Alessandro F. Rotta Loria

The development of approaches that can autonomously fill and heal material voids and yield composites with tailorable properties is increasingly relevant in engineering. Here, we experimentally and numerically investigate the potential of electrodeposition to engineer stainless‐steel lattice scaffolds with variable structures immersed in seawater. Applied voltages of 2–4 V for up to 168 h govern mineral composition, shifting precipitation from Ca‐enriched to Mg‐dominant. Deposits consist primarily of CaCO ₃ and Mg(OH) ₂ polymorphs, with the former accounting for ~21% of the mineral fraction at 2 V and the latter reaching ~92%–94% at 3–4 V. Lattices can gain up to 420 mg of minerals, ~135% of their untreated mass. The mineralization is enhanced at lattice boundaries, corners, and struts by geometry‐dependent electric‐field localization. Mechanically, electrodeposition reduces stress at 8% strain from 53.4 to 34.0 MPa in the small‐opening lattice, which shows a ductile response, while increasing peak stress from 11.7 to 13.5 MPa and residual stress from 4.9 to 10.1 MPa in the large‐opening lattice, which shows a brittle response. Altogether, the results of this work show that electrodeposition enables geometry‐sensitive, autonomous void filling, modification of chemical and mechanical properties, and the potential to grow architected composites with electricity.

This study investigates the potential of phase change materials in planar energy geostructures for enhancing thermal energy storage and mitigating underground climate change. To date, phase change materials have been studied and implemented in many different thermal energy storage applications, including energy geostructures such as energy piles. Only recently have planar geostructures been examined for their energy storage capabilities, and there is no comprehensive work on their behavior when utilizing phase change materials. In this study, three-dimensional hydro-thermal simulations model seasonal underground thermal energy storage operations enhanced with phase change materials to establish an understanding of their behavior in planar underground geometries. The effectiveness of phase change materials for enhancing thermal energy storage capabilities and reducing thermal anomalies is analyzed in two ways. First, multiple geometric configurations of the materials in energy walls are tested and compared to each other and to a configuration with no phase change materials to generalize their potential. Second, the properties are modified to determine their performance under further optimization. Initial findings suggest that an efficiency increase of approximately 30% compared to cases without phase change materials can be achieved with proper design considerations, but the mitigation of underground climate change with the materials is limited. This technology offers promising potential to enhance the storage capabilities of many planar underground surfaces and contribute to a more sustainable, energy-efficient society.

Granular materials are routinely subjected to thermal cycling due to natural and anthropogenic phenomena. Despite the ubiquity of this occurrence and its relevance for science, engineering, and technology, the long‐term thermo‐mechanical response of granular materials to repeated heating and cooling remains poorly understood. In this work, we employ large‐scale discrete element simulations to investigate the evolutionary response of granular materials subjected to cyclic thermal loading, with the aim of understanding whether these materials deform indefinitely upon thermal cycling or undergo particle rearrangement towards a stabilized structural state. By considering the response of such materials under isotropic and laterally restrained (oedometric) conditions, the study explores the influence of temperature amplitude, mean effective stress, initial relative density, and material properties like Young's modulus, interparticle friction coefficient, particle thermal expansion coefficient, and particle size distribution. The simulations show that the consideration of a sufficient number of thermal cycles always brings granular materials to a stabilized structural state through plastic shakedown, regardless of their boundary conditions, stress state, or material properties. This evidence suggests that plastic shakedown is a fundamental mechanism governing thermally induced strains in granular materials subjected to cyclic heating and cooling, in much the same way it happens with cyclic mechanical loading.

Experimental laboratory investigations underlie most of the knowledge about the mechanics of soils under non‐isothermal conditions and their thermally induced deformation. Despite advances, the understanding of thermally induced deformation of soils remains inconsistent, hindering the development of a coherent framework that can advance science and engineering. Considering this challenge, this paper presents an analysis of the established methodology to determine thermally induced soil deformations from laboratory experiments. Established equations are re‐derived, verified, and compared, and the resulting predictions are analyzed. Data support that the quantification of thermally induced soil deformations can be affected by volume corrections and calibrations, the integration of conservation equations under non‐isothermal conditions, the misuse of thermal expansion coefficients, and the lack of repeatability tests and uncertainty quantification. Quantitative analyses support the conclusion that these aspects contribute to the contradictions in the state‐of‐the‐art. Therefore, this work proposes an updated methodology to experimentally quantify the thermally induced deformation of soils, whose widespread adoption is supported by the provision of an open‐source toolbox that implements the proposed changes to the state‐of‐the‐art: The Thermally Induced Deformation Analysis Library, TIDAL.

Coastal erosion poses significant challenges to marine ecosystems and infrastructures worldwide. Conventional mitigation methods, such as concrete barriers and beach nourishment, lack susta...

Granular materials, widespread in natural and engineered systems, are constantly subjected to cyclic temperature variations. Experimental and numerical evidence has demonstrated the existence of ‘terminal states’ in granular materials subjected to cyclic mechanical, hydraulic and chemical loading. In such cases, granular materials deform until reaching a terminal void ratio, after which their density remains unchanged under further cycling. However, the existence of terminal conditions and densities has seemingly never been investigated in relation to thermal cycling. This study addresses this knowledge gap using discrete-element modelling. Specifically, it examines the influence of temperature amplitude and initial relative density on the structural evolution and bulk deformation of granular materials subjected to thermal cycles. The results reveal that thermal cycling can also drive granular materials towards a distinct terminal density. Yet, thermal cycling drives granular materials towards a unique terminal density determined solely by the cyclic temperature amplitude. This behaviour contrasts with cyclic mechanical loading, which leads to different terminal densities depending on the initial void ratio and applied stress amplitude. While the number of thermal cycles required to reach this state is strongly influenced by the initial void ratio, the final terminal state is independent of it.

The subsurface is increasingly exploited to host energy, utilities, and infrastructure systems that interact with surrounding soils and rocks through their thermal and functional operation. Prominent examples are provided by energy geostructures, district heating networks, buried power cables, steam and water pipes, and underground nuclear waste repositories. Many of these systems incorporate cylindrical cavities and operate under varying thermal conditions, thereby influencing the thermo‐mechanical state of the surrounding ground. While advanced numerical simulations have significantly improved understanding of these processes, their complexity and computational cost restrict their use in engineering practice. By contrast, analytical models offer computational efficiency and theoretical rigor, but limited analytical solutions are currently available to address the analysis of cavity‐type systems involving non‐isothermal conditions and interconnected mechanical interactions with the ground. To address this gap, this study introduces an analytical model that extends the classical cavity expansion theory to non‐isothermal conditions. The formulation integrates thermo‐elastic effects under both steady‐state and transient regimes, enabling the prediction of stress, strain, and displacement distributions induced by temperature variations around a cylindrical cavity. Validation against finite element simulations confirms the reliability of the proposed analytical approach across a range of subsurface conditions. The analytical model provides a practical and theoretically robust tool that overcomes the daunting resources required by multiphysical numerical modeling approaches.