Structural Materials Research Articles

Reactive powder concrete beam design using a mathematical software to reduce costs

AbstractReactive powder concrete is widely recognized for its remarkable mechanical characteristics and resilience, rendering it an ideal option for structural uses that include heavy loads. However, the intricate interaction of numerous material and geometric aspects makes constructing reactive powder concrete beams extremely difficult. By using MATLAB to provide an optimized design framework for beams, this research tackles these issues. Particle swarm optimization and evolutionary algorithms are two of the advanced techniques used in the study to solve the optimization problem. It also includes constraints other one as structural requirements and material limitations. Results demonstrate that MATLAB-based optimization facilitates effective design, lowering costs and material consumption, with potential for more applications in the building sector.

The High-Strain-Rate Impacts Behaviors of Bilayer TC4-(GNPs/TC4) Composites with a Hierarchical Microstructure

Ti matrix composites (TMCs) are promising structural materials that meet the increasing demands for light weight the automobile and aircraft industries. However, the room temperature brittleness in the traditionally homogeneous reinforcement distribution of TMCs limits their application in high-strain-rate impact environments. In the present study, novel bilayer TMCs with hierarchical microstructures were designed by the laminated combination of graphene nanoplatelet (GNPs) reinforced TC4 (Ti-6Al-4V) composites (GNPs/TC4) and a monolithic TC4. Meanwhile, the configuration of the microstructure, impact performance V50, and deformation modes of the bilayered TC4-(GNPs/TC4) plate was investigated. The plates were fabricated via field-assisted sintering technology (FAST). It turned out that the TC4-(GNPs/TC4) plate with a 7.5 mm thickness against a 7.62 mm projectile exhibited greater impact performance (V50~825 m/s) compared to the TC4 and GNPs/TC4 single-layer plates. The plate failure modes were dependent on the microstructure while the failure behaviors seemed to be influenced by the hierarchical configuration. This work provided a new strategy for utilizing TMCs in the field of high-strain-rate impact environments.

Hybridizing anomalous Nernst effect in artificially tilted multilayer based on magnetic topological material.

Transverse thermoelectric conversion holds significant potential in addressing complex challenges faced by classical Seebeck/Peltier modules. A promising transverse thermoelectric phenomenon is the anomalous Nernst effect originating from nontrivial band structures in magnetic topological materials. However, the currently reported performance of the anomalous Nernst effect in topological materials, e.g., Co2MnGa, remains insufficient for practical thermoelectric applications. Here, we unveil an unconventional availability of the anomalous Nernst effect by integrating magnetic topological materials into artificially tilted multilayers, known to exhibit the structure-induced transverse thermoelectric conversion due to the off-diagonal Seebeck effect. Our experiments reveal that the transverse thermoelectric performance in Co2MnGa-based artificially tilted multilayers is improved through the hybrid action of the anomalous Nernst and off-diagonal Seebeck effects, with the magnetization-dependent performance modulation being one order of magnitude greater than the performance achievable with the anomalous Nernst effect alone. This synergy underscores the importance of hybrid transverse thermoelectric conversion and paves a way for advancing thermoelectric applications using magnetic materials.

Stretchable and body conformable electronics for emerging wearable therapies

AbstractWearable therapy represents a research frontier where material science, electrical engineering, and medical disciplines intersect, offering significant potential for remote and portable healthcare. Unlike conventional approaches that rely on rigid materials, the ability to stretch is crucial for therapeutic devices to achieve enhanced mechanical adaptability. Moreover, the conformable integration of these devices into the body is pivotal in establishing reliable interfaces for long‐term treatment. These emerging devices provide an attractive platform for developing new therapeutic protocols that do not disrupt daily activities. This review comprehensively overviews recent progress in stretchable and body‐conformable electronics for wearable therapeutic applications. The discussion begins with the design and fabrication of these devices through structural designs and material innovation. The therapeutic mechanisms adopted by these devices are then systematically explored. Furthermore, the article delineates the crucial characteristics of wearable therapeutic devices, such as biocompatibility, secure skin attachment, and effective moisture management. This review article is poised to inspire innovative device designs and treatment protocols for future medical technology.

Bio‐Inspired Bright Non‐Iridescent Structurally Colored Nanopigments Featuring Additive Color Mixing Performance

AbstractOwing to the unique features of high chemical and photostability, structurally colored materials can potentially replace organic dyes and pigments in many applications. The most common fabrication method of structural color materials is the “bottom‐up” self‐assembly approach. However, the assembled structures are easily damaged by external forces, leading to color fading or even disappearance. Therefore, it is still a challenge to fabricate structural colors that mimic the appearance of absorbing pigments without assembly processes. Inspired by the Steller's jay, non‐iridescent structurally colored nanopigments are created, which are composed of hollow SiO2 (H‐SiO2) microspheres with amorphous carbon on the inner wall of the shell and disordered metasurfaces on the shell layer. It is shown that the color originates from the synergistic effect of the disordered metasurfaces and the amorphous carbon layer, which can produce strong coherent scattered light and effectively absorb incoherently scattered light, respectively. Amazingly, the H‐SiO2 microspheres can maintain their structural colors even after grinding or being dispersed in water. What's more, through the additive color mixing of two base colors and precise tuning of their ratios, gradient structural colors that spanning the visible spectrum can be achieved. These features indicate promising prospects for the designed nanopigments.

Investigation of the effect of repeated variable loads on the life cycle of transport structures using polymer composite materials

The problem of the life cycle of transport structures using polymer composite materials (PCM) is touched upon. It is noted that in the life cycle of transport structures, at the stage of operation, the endurance of structural materials plays a key role. The results of experimental studies of PCM depending on the magnitude of the coefficients of reinforcement with fiberglass reinforcement (SPA) are presented. The influence of the degree of prestress of the SPA on the life cycle of the structural element has been established. It is emphasized that in the study of the life cycle of structures, the coefficient of asymmetry of the external load application cycle is of no small importance. As a result of the study, it was found that with an increase in the coefficient of asymmetry of the application of an external load with a simultaneous increase in the prestress in the SPA, the coefficient of endurance, and, consequently, the life cycle of the element, increases.

Flood fragility and vulnerability functions for residential buildings in the Province of Leyte, Philippines

AbstractThe Philippines experiences frequent flooding, but, despite expansive tools for risk reduction, there remain gaps in understanding generalised relationships between flood events and damage to residential structures for regions outside the nation's capital. This gap has limited the ability to model flood risk and damage without robust functions to link hazards and housing vulnerability. This research draws on 394 household surveys to empirically derive a suite of flood fragility and vulnerability functions for residential structures in the Province of Leyte for light material, elevated light material and masonry structures. The results showed that masonry construction was more resilient to floods compared to light material counterparts. Elevated light material structures also exhibited lower damages at low inundations but tend to fail abruptly at flood depths greater than 3 m. By empirically deriving flood damage functions, the findings contribute to a more localised approach to quantifying housing vulnerability and risk that can be used for catastrophe and risk modelling, with applications for government agencies, the insurance industry and disaster risk researchers. This research lays the foundation for future flood risk mapping with growing significance under climate change.

Unveiling Noncentrosymmetric Pyridine Carboxylates from Centrosymmetric Templates through Motif Configuration Modulation in Zero-Dimensional System.

Developing approaches to induce noncentrosymmetric (NCS) frameworks through atomic-scale structural optimizations is crucial due to the growing need for new ultraviolet (UV) nonlinear optical (NLO) materials. Herein, the first two new NCS pyridine carboxylates, ZnBr(C6H3.5FNO2)2 (1) and Cd(C6H3FNO2)2(H2O)2 (2), were successfully synthesized using centrosymmetric (CS) templates and rational structural reconstructions induced by different ionic radius. Both compounds crystallize in the orthorhombic system and feature metal-centered zero-dimensional (0D) isolated clusters. Substituting the [ZnO2N2O] pyramid in the CS pyridine carboxylate with the [ZnO2N2Br] pyramid in compound 1 breaks the centrality, leading to an NCS framework with a second harmonic generation (SHG) response of 1.7 × KH2PO4 (KDP). Introducing a larger Cd2+ cation results in a trans-to-cis transition of the [MO4N2] (M = Zn, Co, and Ni in CS templates, Cd in 2) octahedra, forming a wing-shaped asymmetric 0D cluster with an SHG response of 2.1 × KDP. These findings indicate an approach that can effectively induce NCS structures of 0D organic-inorganic hybrid materials.

The Restoration of New Gourna: Safeguarding the Legacy of Hassan Fathy

Hassan Fathy’s New Gourna project in Egypt (1946-52) is renowned as a pioneering example of sustainable urban settlement, integrating traditional technologies with modern architectural principles and serving as an inspiration to architects and planners worldwide. But decades of neglect have resulted in major structural deterioration and demolitions of the original buildings. In response, a project titled “Safeguarding Hassan Fathy’s Architectural Legacy in New Gourna” has been undertaken through a collaboration between UNESCO and the Egyptian Ministry of Culture, as defined by the National Organization for Urban Harmony (NOUH) for the period 2019-21. This initiative aims to conserve and repurpose the public heritage buildings while addressing the critical issue of groundwater. NOUH has now taken the project into a second phase (2023-24). This paper outlines the symptoms and causes of deterioration in New Gourna Village and reviews the restoration efforts applied to four major buildings: the khan, the mosque, the theater, and Hassan Fathy’s house. Further research will detail the restoration project in each case, including the documentation phase and the specific restoration techniques applied to each structural element and material.

Advances in machine learning methods in copper alloys: a review.

Advanced copper and copper alloys, as significant engineering structural materials, have recently been extensively used in energy, electron, transportation, and aviation domains. Higher requirements urge the emergence of high-performance copper alloys. However, the traditional trial-and-error experimental observations and computational simulation research used to design and develop novel materials are time-consuming and costly. With the accumulation of material research and rapid development of computational ability, the thorough application of material genome engineering has sped up the development of novel materials and facilitates the process of systematic engineering application. This review summarizes the benefits of data-driven machine learning techniques and the state of the art of machine learning research in the area of copper alloys. It also displays the widely used computational simulation approaches (e.g., the first-principles calculation, molecular dynamics simulation, phase-field simulations, and finite element analysis) and their combined applications in material design and property prediction. Finally, the limitations of machine learning research methods are outlined, and future development directions are proposed.

Axial mechanical properties of welded orthogonal trapezoidal aluminum honeycomb as filler material for nuclear equipment impact limiter.

Lightweight porous structural materials have excellent energy absorption performance, and their application are gradually appeared. This paper takes the shock-absorbing material of nuclear equipment transportation casks as the starting point, and manufactures an orthogonal trapezoidal aluminum honeycomb by welding (WOTAH). The mechanical properties with different cell thicknesses and cell size ratios under different impact loads are studied through experimental and simulation methods, and the deformation process and energy absorption performance of the materials are obtained. The energy absorption performance of materials under quasi-static loading was investigated using plastic deformation theory and compared with experimental results. Based on the experimental results, the least squares method was used for data fitting to obtain the C-S dynamic constitutive relationship of the material. The equivalent structure was used to replace the honeycomb structure for simulation, and the influence of strain rate effect and structural size on material properties was further studied. Through the above mechanical performance analysis and comparison with wood, it is shown that WOTHA has feasible for the application of nuclear equipment impact limiter.

Exploring structural variances in monatomic metallic glasses using machine learning and molecular dynamics simulation.

BCC and FCC metals have different glass-forming abilities (GFA) and exhibit different characteristics during the glass transition. However, the structural origin of their different GFAs is still not clear. Here, we explored the structures of eight monatomic metallic glasses by combining molecular dynamics (MD) simulations and machine learning (ML). Our findings reveal that, despite their common long-range disordered atomic structure, metallic glasses can be further classified into two distinct categories indicating an underlying structural order within the disorder. Using machine learning, we found that BCC liquids can sample more diverse glass states than FCC liquids. Furthermore, glasses formed from BCC metals (GFFBs) exhibit a higher degree of disorder than glasses formed from FCC metals (GFFFs). These findings highlight the inherent differences between GFFFs and GFFBs, which help explain the different glass-forming abilities of FCC and BCC metals. Additionally, our results demonstrate the promising potential of computer vision and ML methods in exploring material structures. Classical molecular dynamics simulations were employed to generate configurations of GFFBs and GFFFs, and the simulations were performed using the LAMMPS code. Inter-atomic interactions were described using a classical embedded atom model (EAM) potential. The initial configuration of the model consists of 32,000 atoms in a three-dimensional (3D) cubic box with periodic boundary conditions applied in all three directions. For machine learning, we utilized an unsupervised machine learning method along with MobileNetV2 for classifying glass structures. Image entropy and image distances were used to measure the structural differences of the metallic glasses.

Treatment of Cigarette Butts: Biodegradation of Cellulose Acetate by Rot Fungi and Bacteria

This study demonstrated the biodegradation of two different brands of cigarette butts (CBs), which are primarily composed of cellulose acetate, by four distinct microorganisms. These included the white rot fungus Pleurotus ostreatus, the brown rot fungus Lentinus lepideus, and the bacteria Bacillus cereus and Pseudomonas putida. After 31 days of treatment, weight loss measurements revealed a mass loss of 24–34%, where B. cereus exhibited the greatest efficacy in terms of mass loss for both brands of CBs. Fourier-Transform Infrared Spectroscopy (FTIR), confocal microscopy, and scanning electron microscopy (SEM) confirmed changes in the surface of the CBs, attributable to structural wear and material breakdown, indicating effective biodegradation by the evaluated microorganisms. Furthermore, the analyses confirmed changes in the surface of the CBs, attributable to structural wear and material breakdown, indicating effective biodegradation by the evaluated microorganisms.

Application of natural fibre pultruded profiles in diverse lightweight structures and architectural scenarios

AbstractReevaluating the materials that shape our built environment holds significant importance for sustainable construction. This research introduces newly developed natural fibre pultruded profiles, composed of flax fibres and bio-resin, customised for specific properties and targeted applications. Engineered to withstand both bending and compression loads, these profiles have been subjected to rigorous mechanical testing to demonstrate their compression and flexural strength, as well as flexibility. The emphasis lies on the bottom-up design approach, guiding the creation of applications suitable for this innovative material in various lightweight structures. The paper presents a series of case studies showcasing the use of biocomposite profiles in diverse design and structural contexts. The initial focus was on active-bending structures, highlighting the material’s flexibility, showcased at a ten-metre span structure, the first large-scale demonstrator. However, given the material’s versatile properties, it is suitable for a wide range of other applications. Key case studies discussed include reciprocal, tensegrity and deployable structures, as well as modular planar or space frame systems. These profiles offer a sustainable and versatile alternative to traditional materials and composites, providing innovative and eco-friendly construction solutions while contributing to industry sustainability goals.

NaNH2 as a Nitrogen Source and Base to Synthesize Triarylamines from Aryl Halides Using Pd-Catalyzed C-N Coupling.

Triarylamines (TAAs) are excellent core structures for multifunctional materials. Reversible single-electron oxidation is the key to versatile applications. Synthesizing these from feedstock materials is inevitable. Here, we report the one-pot synthesis of TAAs from aryl halides and inexpensive NaNH2 as a nitrogen source and base (dual role). The Pd/Xantphos catalytic system shows excellent selectivity toward TAAs from aryl bromides without adding organic amines and an additional base. Various para substituents on the aryl ring show good functional group tolerance in the presence of NaNH2, resulting in moderate to excellent yield (20-91%). Even though the meta-substituted aryl bromides give TAA products in moderate to excellent yields (20-81%), the ortho substitution leads to only diarylamine products. TAAs from aryl chlorides can be achieved only by changing the ligand to Xphos. The mechanistic investigation suggests that three sequential C-N cross-coupling reactions give the TAA products in the presence of NaNH2. The photophysical and electrochemical properties of TAAs and corresponding radicals were tunable based on substitution patterns.

Spectroscopy-guided discovery of three-dimensional structures of disordered materials with diffusion models

Abstract Spectroscopy techniques such as x-ray absorption near edge structure (XANES) provide valuable insights into the atomic structures of materials, yet the inverse prediction of precise structures from spectroscopic data remains a formidable challenge. In this study, we introduce a framework that combines generative artificial intelligence models with XANES spectroscopy to predict three-dimensional atomic structures of disordered systems, using amorphous carbon (a-C) as a model system. In this work, we introduce a new framework based on the diffusion model, a recent generative machine learning method, to predict 3D structures of disordered materials from a target property. For demonstration, we apply the model to identify the atomic structures of a-C as a representative material system from the target XANES spectra. We show that conditional generation guided by XANES spectra reproduces key features of the target structures. Furthermore, we show that our model can steer the generative process to tailor atomic arrangements for a specific XANES spectrum. Finally, our generative model exhibits a remarkable scale-agnostic property, thereby enabling generation of realistic, large-scale structures through learning from a small-scale dataset (i.e. with small unit cells). Our work represents a significant stride in bridging the gap between materials characterization and atomic structure determination; in addition, it can be leveraged for materials discovery in exploring various material properties as targeted.

2D-SnS-Embedded Schottky Device with Neurotransmitter-Like Functionality Produced Using Proximity Vapor Transfer Method for Photonic Neurocomputing.

Neuromorphic computing, which involves the creation of artificial synapses capable of mimicking biological brain activity, has intrigued researchers in the field of artificial intelligence (AI). To advance neuromorphic computing, a highly efficient 2D material-based artificial synapse capable of performing logical and arithmetic operations must be developed. However, fabricating large, uniform films or high-quality structures of 2D materials remains challenging because of their multistep and complex fabrication processes. In the present study, to produce large (Ø ≈ 3 in.), uniform, transparent neuromorphic devices, a novel single-step approach called proximity vapor transfer (PVT) that utilizes van der Waals (vdW) materials is employed. This single-step technique, which involves the fabrication of vdW materials on various substrates (glass, ITO, AZO, Mo, and Cu), allows control of the thickness and bandgap tunability. The Schottky device developed via the PVT method using vdW SnS with neurotransmitter (acetylcholine)-like functionality emulates biological synapses and exhibits photoelectronic synaptic behavior with wide-field-of-view synaptic plasticity. In addition, logic gate operations (NOT, OR, AND), reward-cascade neurotransmission, and imaging can be performed using 3 × 3 arrays of the device. This study represents a significant step toward the development of transparent and large-area synaptic devices, which are crucial for advancing AI applications.

The influence of thermally induced cholesteric liquid crystal structural colour for information encryption

ABSTRACT Cholesteric liquid crystal (CLC) is particularly remarkable due to its ability to exhibit structural colour. Structural colour materials offer solutions for information encryption that feature good stability, ease of perceivability, and arbitrary patterns. This work investigates the temperature-dependent variation of CLC structural colour and provides a quantitative analysis of the pitch and helix twist power (HTP) at different temperatures, further exploring its potential applications in information encryption. By recording quick response (QR) code patterns in the LC Polymer of the LC cell, single-pattern and dual-pattern LC cells are prepared, and their applications in information encryption are demonstrated. The QR pattern will be hidden or revealed as the temperature changes by CLC in the LC cell. Additionally, dual-pattern encryption requires polarisers to address the crosstalk issue under white light, making the LC cell a safer solution for access control systems. These results lay a theoretical foundation in CLC stimulus-responsive structural colours and offer valuable insights in information security and anti-counterfeiting applications.

Innovative Applications of Parametric Design and Digital Tools in Architecture: Exploring the Integration of Generative Design and BIM Technology

Abstract. Through parametric design and generative design, as well as the broader Building Information Modeling (BIM) approach, there is now a whole body of new tools being used by architects to are opening up new ways of designing buildings in innovative, efficient and sustainably responsible ways. This paper presents the emergence of parametric design and its evolution from simple structural optimisations to complex fulling the design of complete buildings and entire urban areas. The paper discusses the integration of both parametric design and generative design with Building Information Modelling (BIM). This technology pairing enables architects to research and test hundreds of design alternatives and optimise for particular variables, such as structural integrity, material efficiency and energy use. This paper showcases a number of case studies of how these technologies are applied to develop innovative and sustainable urban environments (eg, Sidewalk Toronto) and discusses the challenges associated with adopting these technologies, such as computational requirements and a lack of digital interoperability between these technologies. The paper concludes by identifying the innovation opportunities for sustainable development and the future of architectural practice that these technologies are offering.

Method to improve the bonding strength of polyethylene terephthalate core with glass fiber reinforced skins in a sandwich composite

AbstractComposite materials provide an alternative to conventional structural materials. Sandwich composites show high bending strength and superior strength‐to‐weight ratio. The major drawback in sandwich composites is debonding of skin from core, that causes failure of a component during the usage at different loads. To overcome this issue, the current work identifies a solution of introducing nylon screws (M6 × 32) to adhere firmly the skins consisting of glass fibers with PET (Polyethylene Terephthalate) core. The sandwich composites were fabricated by vacuum infusion process. Two flat sandwich composites were fabricated; one with nylon screws placed perpendicular to the skin and the other a plain sandwich composite. Mechanical characteristics of the specimens such as fracture toughness, flexural strength and shear strength were studied. Specimens with nylon screws showed 21.78% more fracture toughness compared to plain specimen. The presence of screws acts as hindrance to the propagation of cracks in the interfacial region resulting in the enhancement of debonding resistance of the specimens. Also, sandwich specimens with nylon screws exhibited 136% and 142% improvement in flexural and shear strength respectively when compared to plain sandwich specimens. The investigation of scanning electron microscope (SEM) images of tested specimens indicates strong interfacial bonding between skin and the core of specimens with nylon screws.Highlights Introduction of light‐weight nylon screws in z‐direction enhanced the bonding between face sheets and foam core. Sandwich composites with nylon screws exhibited superior bending and shear strength compared to plain specimens. Crack propagation in the interfacial region is restricted by the presence of nylon screws. Investigation of fractured specimens indicated a strong interfacial bonding in the specimens with screws.