Porous volumetric solar receivers, used in concentrating solar power plants, are subjected to severe thermal loading, reaching temperature up to 1500°C for SiC materials. Under these conditions, fracture mechanism triggered by heat loading can be often difficult to interpret and analyze. In the literature the thermal effect is often treated as a quasi-static, assuming that crack initiation and propagation occursufficiently slowly [1]. However, depending on the intensity of the thermal shock, the load can induce material instabilities, resulting in rapid crack propagation or even multiple crack branching. Such observations are inherently associated with transient phenomena [2]. In this work, a numerical framework is proposed to simulate the fracture behaviour of a lattice material under thermal loading. A phase-field damage approach coupled with thermal effects is implemented and applied to an optimized porous geometry provided by an external code generator. To account for dynamic responses, the mechanical behaviour is governed by an elastodynamic equation. Thermal stresses arising from temperature variations are included in the stress formulation. The damage evolution is described by a hyperbolic partial differential equation. A major advantage of this approach is that it allows the coupled damage thermo-mechanical problem to be discretized using a fully explicit time integration scheme, whereas a elliptic damage formulation requireS implicit resolution strategies involving the resolution of llarge linear systems of equations. For large-scale problems involving billions of degrees of freedom, the use of fully explicit schemes improves computational efficiency making the proposed formulation particularly well suited for high performance computing applications [3]. A preliminary study focuses on the thermo-mechanical problem to assess thermal effects on a complex porous structure, followed by damage coupling to highlight critical regions prone to failure. REFERENCES [1] B. Bourdin, J-J. Marigo, C. Maurini, P. Sicsic Morphogenesis and Propagation of Complex Cracks Induced by Thermal Shocks, Phys. Rev. Lett., Vol. 112, pp. 014301, 2014. [2] H. D. Bui, A. Ehrlacher et Q. S. Nguyen Propagation de fissure en thermoélasticité dynamique, Journal de Mécanique, Vol. 19(4), pp. 697-723, 1980. [3] L. Mersel, P. Bouda, J. Germain and J.Réthoré, Dynamic damage modelling through phase-field approaches: Assessment, critical analysis and comparison, Comptes Rendus.