Structural Design Research Articles

Using In situ Transmission Electron Microscopy to Study Strong Metal-Support Interactions in Heterogeneous Catalysis.

Precisely controlling the microstructure of supported metal catalysts and regulating metal-support interactions at the atomic level are essential for achieving highly efficient heterogeneous catalysts. Strong metal-support interaction (SMSI) not only stabilizes metal nanoparticles and improves their resistance to sintering but also modulates the electrical interaction between metal species and the support, optimizing the catalytic activity and selectivity. Therefore, understating the formation mechanism of SMSI and its dynamic evolution during the chemical reaction at the atomic scale is crucial for guiding the structural design and performance optimization of supported metal catalysts. Recent advancements in in situ transmission electron microscopy (TEM) have shed new light on these complex phenomena, providing deeper insights into the SMSI dynamics. Here, the research progress of in situ TEM investigation on SMSI in heterogeneous catalysis is systematically reviewed, focusing on the formation dynamics, structural evolution during the catalytic reactions, and regulation methods of SMSI. The significant advantages of in situ TEM technologies for SMSI research are also highlighted. Moreover, the challenges and probable development paths of in situ TEM studies on the SMSI are also provided.

Addressing VAWT Aerodynamic Challenges as the Key to Unlocking Their Potential in the Wind Energy Sector

While the wind turbine industry has been primarily dominated by horizontal-axis wind turbines, the forefront of knowledge of these turbines has revealed significant challenges in various aspects, including manufacturing, structural design, cost, and maintenance. On the other hand, the advantages associated with Darrieus vertical-axis wind turbines (VAWTs) demonstrate significant potential that can address the existing challenges of the wind turbine industry. Current work aims to investigate the practicality of this potential for the wind energy sector. To this end, the benefits of employing Darrieus turbines for domestic and industrial applications, isolated operation, and on/offshore windfarm applications have been explored. It is apparent that Darrieus VAWTs are better suited to a wide range of environments, whether they are deployed in isolation or integrated systems, and whether they are utilized on a small or large scale. Darrieus VAWTs are adaptable to urban unsteady variable wind, are less expensive on large scales, provide higher power density at the windfarm level, and provide stability for offshore platforms. Nevertheless, challenges remain in fully harnessing VAWT potential rooted in their complex aerodynamics. This serves as a primary challenge for VAWTs to address the challenges of the wind turbine industry in line with the 2050 roadmap.

Synthesis of {AlMo14O44}-Based Supramolecular Structures with High Proton Conductivity.

Polyoxometalates (POMs) are esteemed for their remarkable stability and exceptionally high proton conductivity, rendering them ripe for extensive exploration owing to their research significance. Herein, we synthesized two bimolybdenum-capped {AlMoVI8MoV6O44} cluster-based coordination polymers through a solvothermal method. Single-crystal X-ray diffraction analysis elucidates that H[(H2bimb)3(AlMoVI8MoV6O44)] [bimb = 1,4-bis(imidazole-1-ylmethyl)benzene, compound 1] is the POMs-organic supramolecular structure. The introduction of zinc ions into the reaction environment facilitated the connection of initially dispersed ligands, which yielded the well-ordered structure H3[Zn2(bimb)4(AlMoVI8MoV6O44)]·4H2O (compound 2) with a layer distance of 11.8 Å. The proton conductivities (σ) of two compounds were measured under conditions of 85 °C and 98% relative humidity (RH), resulting in values of 3.89 × 10-2 and 4.76 × 10-2 S·cm-1, respectively. This study presents a novel approach to fabricating POMs as proton conductors through structural design and manufacturing adjustments.

Structural design and test of superconducting magnet coil for the cooling storage ring external-target experiment

Abstract Heavy ion collision is an unique method for studying cold and dense nuclear matter in labs. The Cooling Storage Ring (CSR) External-target Experiment (CEE) at the Heavy Ion Research Facility in Lanzhou (HIRFL), China, is the first multi-purpose nuclear physics experimental device to operate in the GeV energy range. One of the key parts is a large acceptance dipole magnet, which is used to bend particles so that they can be detected by various detectors. A superconducting coil with the size of 3.1 m ×3.6 m × 2 m was designed to verify the rationality of the scheme. Although the coil-dominated superconducting magnet with NbTi has been used to reduce the weight and size of the magnet, large deformation and stress will occur in the cooldown and excitation stages owing to the large volume and weight. Therefore, it is crucial to design a reasonable structure to ensure the strength of the magnet and prevent the magnet from interfering with other components due to large deformation, and even the possibility of quenching. A truss supporter is proposed for the support of the superconducting coil. In this study, the structural design of the cold mass of a superconducting magnet is introduced, and its mechanical behaviors during cooldown and excitation are analyzed in detail. To verify the feasibility of the coil design and process route, a sub-size prototype was manufactured and tested at 4.2 K and reached the design current successfully.

Aircraft joint structure lightweight design

PurposeThe purpose of this article is to carry out a lightweight design of the joint structure according to the service condition of the joint.Design/methodology/approachThe finite element analysis techniques are used along with the variable density structure topology optimization method, the multi-island genetic algorithm for structural dimension optimization and the fatigue life analysis method.FindingsUtilizing the topology optimization method and size optimization method, the mass of the optimized model for the A100 material model is 9.67 kg. Compared to the pre-optimized model, the mass decreases by 8.23 kg, representing a weight reduction of 46.0% in the optimized model; the fatigue life of the aircraft joint is predicted to be a maximum of 1,460,017 cycles.Originality/valueThe originality of this study is that it provides new design ideas for the lightweight design of aircraft load-bearing structures.

Infrared Light Activated Highly Efficient Cell Therapy Using Flower‐Shaped Microstructure Device

AbstractIn this pioneering study, an infrared light‐activated highly efficient and uniform, small to large biomolecular delivery into various cell types is developed using a flower‐shaped microstructure device (FMD). Featuring a unique structural design, this FMD consists of 8 µm in length, with edges of ≈3 and 20 µm gaps between FMD microstructure. When subjected to IR laser exposure at 1050 nm, the FMD triggers the generation of photothermal cavitation bubbles, exerting jet fluid flow on the cell's plasma membrane surface, and facilitating biomolecule delivery into cells. The platform achieves efficient intracellular delivery spanning various biomolecules — from low‐molecular‐weight propidium iodide dye to higher molecular weight siRNA, plasmid, and enzymes — across human cervical (SiHa), mouse fibroblast (L929), and neural crest‐derived (N2a) cancer cells, ensuring consistently high efficiency without compromising cell viability. 95% delivery efficacy and 96% cell viability are achieved for smaller molecules like PI dye in L929 cells. For larger biomolecules such as enzymes, transfection efficiency reached 82%, and cell viability is nearly 90% in SiHa cells. This is confirmed via confocal microscopy and flow cytometry, the FMD‐based delivery system holds broad potential for cellular diagnostics and therapeutics, promising significant advancements in cellular research and biomedical treatments.

Crucial role of structural design on performance of cryogel-based EMI shields: an experimental review.

In the field of electromagnetic interference (EMI) shielding with materials based on highly porous constructsconstructs, such as foams, cryogels, aerogels and xerogels, a significant challenge lies in designing structures that primarily absorb rather than reflect incident electromagnetic waves (EMWs). This goal necessitates a dual focus on the electrical conductivity and the internal porosity of the given porous material. To explore these issues, we fabricated various graphene oxide (GO)-based cryogels by molding, emulsion templating, chemically-induced gelation, freeze-casting, and liquid-in-liquid streaming. Following thermal annealing to enhance electrical conductivity for effective EMI shielding, we assessed the physicochemical, mechanical and structural characteristics of these cryogels. Notably, the cryogels exhibited distinct EMI shielding behaviors, varying significantly in terms of primary shielding mechanisms and overall shielding effectiveness (SET). For example, chemically-crosslinked cryogels, which showed the highest electrical conductivity, predominantly reflected EMWs, achieving a reflectance of approximately 70% and a SET of 43.2 dB. In contrast, worm-like cryogels, despite having a similar SET of 42.9 dB, displayed a unique absorption-dominant shielding mechanism. This was attributed to their multi-scale porosities and numerous internal interfaces, which significantly enhanced their ability to absorb EMWs, reflected in an absorbance of 54.7%. Through these experiments, our aim is to provide key heuristic rules for the structural design of EMI shields.

Electromagnetic Interference Shielding Films: Structure Design and Prospects.

The popularity of portable and wearable flexible electronic devices, coupled with the rapid advancements in military field, requires electromagnetic interference (EMI) shielding materials with lightweight, thin, and flexible characteristics, which are incomparable for traditional EMI shielding materials. The film materials can fulfill the above requirements, making them among the most promising EMI shielding materials for next-generation electronic devices. Meticulously controlling structure of composite film materials while optimizing the electromagnetic parameters of the constructed components can effectively dissipate and transform electromagnetic wave energy. Herein, the review systematically outlines high-performance EMI shielding composite films through structural design strategies, including homogeneous structure, layered structure, and porous structure. The attenuation mechanism of EMI shielding materials and the evaluation (Schelkunoff theory and calculation theory) of EMI shielding performance are introduced in detail. Moreover, the effect of structure attributes and electromagnetic properties of composite films on the EMI shielding performance is analyzed, while summarizing design criteria and elucidating the relevant EMI shielding mechanism. Finally, the future challenges and potential application prospects of EMI shielding composite films are prospected. This review provides crucial guidance for the construction of advanced EMI shielding films tailored for highly customized and personalized electronic devices in the future.

Learning From Nature: The Rational Non‐Centrosymmetric Structural Design in the Honeycomb‐Like Gaudefroyite Family

Learning From Nature: The Rational Non‐Centrosymmetric Structural Design in the Honeycomb‐Like Gaudefroyite Family

Design and implementation of corrosion-resistant multitasking cell stainers.

Compared with machine staining, traditional manual staining faces various problems, such as a low preparation success rate, low efficiency, and harm to the human body due to corrosive gases. Therefore, a stainer that is of low cost, has strong corrosion resistance, and is suitable for small-batch preparation should be developed. In this study, by choosing a rotary scheme as the structural basis, a reusable container cover and a master-slave manipulator cooperation scheme are developed, which greatly improve the space utilization rate. Through material selection and structural design, in the designed stainer, effective protection against strong acids with high volatility and permeability is realized, thereby eliminating the corrosion issue. Using the designed splitting-running algorithm for the dyeing procedure, simultaneous multistaining is realized, which significantly improves the staining efficiency. Compared with large-sized stainers, the cost of the proposed stainer is very low, which will help popularize early screening for cervical cancer in low- and middle-income countries.

Arup Group Limited: putting trust in the trust

Research methodology The data set used to write this case was collected from 83 public sources, including company communications, company journals and reports and the company website, along with newspaper articles, industry reports, scientific articles and case studies. The data set was used to analyse both the industry and firm in which Arup operated to draw conclusions about the firm’s strategy and competitive advantage, specifically, as it relates to trust and knowledge management. Case overview/synopsis Alan Belfield, an employee of Arup Group Limited for 29 years, and the company’s chairman since 2019, had witnessed significant growth since he first joined the firm. Operating globally, Arup had a proud past; since 1946, the company had served 6,931 clients across 143 countries, leading to its important contribution to many world-renowned landmarks within the built environment. From 2018 to 2020, revenue at the global multiservice engineering company had grown almost £250m [1] to £1.809bn. Over the past few years and as 2021 came to an end, the global engineering services industry had experienced a flood of mergers and acquisitions, as the industry grew towards maturity and clients looked for full-service solutions. Arup’s strategy had proven successful in the past, evidenced by its capacity to grow revenues and partake in the design of well-known structures and buildings. However, with the trend towards consolidation, as Arup headed into 2022, how could the firm retain its position as one of the global leaders in the industry over time? Complexity academic level The case can be used in business courses on global strategic management at the bachelor and master levels, as it applies key strategic management concepts within a global context. The case focuses primarily on the transnational corporation (Bartlett and Ghoshal, 2002) and how it creates value through strategy and structure. Instructors who wish to integrate the human resource management aspect into the course are provided with optional material, including an additional reading, along with an assignment question and associated analysis and teaching guidance.

Optimization of vehicle crashworthiness problems using recent twelve metaheuristic algorithms

Abstract In recent years, numerous optimizers have emerged and been applied to address engineering design challenges. However, assessing their performance becomes increasingly challenging with growing problem complexity, especially in the realm of real-world large-scale applications. This study aims to fill this gap by conducting a comprehensive comparative analysis of twelve recently introduced metaheuristic optimizers. The analysis encompasses real-world scenarios to evaluate their effectiveness. Initially, a review was conducted on twelve prevalent metaheuristic methodologies to understand their behavior. These algorithms were applied to optimize an automobile structural design, focusing on minimizing vehicle weight while enhancing crash and noise, vibration, and harshness characteristics. To approximate the structural responses, a surrogate model employing radial basis functions was utilized. Notably, the MPA algorithm excelled in automobile design problems, achieving the lowest mass value of 96.90608 kg during both mid-range and long-range iterations, demonstrating exceptional convergence behavior.

Climbing Plant‐Inspired Multi‐Responsive Biomimetic Actuator with Transitioning Complex Surfaces

AbstractBionic robots have great potential in healthcare, rescue, and surveillance. However, most soft actuators can only realize one or two deformation modes, which largely limit the application in complex environments. This study develops electric/Infrared (IR) light/magnetic multi‐field coupling soft actuators by combining liquid crystal elastomers (LCE), liquid metal (LM) and magnetic Ecoflex (Mecoflex). Originated from the synergistic effect of the differed thermal expansion and the liquid crystal phase transition, the actuator can realize outstanding large deformations (bending angle > 300°) at ultra‐low voltages (1.0 V). In addition, by designing the molecular orientation in the LCE layer and programming the magnetization in the Mecoflex layer, the bending or helical bending deformations can be controlled under electric/magnetic and IR light/magnetic coupling actuation. Based on the complex deformation capability, bionic climbing plants and two kinds of quadrupedal robots are developed. With the structural design of the quadrupedal robots, they can flexibly switch deformations to pass through complex environments by controlling the externally applied coupling fields, which demonstrates their broad potential in practical applications.

Parameter-normalized probabilistic seismic demand model considering the structural design strength for structural response assessment

The Probabilistic Seismic Demand Model (PSDM) is a crucial component of the performance-based seismic design framework when establishing the relationship between the ground motion intensity measure (IM) and the engineering demand parameter (EDP). The definitions of IMs and EDPs introduce varying degrees of uncertainty into the PSDM and notes different fragility or hazard analysis results. In accordance with the elastic limit state of the structural seismic response, this study normalizes two key parameters, the IM and EDP, within the PSDM. Normalized EDP (EDPN) is the ratio of the structural response to the elastic limit state of the structure, as defined by the onset of the strength yielding of the main structural element. Similarly, the IM (IMN) is normalized based on corresponding ground motions (scaled) that cause the structure to offer an elastic limit state response. This means that structural design strength is considered in IMN following the construction of a parameter-normalized PSDM. The study examined two typical isolated bridges presented their hazard curves with IMN. The results show that IMN can unify the efficiency and sufficiency of different IMs and reduce uncertainty in the PSDM. The assessment error of the structural elastic limit state for its design strength had little effect on the parameter-normalized PSDM, so the model is robust. Additionally, the IMN outperformed traditional IMs for efficiency and sufficiency in most instances.

Activating Metal-Organic Cages by Incorporating Functional M(ImPhen)3 Metalloligands: From Structural Design to Applications.

ConspectusThe emulation of ingenious biofunctions has been a research focus for several decades. Metal-organic cages (MOCs), as a type of discrete supramolecular assembly with well-defined shapes and cavities, have aroused great interest in chemists to imitate natural protein cages or enzymes. However, to genuinely achieve tailored functionalities or reactivities of enzymes, the design of cage structures combining both the confined microenvironment and the active site is a prerequisite. Therefore, the integration of functionalized motifs into MOCs is expected to provide a feasible approach to construct biofunctional confined nanospaces, which not only allows the modulation of cage properties for applications such as molecular recognition, transport, and catalysis but also creates unique microenvironments that promote enzymatic effects for special reactivities and selectivities, thereby providing a versatile platform to achieve exceptional biomimetic functions and beyond.In this Account, we specifically focus on our research toward engineering active confined-nanospaces in MOCs via incorporation of M(ImPhen)3 metalloligands, a typical tris-chelate coordination moiety comprising imidazophenanthroline ligands and variable metal ions, as the principle functional units for stepwise assembly of active-MOCs. Starting from their structure design and merits, we describe the versatility of M(ImPhen)3 centers for multifunctionalization of the confined cage-nanospaces. By integrating different metal ions like Ru, Os, Fe, Co, Ni, Zn, the metal ion inherent properties, e.g., redox activity of Fe/Co-centers, chirality, and photoactivity of Ru-centers, and dynamics of Co/Zn-centers, could be integrated and tailored on the cages as isostructural nanosized containers or reactors. Changing the Pd or Pt cage vertices to organic clips could remarkably enhance acid-base stability and endow cages with flexibility and allostery. Utilization of ImPhen organic ligands containing imidazole groups introduces proton transfer capability, which can couple with the high-positive charges on the cage to create amphoteric microenvironments in the porous open-cage solution. Moreover, the nonplanar stereoconfiguration of M(ImPhen)3 confers multiple peripheral pockets on the cage, which render multisite, high-order, and dynamics guest binding for the benefit of applications such as drug delivery, molecular separation, and catalytic turnover.The construction of active-MOCs from tailorable M(ImPhen)3 metalloligands provides us with a new perspective on their structural design and functionalities. Merging the cage confinement with distinct physicochemical properties on a supramolecular level makes it practical to realize synergistic and cooperative effects for functionality enhancement beyond molecular components or the reactivity different from the bulky solution, which could largely expand the potential of MOCs as a multirole platform to wide application scenarios such as artificial photosynthesis, unconventional catalysis, and theranostic nanomedicine.

Study of the Micro-Vibration Response and Related Vibration Isolation of Complex Traffic Load-Induced Experimental Buildings

In view of the high-sensitivity vibration effect of precision instrument laboratory buildings under the influence of surrounding traffic loads, field micro-vibration tests under various working conditions were carried out based on actual projects. Combined with numerical simulation, measured data served as input loads to simulate the vibration effect of various traffic loads on the floor of a building structure, and the structural vibration laws under the comprehensive action of various loads were analyzed. The vibration isolation effect of the isolation ditch on the oblique orthogonal load was investigated according to the corresponding safety index. The results show that the main frequency components of the site vibration frequency caused by various traffic loads are approximately 25 Hz and that the root-mean-square speed value is stable below VC-E, which meets the design requirements. Under the comprehensive action of multiple loads, the site structure will produce a vibration amplification effect, which is obvious when all types of loads are distributed symmetrically and the curve distribution is controlled by load factors with large amplitudes. The isolation effect of a small isolation ditch is best when it is located close to the source and the building. The depth of the isolation ditch must be greater than the maximum depth of the source to achieve better results, and the width has little influence. The effect of a small isolation trench on vertical vibration is poor, and the oblique orthogonal triaxial load has a counteracting effect on the vertical component. Thus, additional structural vibration isolation measures are needed. The research results provide a reference for engineering vibration isolation, damping measures, and structural design.

Prediction of confined compressive strength of concrete column strengthened with FRCM composites

AbstractNowadays, retrofitting and rehabilitation of deteriorated reinforced concrete structures are becoming a growing need of the construction industry instead of demolishing aged structures. The application of fabric‐reinforced cementitious matrix (FRCM) on the existing concrete structures is one of the sustainable solutions to retrofit the concrete structures. This study used machine learning (ML) models such as linear regression (LR), support vector machines (SVM), and adaptive neuro‐fuzzy inference systems (ANFIS) to estimate the compressive strength (CS) of columns wrapped with FRCM. The experimental dataset of 301 column specimens was collected including input parameters such as cross‐sectional properties, mechanical properties of concrete and steel, and characteristics of FRCM material. Apart from ML models, seven analytical models were also used to compare the accuracy and precision of ML models. The results illustrate that the ANFIS model outperformed other ML models and established itself as a dependable and precise model. The R‐value of the ANFIS model was 0.9816, whereas R‐values of 0.9269 and 0.9572 were achieved by LR and SVM models, respectively. In addition, the MAPE value acquired by the ANFIS model was 1.52% which was lower than those of the LR model by 73.24%, and the SVM model by 60.60%, respectively. As the precision of the ANFIS model was higher as compared with SVM and LR models, so, the developed ANFIS‐based mathematical model can be easily used to predict the CS of FRCM‐strengthened concrete columns. The developed model is accurate, economical, and fast; and can be utilized by FRCM applicators and structural designers.

Optimal Design of Multilevel Composite Lubrication Structures on Sliding Guide Rail Surfaces

To optimize the crawling phenomenon of slides under circumstances of low speed and a heavy load, a composite lubrication structure is adopted to alleviate the crawling phenomenon. The response surface optimal-design method establishes a quadratic mathematical model for multistage composite lubrication structure parameters, including crawling time and average friction coefficient. The optimal combination parameters of multistage composite lubrication structures have been determined. The optimal ratio of lubricating oil to molybdenum disulfide (MoS2) has been identified, and a composite lubrication structure has been proposed to enhance the crawling phenomenon and friction performance of sliding guide rails under medium-speed and medium-load conditions. These research outcomes indicate that when low speed and a heavy load are present, the crawling time and friction coefficient initially diminish and subsequently augment as the width, spacing, and cycle length of the sinusoidal texture and the diameter of the hexagonal pit expand. The optimum configuration of multistage composite lubrication structures is as follows: The width of the sine-wave texture b amounts to 0.15 mm, the cycle length e is 2 mm, the spacing c is 1.5 mm, and the diameter of the hexagonal pit d is 0.2 mm. When the mass ratio of guide oil to MoS2 is 2:1, it exhibits supreme crawling resistance and antifriction attributes. In circumstances involving a medium load and speed, multistage composite lubrication structures manifest pre-eminent friction performance. These data can steer the design of multistage composite lubrication structures on the surface of slide rails.

Regulating Intermolecular Hydrogen Bonds in Organic Cathode Materials to Realize Ultra‐stable, Flexible and Low‐temperature Aqueous Zinc‐organic Batteries

Rational design of molecular structures is one of the effective strategies to obtain high‐performance organic cathode materials. However, besides the optimization of single‐molecule structures, the influence of the "weak" interaction forces (e.g. hydrogen bonds) in organic cathode materials on the performance of batteries should be fully considered. Herein, three organic small molecules with different numbers of hydroxyl groups (namely nitrogen heterocyclic tetraketone (DAB), monohydroxyl nitrogen heterocyclic dione (HDA), dihydroxyl nitrogen heterocyclic dione (DHT)) were selected as the cathodes of aqueous zinc ion batteries (AZIBs), and the effect of the intermolecular hydrogen bonds on their electrochemical performance was studied for the first time. Clearly, the stable hydrogen‐bond networks built through the hydroxyl groups significantly enhance the cycle stability of organic small‐molecule cathodes and facilitate rapid proton conduction between the hydrogen‐bond networks through the Grotthuss mechanism, thereby endowing them with excellent rate performance. In addition, a larger and more dense two‐dimensional hydrogen‐bond network can be constructed through multiple hydroxyl groups, further enhancing the structural stability of organic small‐molecule cathodes, giving them better cycle tolerance, excellent rate performance, and extreme environmental tolerance.

A Strain-Controlled Finite Strain Model for CRD Consolidation of Saturated Clays Considering Non-Linear Compression and Permeability Relationships

Consolidation is the combined phenomenon of the compression and groundwater seepage of clay. Accurate evaluation of the consolidation characteristic is essential for the design, construction, and long-term stability of geotechnical structures. In this study, a strain-controlled non-linear finite strain model for constant rate-of-deformation (CRD) consolidation was developed for quickly and reliably predicting the consolidation behavior of clay soils. The model can account for any form of non-linear compression and permeability relationships, thus considering variations in the coefficient of consolidation. Being strain-controlled, it overcomes the limitations of stress-controlled models which require complex numerical iteration. The validity and accuracy of this model were verified through rigorous comparisons with both numerical simulations and experimental data. For normally consolidated soils, a non-linear e-lgσ′compression model was used instead of a linear compression model. For overconsolidated soils, the Harris function compression model was determined to be recommended to overcome the discontinuities in total stress and pore pressure caused by the traditional piecewise e-lgσ′ model. It was also found that determining the steady state of consolidation for normally consolidated soils should use the non-linear method, while the linear method is suggested to be adopted for overconsolidated soils.