#InverseFE #MaterialTesting #Plasticity #AdditiveManufacturing

Lattice structures are complex geometries that are often difficult to characterise or model explicitly. This is becoming even more difficult in applications where failure is expected to occur as for example when these structures are used to dissipate energy as a protection or impact mitigation device. Our client from the additive manufacturing industry approached us to determine the material behaviour of aluminium alloy metal sandwiches when stressed beyond their yield limit for an aerospace application.

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Using a combination of low to high-rate 4 point bending tests and FE modelling, we were able to fully characterise and derive the material properties of the lattice structure, solid panel, and transition zone in a lattice sandwich panel used in aerospace components.

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Using Digital Image Correlation (DIC) and our internally developed fully automated inverse FE modelling algorithm we were able to efficiently analyse the failure modes of the samples. We also develop a bulk material formulation to represent the behaviour of different alloys and lattice structures when plastically deformed, including the effect of self-contact.