Constitutive Modelling and Structural Optimization 

Constitutive Modelling 

Mechanical metamaterials, such as kirigami patterns or micro-trusses, often - but not always - feature a periodic arrangement of geometric constituents, which, along with the base material properties, governs the macroscopic response of a metamaterial subject to a mechanical, temperature, magnetic or other physical field. We developed several multiscale models that can capture the effective physics and mechanics of mechanical metamaterials under large strain undergoing strong geometric and material non linearity as well as predictive models capable of capturing their thermal expansion, energy absorption, and others, such as electrical conductivity, wave propagation, and diffusivity. 

Topology Optimization

We leverage our constitutive models to tackle problems of Topology Optimization for mechanical metamaterials with ideal and as-manufactured defects. Some of our most recent formulations account for geometric and material defects emerging during the process of additive manufacturing and can generate optimized architectures with properties that reflect their as-manufactured counterparts. We also harnessed our modeling and optimization frameworks to develop structurally optimized technology for various sectors, such as orthopedic implants. 

Some Related Publications

Gavazzoni M, Foletti S, Pasini D, Cyclic response of 3D printed metamaterials with soft cellular architecture: the interplay between as-built defects, material and geometric non-linearity, Journal of the Mechanics and Physics of Solids, Vol 58, 104688, 2022. (PDF)

Moussa A, Melancon D, El Elmi A, Pasini D, Topology optimization of imperfect lattice materials built with process-induced defects via Powder Bed Fusion, Additive Manufacturing, Vol 37, 101608, 2021. (PDF)

Xu H, Farag A, Pasini D, Routes to program thermal expansion in three-dimensional lattice metamaterials built from tetrahedral building blocks, Journal of the Mechanics and Physics of Solids, Vol 117, 2018. (PDF)

Xu H, Farag A, Pasini D, Multilevel hierarchy in bi-material lattices with high specific stiffness and unbounded thermal expansion, Acta Materialia, Vol 134, 2017. (PDF)

Liu L, Kamm P, Garc­a-Moreno F, Banhart J, Pasini D, Elastic and failure response of imperfect three-dimensional metallic lattices: the role of geometric defects induced by Selective Laser Melting, Journal of the Mechanics and Physics of Solids, Vol 107, pp. 160-184, 2017. (PDF)

Vigliotti A, Deshpande VS, Pasini D, Non linear constitutive models for lattice materials, Journal of the Mechanics and Physics of Solids 64: 44-60, 2014. (PDF)