materials.