Dynamics of micro-trusses

deformed350x200We study the mechanical behaviour of micro lattices (also known as micro-trusses) under a range of loading conditions. Where applicable, we apply homogenisation and continualisation principles to derive higher-order gradient theories with a transparent interpretation of the emerging internal length scales.

Under elastic loading conditions, the emergence of stop bands and wave filters is of interest in the design of materials for insulation purposes. Under post-peak loading conditions, the interest is on designing truss materials with maximum capacity to absorb blast and impact waves.

In order to quantify energy absorption capacity of micro-trusses during blast, impact and ballistic attacks, a series of quasi-static and impact experiments will be performed on micro-truss samples. Additive layer manufacturing techniques where a structure is built up progressively by the selective melting of specific regions in successive layers of metal powder will be used to manufacture these samples with different unit cell geometries in order to maximise the freedom in creation of potentially complex micro-truss structures. Following the experiments, the multi-purpose nonlinear finite element analysis program LS-DYNA will be used to simulate the response mechanisms of micro-trusses. This will allow us to explore further the impact behaviour of micro-trusses and to clarify strain-rate sensitivity of such structures.