Macro-mechanical Behavior Research Articles

Effect of Particle Shape on Cyclic Shear Behavior of Granular Mixtures–Geogrid Interface

The cyclic shear stiffness and damping ratio of angular and round particle geogrid interfaces is of much concern in reinforcement structure seismic analysis. In this study, various component percentages of crushed limestone and spherical granular medium mixtures were used to investigate the role of particle regularity in static and cyclic direct shear tests. The test results revealed that an increase in the proportion of round particles decreased cyclic shear strength and volume change. The phenomenon of shear softening was observed with a high amplitude of shear displacement when the proportion of round particles was increased in the mixture. As the percentage of round particles increased, the maximum interface shear stiffness decreased significantly from, 39.69 to 28.28 MPa/m, but a reverse trend in the maximum damping ratio was observed, from 0.308 to 0.37. The effect of cyclic shear history and proportion of round particles on interface strength parameters was also analyzed. A linear regression model was fitted to the data for quantifying the relationship between the proportion of round particles and friction angle. The results suggest that different percentages of round and angular particles can produce varying degrees of particle interlock between aggregate and geogrid, influencing the macro-mechanical behavior of the reinforced soil interface.

Interparticle friction behaviors of kaolinite: Insights into macroscale friction from nanoscale

The friction behavior of widespread clay minerals is a major concern in many geo-engineering problems, such as the stability of soft soil foundations and the induction of seismic fault zones. The present work aimed to study the friction behaviors of kaolinite at the particle level using the molecular dynamics method. The effects of normal force (Fn), shear velocity (v), and interfacial water film on nanofriction were discussed. The “stick-slip” phenomenon and periodic evolution of friction forces (Ff) were observed in dry friction and became less pronounced with water lubrication. The dry Ff of kaolinite was found to be insensitive to Fn. However, wet Ff exhibited a linear increase with Fn and then transitioned to a non-linear relationship as slip displacement increases due to the continuous loss of water molecules from the interface during friction. Notably, at high loads (Fn ≥ 30 nN), the peak friction of wet kaolinite showed characteristics similar to dry friction. A velocity-strengthening behavior of kaolinite at high velocities was observed in both dry and wet conditions. The macroscale friction coefficients of kaolinite were predicted from nanofriction data and results showed good agreement with experimental values. This study lays the foundation for bridging micro- and macro-mechanical behaviors, suggesting a new pathway for acquiring precise macroscopic friction of minerals through cross-scale studies.

Study on the macro-mechanical behavior and micro-structure evolution law of broken rock mass under triaxial compression

Study on the macro-mechanical behavior and micro-structure evolution law of broken rock mass under triaxial compression

Quantifying the influence of single particle shape on crushing characteristics of recycled aggregates: Experimental and numerical insights

Exploring the interplay between shapes and crushing characteristics of recycled aggregates (RA) is pivotal for understanding their macro-mechanical behavior in bulk materials. This investigation quantitatively characterizes the shapes of recycled bricks (RB), recycled concrete (RC), and recycled mortar (RM) particles, and assesses their single-particle crushing characteristic. Key focus areas include the analysis of crushing modes, fractal attributes, strength, and energy, supplemented by a comparative study using discrete element method (DEM) simulations to predict outcomes for particles of specific sphericity. Findings reveal that the shapes of RA particles are mainly disk, block, blade and bar, with particle size showing negligible influence on these forms. Crushing behaviors are categorized into penetrating fracture, corner rupture, and overall fragmentation, closely linked to particle sphericity. Notably, an increase in sphericity leads to a reduction in fractal characteristics of RA, refining the gradation distribution from broad to narrow spectrums. An exponential relationship is identified between the crushing strength of RA and particle sphericity, a pattern also mirrored in the correlation between crushing energy and sphericity, thereby underscoring the significant influence of particle shape. These relationships facilitate predictions regarding the crushing strength and energy based on sphericity. While numerical simulations broadly align with experimental data, discrepancies in the crushing energy of highly spheric particles necessitate adjustments, resulting in a modified predictive equation for crushing energy. This work enriches the understanding of RA crushing behavior, offering invaluable insights for predicting the single-particle strength and deformation characteristics across different sphericities, thus advancing material engineering and recycling practices.

Macro-micro mechanical behavior of saturated cemented sands during drained triaxial shearing

To enhance the understanding of the macro-micro mechanical behavior of cemented sands, a series of drained triaxial shearing tests were conducted on saturated cemented sands with varying cement contents and confining stresses. These tests incorporated high-performance acoustic emission (AE) monitoring and an environmental scanning electron microscope (ESEM) technique. The results yielded quantitative interpretations of macro-mechanical response, microstructural variation, and AE behaviors. Specifically, increasing cement content led to an exponential reduction in porosity (or pore area ratio) and a power increase in pore number, possibly due to the production of hydration products that segment large pores. Relationships were established among peak strength (or AE hits), cement content, and confining stress. However, AE trends diverged from those observed in peak strength due to microstructural modifications under different cement contents and their resulting differences in micromechanical behavior during shearing. General relationships between AE rate and mechanical parameters were established during the initial shearing stage, regardless of cement content and confining stress. Moreover, AE evolution efficiently characterized subtle variations in failure patterns due to its high sensitivity to failure-induced structural modifications. These contributions have the potential to establish a non-destructive field evaluation framework and provide guidelines for the efficient utilization of cemented soils in geological and geotechnical engineering applications.

Micro-zone and macro mechanical behavior of SiCf/Si3N4 composite modified by intra-bundle matrix

In this work, the microstructure of the interfacial zone was optimized to improve the mechanical properties of SiCf/Si3N4 composite, and the relationship between micro-zone and macro mechanical behavior was revealed. For SiCf/Si3N4, the interphase destruction occurred during the Si3N4 deposition process, leading to the existence of discontinuous interphase in the outside of intra-bundle area. After incorporating SiBCN and SiC matrices into the fiber bundle, the BN interphase can be well protected, and the uniformity of the matrix microstructure within the fiber bundle was further enhanced, which increased the Weibull modulus of the interfacial shear strength (IFSS), resulting in the higher load sharing efficiency in fiber bundle and the enhanced macro-mechanical properties. Especially after incorporating SiC matrix into intra-bundle area, the higher IFSS also can be obtained, corresponding to the higher load transferring efficiency, and the strength and toughness of the composites were improved significantly.

Investigation of three-dimensional model reconstruction and fractal characteristics of crack propagation in jointed sandstone

The presence of random joints, cracks, and other defects significantly affects the meso-damage mechanism and macro-mechanical behavior of the rock. This study employed micro-CT scanning, digital image processing (DIP), and the rock failure process analysis system (RFPA3D) to reconstruct a genuine mesostructure, creating a three-dimensional (3D) numerical model of jointed sandstone. Under uniaxial stress, this model facilitated the meso-damage evolution process of prefabricated cracks in sandstone with varying dip angles. Additionally, the influence of jointed sandstone heterogeneity and prefabricated cracks with various dip angles on its failure mode and meso-damage mechanical properties were investigated. Utilizing the MATLAB platform, a 3D box dimension algorithm was developed to analyze the fractal characteristics of the mesodamage evolution in the sample. This algorithm enabled the quantitative characterization of the meso-damage evolution of sandstone. This study categorized three types of sandstone final failure modes: composite shear failure, shear failure along the joint surface, and tensile failure. Additionally, linear variations in the elastic modulus and compressive strength of the jointed sandstone were observed with increasing prefabricated fracture inclination, highlighting significant anisotropy. The presence of joints was found to induce and control the failure mode of sandstone. The meso-damage evolution process of sandstone was described in terms of the fractal dimension, indicating that more severe damage corresponded to a larger fractal dimension. This approach offers a novel statistical method for studying the progression of rock damage.

Discrete element simulation study on effects of grain preferred orientation on micro-cracking and macro-mechanical behavior of crystalline rocks

Abstract Grain-preferred orientation significantly influences the brittle fracture mechanism and failure mode of crystalline rocks. However, current grain-based models (GBMs) based on particle flow code (PFC) software are mostly proposed on the basis of the Voronoi tessellation method for grain boundary generation, which is difficult to simulate the heterogeneity of microstructure such as shape and orientation of rock minerals. To study the effect of grain-preferred orientation on macroscopic mechanical properties and microscopic characteristics of crystalline rocks, a novel grain-based microstructure transformation method (MTM) is proposed. Based on the MTM, a GBM with a target aspect ratio and crystal orientation is obtained by transforming the Voronoi crystal geometry through a planar coordinate mapping. Specifically, embedded FISH language is used to control random mineral seed size and distribution pattern to generate Tyson polygons. A polygon geometry that satisfies the rock texture is obtained as a grain boundary by spatially transforming the vertex of the Tyson polygon. The transformed complex geometry is taken as the crystal structure of the GBM, and the Lac du Bonnet granite models with different aspect ratios and crystal orientations were developed in PFC2D. Finally, a series of unconfined compressive strength tests are performed in PFC2D to verify the proposed modeling methods for the geometric variation of the crystals and to study the effects of the preferred orientation of the grains on the macroscopic mechanical properties and microscopic fracture mechanisms of the crystalline rocks from different perspectives.

Deciphering Hydrogen Embrittlement Mechanisms in Ti6Al4V Alloy: Role of Solute Hydrogen and Hydride Phase.

Ti6Al4V (Ti64) is a versatile material, finding applications in a wide range of industries due to its unique properties. However, hydrogen embrittlement (HE) poses a challenge in hydrogen-rich environments, leading to a notable reduction in strength and ductility. This study investigates the complex interplay of solute hydrogen (SH) and hydride phase (HP) formation in Ti64 by employing two different current densities during the charging process. Nanoindentation measurements reveal distinct micro-mechanical behavior in base metal, SH, and HP, providing crucial insights into HE mechanisms affecting macro-mechanical behavior. The fractography and microstructural analysis elucidate the role of SH and HP in hydrogen-assisted cracking behaviors. The presence of SH heightens intergranular cracking tendencies. In contrast, the increased volume of HP provides sites for crack initiation and propagation, resulting in a two-layer brittle fracture pattern. The current study contributes to a comprehensive understanding of HE in Ti6Al4V, essential for developing hydrogen-resistant materials.

Response Mechanism of the Residual Strength to the Mesostructure of the Shear Surface in the Gravelly Slip Zone of Ancient Landslides

AbstractAncient landslides tend to reactivate along pre‐existing slip zones that have reached a residual state. On the eastern margin of the Tibetan Plateau, previous research has indicated that the slip zone of ancient landslides is primarily composed of clayey soil with gravel, known as gravelly slip zone soil. However, the relationship between the macromechanical behavior of gravelly slip zones and the mesostructure of the shear surfaces affected by gravel is still unclear. Herein, ring shear tests and reversal direct shear tests were performed on gravelly slip zone soil, and the 3D morphology and shear surface roughness were quantitatively characterized by using 3D laser scanning technology and the power spectral density method. The results showed a significant correlation between the friction coefficient of the shear surface and its roughness. Gravel played a crucial role in influencing the macromechanical behavior of slip zones by altering the mesomorphology of the shear surfaces. By analyzing the mechanical properties of the contact unit on the shear surface, the residual strength of the gravelly slip zone was found to be jointly controlled by the basic strength of the fine‐grained soil and the undulations caused by the gravel. Finally, a residual strength model was developed for the gravelly slip zone considering both the strength of the fine‐grained soil and the shear surface roughness caused by the gravel.

Micro-dissolution mechanism and macro-mechanical behavior of red-bed soft rock under dry-wet cycle

The microscopic pore characteristics of rocks have an important influence on their macroscopic mechanical behavior. The micro-pore dissolution mechanism of red-bed soft rock was revealed by the dry-wet cycle method, and its macroscopic mechanical behavior was studied by a series of uniaxial compression tests. The results show that with an increase in the number of dry-wet cycles, the micro-pore dissolution and micro-grain spalling of red-bed soft rock result in its porosity increasing nonlinearly. Under the action of the axial load, the number of micro-fractures increases and evolves from tensile fracture to shear fracture, and the macroscopic failure mode changes from brittle splitting failure to ductile conical failure.

Simulation of a Composite with a Polyhydroxybutyrate (PHB) Matrix Reinforced with Cylindrical Inclusions: Prediction of Mechanical Properties.

Biocomposite development, as a sustainable alternative to fossil-derived materials with diverse industrial applications, requires expediting the design process and reducing production costs. Simulation methods offer a solution to these challenges. The main aspects to consider in simulating composite materials successfully include accurately representing microstructure geometry, carefully selecting mesh elements, establishing appropriate boundary conditions representing system forces, utilizing an efficient numerical method to accelerate simulations, and incorporating statistical tools like experimental designs and re-regression models. This study proposes a comprehensive methodology encompassing these aspects. We present the simulation using a numerical homogenization technique based on FEM to analyze the mechanical behavior of a composite material of a polyhydroxybutyrate (PHB) biodegradable matrix reinforced with cylindrical inclusions of flax and kenab. Here, the representative volume element (RVE) considered the geometry, and the numerical homogenization method (NHM) calculated the macro-mechanical behavior of composites. The results were validated using the asymptotic homogenization method (AHM) and experimental data, with error estimations of 0.0019% and 7%, respectively. This model is valuable for predicting longitudinal and transverse elastic moduli, shear modulus, and Poisson's coefficient, emphasizing its significance in composite materials research.

Neural Metamaterial Networks for Nonlinear Material Design

Nonlinear metamaterials with tailored mechanical properties have applications in engineering, medicine, robotics, and beyond. While modeling their macromechanical behavior is challenging in itself, finding structure parameters that lead to ideal approximation of high-level performance goals is a challenging task. In this work, we propose Neural Metamaterial Networks (NMN)---smooth neural representations that encode the nonlinear mechanics of entire metamaterial families. Given structure parameters as input, NMN return continuously differentiable strain energy density functions, thus guaranteeing conservative forces by construction. Though trained on simulation data, NMN do not inherit the discontinuities resulting from topo-logical changes in finite element meshes. They instead provide a smooth map from parameter to performance space that is fully differentiable and thus well-suited for gradient-based optimization. On this basis, we formulate inverse material design as a nonlinear programming problem that leverages neural networks for both objective functions and constraints. We use this approach to automatically design materials with desired strain-stress curves, prescribed directional stiffness and Poisson ratio profiles. We furthermore conduct ablation studies on network nonlinearities and show the advantages of our approach compared to native-scale optimization.

Calibrating polypropylene particle model parameters with upscaling and repose surface method

The discrete element method (DEM) is a computational technique extensively utilized for simulating particles on a large scale, specifically focusing on granular materials. Nonetheless, its implementation requires a substantial amount of computational power and accurate material properties. Consequently, this study delves into an alternative approach referred to as volume-based scaled-up modeling, aiming to simulate polypropylene particles using DEM while mitigating the computational burden and regenerating new material properties. This novel method aims to reduce the CPU time required for the simulation process and represent both the macro mechanical behavior and micro material properties of polypropylene particles. To accomplish this, the dimensions of the polypropylene particles in the DEM simulation were magnified by a factor of two compared to the original size of the prolate spheroid particles. In order to determine the virtual micro material properties of the polypropylene particles, a calibration method incorporating the design of experiments (DOE) and repose surface methodology was employed. The predicted bulk angle of repose (AOR) derived from the upscaled DEM parameters exhibited a remarkably close agreement with the empirical AOR test, demonstrating a small relative error of merely 1.69 %. Moreover, the CPU time required for the upscaled particle model proved to be less than 71 % of that necessary for the actual-scale model of polypropylene particles. These compelling results confirm the effectiveness of enlarging the particle volume used to calibrate micro-material properties in the Discrete Element Method (DEM) through the DOE technique. This approach proves to be a reliable and efficient method

Pressure- and time-dependent alveolar recruitment/derecruitment in a spatially resolved patient-specific computational model for injured human lungs.

We present a novel computational model for the dynamics of alveolar recruitment/derecruitment (RD), which reproduces the underlying characteristics typically observed in injured lungs. The basic idea is a pressure- and time-dependent variation of the stress-free reference volume in reduced dimensional viscoelastic elements representing the acinar tissue. We choose a variable reference volume triggered by critical opening and closing pressures in a time-dependent manner from a straightforward mechanical point of view. In the case of (partially and progressively) collapsing alveolar structures, the volume available for expansion during breathing reduces and vice versa, eventually enabling consideration of alveolar collapse and reopening in our model. We further introduce a method for patient-specific determination of the underlying critical parameters of the new alveolar RD dynamics when integrated into the tissue elements, referred to as terminal units, of a spatially resolved physics-based lung model that simulates the human respiratory system in an anatomically correct manner. Relevant patient-specific parameters of the terminal units are herein determined based on medical image data and the macromechanical behavior of the lung during artificial ventilation. We test the whole modeling approach for a real-life scenario by applying it to the clinical data of a mechanically ventilated patient. The generated lung model is capable of reproducing clinical measurements such as tidal volume and pleural pressure during various ventilation maneuvers. We conclude that this new model is an important step toward personalized treatment of ARDS patients by considering potentially harmful mechanisms-such as cyclic RD and overdistension-and might help in the development of relevant protective ventilation strategies to reduce ventilator-induced lung injury (VILI).

Multiscale modeling and simulation on mechanical behavior of fiber reinforced concrete

A multiscale mechanical model is proposed to quantitatively describe the macro-mechanical behavior of fiber reinforced concrete (FRC) based on its multiscale material compositions. Firstly, according to the actual scale characteristics of compositions, the model of composite material at each scale of FRC, including hardened cement paste, cement mortar and meso-FRC, was geometrically reconstructed; Secondly, the equations of stiffness and strength of composite material at each scale were established by using the equivalent inclusion theory and Ottosen failure criterion, and a multiscale mechanical model of FRC was proposed by upscaling from stiffness and strength of microstructure to macro-mechanical behavior of FRC; Finally, after verified by the experimental results in the literature, the proposed model was used to numerically investigate the loading-induced stress response and the evolution of macro-mechanical properties of FRC in its curing process, as well as the influence of steel fiber parameters, such as volume fraction, aspect ratio and spatial orientation, on the mechanical properties of FRC.

Phase field modeling of freezing characteristics of saturated soil with different particle sizes

The unfrozen water content and its distribution are of importance to the macro mechanical behaviors of frozen soil. In this study, the phase field method was used to deeply investigate and model the evolution of the microstructure of different saturated soils during the freezing process. Particle size distribution and freezing point depression were considered in the simulation of freezing of the soil. The soil freezing characteristic curves of the soil with different particle sizes were well predicted by the phase field method. Moreover, the unidirectional freezing test was used to validate the proposed method. The simulation results successfully predicted the inhibition effect of soil particles on the spread of pore ice during the cooling process. A series of mesoscale characteristics can be well simulated, such as unfrozen water film, retardation effect of soil particles, nonhomogeneous freezing front, and isolated ice and unfrozen water. Our results provide a deeper insight into the freezing process of porous media, including the formation of pore ice, and the movement of the freezing front on a mesoscale.

Simulation of the deformable lateral boundaries in biaxial test using DEM

Applying the discrete element method (DEM) in soil mechanics can provide abundant information at the particle-scale and facilitates illustration of the macro-mechanical behaviour of soils based on the inter-particle mechanisms. The triaxial test is one of the most common laboratory methods to study the macro-mechanical behaviour of particulate materials such as soil. However, many problems in geotechnical design can be assumed and simplified as a plane strain phenomenon. Therefore a biaxial test can be conducted to reproduce the macro-mechanical behaviour of soil, where the sample is enclosed by two horizontal rigid platens and a vertical latex membrane, which is a deformable continuous element and allows the enclosed specimen to deform freely while maintaining confining stress during loading. This paper presents an algorithm to represent physical and mechanical characteristics of latex membrane in the 2D DEM simulation of biaxial test using the PFC2D code. To investigate the impact of the lateral boundary conditions on the micro-macro mechanical behaviours of soil samples, two sets of DEM biaxial tests are conducted, i.e. with rigid and deformable lateral boundary conditions. The DEM modeling results indicate that the lateral boundary conditions have a significant effect on the micro-scale fabric properties, thickness and inclination of the shear band. The comparison between these two simulations also demonstrates that the lateral boundary conditions play a major role in the peak and post-peak stress-strain behaviours as well as the dilation and critical state behaviours of granular soils.

Study of the damage and cracking of heterogeneous rocks based on the FFT method - A comparison of computer generation and image reconstruction models

Studying the influence of microstructure on the damage and cracking process of rocks is of great practical engineering importance for evaluating the mechanical properties of surrounding rocks in complex geological engineering environments. To incorporate rock microstructures into numerical models, two main methods, i.e. computer generation methods (e.g. molecular dynamics, MD) and image reconstruction methods (e.g. digital image processing, DIP), are frequently adopted. However, the strengths and weaknesses, the differences and applicability regarding the two major methods have not been systematically discussed and analyzed in simulating the damage and cracking in heterogeneous rocks. In this study, the MD model was firstly optimized based on the previous work, and the “Realistic grain size based microstructure model generation program” was developed by the observed mineral grain sizes from microscopic images. The DIP model was developed by directly using digital images of rock materials via the image reconstruction methods. On this basis, the damage and cracking process of rocks was investigated and compared with the above two models using a technique based on the Fast Fourier transforms (FFT). To this end, a series of macro and micro experiments were conducted to obtain the basic mechanical properties of the Dingziwan Granite (DG) and several examples are generated by the MD and DIP model with calibrated macro and micro parameters by the laboratory data. The two models combined with the FFT method are applied to predict the macro and micro mechanical behavior of the DG under different confining pressures and their differences and applicability are quantitatively analyzed and compared. The results indicate that, in general, the two models are both capable of predicting the macro and micro mechanical behaviors of the heterogeneous rocks, but each has its own strength. The improved MD model can efficiently study the influence of the rock heterogeneity on its macroscopic behavior, while the DIP model can highly reproduce the microcracking process such as intragranular, transgranular and grain boundary cracking.

Understanding the Expansion and Electrochemistry of Nickel-Rich NMC - Graphite Full Cells Using in-Situ Dilatometry

The higher energy density and lower cost of Ni-rich lithium nickel manganese cobalt (NMC) have made them one of the best cathode materials for Li-Ion batteries (LIBs). Understanding the mechanical behaviour, particularly the volume changes during charging and discharging, is important for the cell design. So far, this has mainly been studied using X-ray diffraction (XRD), which is powerful in understanding the nanoscale crystal level of the material volume change. However, recent papers have shown that XRD is insufficient to capture macroscopic cell expansion [1]. It is also getting more important to consider the synergistic effect of cathodes and anodes in the context of full cells. It is therefore valuable to have in-situ dilatometry filling the gap and unravelling how nano and macro electrochemical and mechanical behaviour differs.Here, we coupled electrochemical analysis with in-situ electrochemical dilatometry to observe macroscopic dimensional changes of NMC811−graphite full cells during galvanostatic cycling under different pressure conditions, voltages, and cathode particle morphologies. Our setup uses a non-contact dilation sensor and independent control over the stack pressure to achieve highly accurate measurements of the electrode expansion, with a linearity of ≤ ±90 nm, resolution of ≤ 0.5 nm, and a drift of ≤ 100 nm/month.The initial investigations of graphite v.s. NMC811 pouch cells (220 mAh) have offered clear evidence of the strong correlation between dilation and electrochemistry, where reversible dilation features in every charge-discharge cycle can be assigned to cathode and anode phase transitions. In addition, our system can effectively isolate the reversible thickness change from the irreversible thickness change known to be potentially correlated to solid electrolyte interphase (SEI),[2] particle rearrangement,[3] and electrode delamination.[4] With different experimental conditions (C-rates, pressure and voltage windows), the full cells demonstrated different electrochemical performances alongside varied dilation behaviours. The observed in-situ dimensional changes improve our understanding of the physical and chemical processes happening while cycling NMC-Graphite full cells.[1] F. B. Spingler, S. Kücher, R. Phillips, E. Moyassari, and A. Jossen, “Electrochemically Stable In Situ Dilatometry of NMC, NCA and Graphite Electrodes for Lithium-Ion Cells Compared to XRD Measurements,” J. Electrochem. Soc., vol. 168, no. 4, p. 040515, 2021, doi: 10.1149/1945-7111/abf262.[2] A. J. Louli, L. D. Ellis, and J. R. Dahn, “Operando Pressure Measurements Reveal Solid Electrolyte Interphase Growth to Rank Li-Ion Cell Performance,” Joule, vol. 3, no. 3, pp. 745–761, 2019, doi: 10.1016/j.joule.2018.12.009.[3] D. Y. W. Yu, M. Zhao, and H. E. Hoster, “Suppressing Vertical Displacement of Lithiated Silicon Particles in High Volumetric Capacity Battery Electrodes,” ChemElectroChem, vol. 2, no. 8, pp. 1090–1095, 2015, doi: 10.1002/celc.201500133.[4] H. Michael et al., “A Dilatometric Study of Graphite Electrodes during Cycling with X-ray Computed Tomography,” J. Electrochem. Soc., vol. 168, no. 1, p. 010507, 2021, doi: 10.1149/1945-7111/abd648.