Edge Thickness Research Articles

Variable offsets and processing of implicit forms toward the adaptive synthesis and analysis of heterogeneous conforming microstructure

AbstractThe synthesis of porous, lattice, or microstructure geometries has captured the attention of many researchers in recent years. Implicit forms, such as triply periodic minimal surfaces (TPMS) has captured a significant attention, recently, as tiles in lattices, partially because implicit forms have the potential for synthesizing with ease more complex topologies of tiles, compared to parametric forms. In this work, we show how variable offsets of implicit forms could be used in lattice design as well as lattice analysis, while graded wall and edge thicknesses could be fully controlled in the lattice and even vary within a single tile. As a result, (geometrically) heterogeneous lattices could be created and adapted to follow analysis results while maintaining continuity between adjacent tiles. We demonstrate this ability on several 3D models, including TPMS.

Energy conversion mechanisms in turbomachines for high-temperature endothermic reactions: Redefining energy quality

A new class of turbomachines, called turbo-reactors, have emerged to decarbonize high-temperature chemical processes. These applications unlock a new aerothermochemical design space for turbomachines. This paper explains how the turbo-reactor has the potential to be a “chemically tuned” device. In contradiction with conventional design wisdom, this can be achieved by balancing entropy generation within the flow against heat absorption by the reaction. This enables the “design” of a reaction-efficient temperature profile. To do this, it is necessary to understand and quantify the distribution of the entropic and isentropic mechanisms responsible for energy conversion. This paper uses high- and low-fidelity computations to decompose the energy conversion process into mechanisms based on a spatial decomposition. A range of Mach and Reynolds number regimes are studied, as well as a multistage configuration without vaneless space. The energy conversion breakdown analysis indicates that the entropic energy conversion dominates over the isentropic component with a contribution of 65%. The dominant source of entropy production is viscous dissipation generated by the thick diffuser trailing edge, accounting for 25% of the total. The shock system provides 20% of the energy conversion, almost entirely due to reversible pressure rise rather than entropy production. The energy conversion coefficient is independent of Reynolds number over engine-relevant conditions, whereas Mach effects are more significant. Across the Mach numbers range 1.1 to 1.5, the energy conversion coefficient increases by 20%. This is lower than expected as a result of the opposing effects of reversible and irreversible energy conversion contributions.

Tricuspid valve maladaptation in sheep with biventricular heart failure: The posterior and septal leaflets.

Tricuspid valve leaflets are dynamic tissues that can remodel in response to altered biomechanical and hemodynamic loads. The anterior, posterior, and septal leaflets exhibit distinct morphology, composition, and mechanical properties, resulting in varying in vivo strains. We hypothesized that these differences would result in leaflet-specific remodeling changes in a sheep model of biventricular heart failure. Previously, we reported significant maladaptive changes in the anterior leaflet (Meador et al., 2020b). Here, we extended the analysis to the posterior and septal leaflets and observed a lesser but notable remodeling response. Both the diseased posterior and septal leaflets showed increased free edge thickness and valvular interstitial cell activation. However, only the posterior leaflet exhibited increased circumferential stiffness and collagen content. In contrast, only the septal leaflet increased in area and displayed signs of endothelial-to-mesenchymal transition. These findings emphasize the importance of considering leaflet-specific remodeling when developing computational models or targeted treatment strategies for tricuspid valve disease.

Wake Dynamics of Complex Turning Vanes Using Time-Resolved Particle Image Velocimetry Measurements

Abstract The use of turning vanes spans multiple engineering disciplines such as aerospace, ocean, and biomedical to effectively turn an otherwise uniform flowfield and achieve desired downstream flow angles. The presented work investigates the wake dynamics generated by sets of complex turning vanes which contained nonaxisymmetric geometries, spanwise variations in turning angle, and multiple vane junctions. Time-resolved particle image velocimetry (TR-PIV) measurements were performed to collect three-component velocity data downstream of the vane pack geometries. As the vanes contained blunt trailing edges (TEs), large-scale periodic structures (von Kármán vortices) dominated the unsteady wakes. Two postprocessing methods, proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD), were employed to extract the wake energy or enstrophy content, corresponding spatial modes, and associated frequencies. This was completed for various parameters such as Reynolds number, vane turning angle, and vane trailing edge thickness. Spatial POD analyses showed that zero-turning vanes contained similar dynamics to that of a circular cylinder, and the total wake energy distributions were affected by freestream velocity. A spectral POD analysis in the wake of vane junctions found that the junction flow contained significant coherent content and gave some insight into the mean flow. Finally, vane parameters such as turning angle and TE thickness were found to play a large role in modifying the enstrophy content of the large-scale shedding modes.

Relationship Between Wavy Liquid Film Dynamics and Droplet Formation From Trailing Edge

Abstract Erosion of steam turbine blades due to coarse droplet impingement is a serious problem. The physical relationship is still elusive between the dynamics of wavy liquid film on a wall and the droplet dispersion from the trailing edge. In this study, we experimentally and theoretically investigate the liquid film subjected to the turbulent airflow and following fragmentation process under well-controlled flow conditions, where the airflow velocity is up to 100 m/s, and initial liquid film velocity is 0.06 and 0.10 m/s, and trailing edge thicknesses are 0.5, 1.0, and 2.0 mm. By applying the developed PLIF based method with no use of artificial threshold of brightness, we quantify the film thickness and interfacial friction factor. As the airflow velocity increases, the liquid film instability promotes and the interfacial friction factor increases, much exceeding the Blasius correlation. When the liquid film reaches the trailing edge, several liquid columns extend by the Rayleigh-Taylor instability. We identify that the interfacial friction factor to accelerate the ligament corresponds to the Blasius correlation, distinct from the one on the wavy liquid film upstream. Incorporating the identified two interfacial friction factors, we successfully formulate the diameter of ligament as the characteristic lengthscale of the spreading droplet downstream. Derived formulation for the droplet statistics is well validated by the experimental results of mean and maximum diameters and size distribution.

Roughness analysis on porcelain sectional surface of porcelain fused to Co-Cr alloy endocrowns

This study aims to compare the roughness between the central and edge points on the porcelain sectional surface of porcelain fused to Co-Cr alloy endocrowns. Utilizing anatomical data from average molar dimensions, a simplified model for the endocrowns was created. Eight porcelain fused to Co-Cr alloy endocrowns were fabricated with an edge thickness of 0.3 mm. Following casting, firing, cutting, and polishing procedures, the roughness on porcelain sectional surface at both the central and edge points of the inner crown was assessed using an atomic force microscope (AFM). The roughness measurement (Sq value) for the central point on porcelain sectional surface was (10.46 ± 3.37 nm), and for the edge point, it was (10.50 ± 1.99 nm). There was no statistically significant distinction between the central and edge points in terms of roughness. Despite the uneven thickness of the inner crown in porcelain fused to Co-Cr alloy endocrowns, it was observed that this disparity had negligible impact on the internal microstructure of the porcelain. Therefore, its application in dental clinical settings could be deemed viable.

Experimental study on compression properties of composite aluminum honeycomb sandwich structures

AbstractThe mechanical properties of the carbon fiber and glass fiber composite honeycomb sandwich structure were studied through compression experiments. The influence of different aluminum honeycomb edge lengths, upper and lower panel thickness, aluminum honeycomb thickness, and loading speed on the compression failure load of carbon fiber composite laminates sandwich structure is analyzed. The influence of different aluminum honeycomb edge lengths and thicknesses on the compression failure load of glass fiber composite laminates sandwich structure was studied. The results show that the thickness of the panel has a significant effect on the failure load of the carbon fiber composite laminate sandwich structure, and the loading speed has a significant effect on the failure load of the carbon fiber composite laminate sandwich structure. The greater the loading speed, the greater the value of the failure load. The edge length and thickness of the aluminum honeycomb have a certain effect on the damage load of the carbon fiber composite laminates sandwich structure, but the influence on the mechanical properties of the glass fiber composite laminates sandwich structure is much greater.Highlights The compression performance of composite sandwich structures was experimentally studied. The influence of composite panel thickness was studied. The influence of aluminum honeycomb edge length and thickness was studied. The influence of loading speed was studied.

근시용 안경렌즈에서 가장자리 두께와 무게 예측

근시용 안경렌즈에서 가장자리 두께와 무게 예측

Optimal section design of surface piercing propeller using artificial neural networks algorithm

ABSTRACT Section optimisation of a surface piercing propeller (SPP) with the combination of artificial neural networks and NSGA II algorithm is investigated in this research. The blade section have a sharp leading edge and thick trailing edge. The geometry of this propeller is mostly designed experimentally, and comprehensive studies have not been performed to examine its parameters. In this regard, the propeller's parametric geometry is designed based on the cubic B-spline method. The SPP was first fabricated and tested, and the simulated data of the tested propeller were verified. Then, limited data were extracted according to a verified CFD model based on which the ANN was trained. The ANN results indicated the mean square error of the trained network is 3e-9, 1e-7, and 1e-7 for training, validation, and test data, respectively. comparing the optimisation and experimental results showed a relative error amounting to 3.5% in thrust and 4.24% in torque.

Computational investigation of the effect of the trailing edge thickness on the wind turbine performance

Trailing edge (TE) thickness is a manufacturing constraint in blade design, especially for airfoils with a sharp TE. To achieve a specific TE thickness, blade geometry is often modified during the design process, typically in the outer zone of the blade where the airfoil’s TE is thinner. This area has a significant impact on energy production and loads. Quantifying the effect of TE thickness modifications is crucial for making informed design decisions.Therefore, this study quantifies and compares the impact of linear and polynomial geometry modifications on airfoil aerodynamics and turbine performance. Xfoil and OpenFAST were used to calculate these performance variations in the well-known NREL 5 MW wind turbine. The TE thickness of the model was modified to meet various manufacturing constraints, ranging from no restriction to a limit of 12mm TE thickness.In terms of the aerodynamic behavior of the airfoils, the maximum efficiency of airfoils with low relative thickness decreases as the TE thickness increases. Annual Energy Production shows a reduction of up to 0.42% for the worst case, while blade root loads increase by up to 20%. For low relative thickness airfoils, the linear method has proven to be a better option with less impact on performance.

Microstructure-dependent deformation mechanisms and fracture modes of gradient porous NiTi alloys

Gradient porous structures based on triply periodic minimal surfaces offer exceptional specific strength and multi-functionality. However, strain heterogeneity complicates their deformation mechanisms and fracture modes. In this study, we fabricated a series of gradient porous NiTi alloys based on gyroid (G), diamond (D), and I-WP (I) unit cells, with porosities ranging from 50% to 70%. Surprisingly, the I structure exhibited an abnormally high compressive strength of nearly 600 MPa at around 50% porosity, more than twice that of the G and D structures. This performance gap was attributed to the activation of mixed deformation mechanisms and distinct fracture modes. While the G structure showed a uniform radial strain distribution, the D and I structures displayed pronounced radial strain gradients with concentrated central strains. The D structure deformed through relative sliding of oblique struts, while the I structure maintained macrostructural stability, with thick edge struts providing continuous strain hardening until monolithic fracture. This unique deformation behavior results from the synergistic effects of its intrinsic macrostructural stability, significant radial strain gradients, and sufficiently thicker edge struts. The integration of metallurgical and architectural design principles represents a novel approach to tailoring the mechanical properties of gradient porous metals for advanced applications.

Development of laser-arc hybrid welding process of butt joint for bogie pipe crossbeam components

High-speed railway vehicle bogies are the main load-bearing components, which are welded together from steel plates and tubes. Butt joint and T-joint are the main types and the joint thickness is between 8–20mm. The stability of laser-arc hybrid welding (LAHW) process correlated strongly with keyhole behaviour. In this paper, the common quality defects in full penetration root pass by LAHW were analysed. Controlling the root gap is adopted to stabilize the keyhole, to improve the stability of weld quality. A novel type of butt joint with micro structure based on Y-shaped grooves has been designed, to meet both the requirement of controlling root gap and industrial large-scale batch production. Two new structure parameters, 2 mm of the remaining blunt edge thickness and 0.3 mm of the half width of root opening, were proved by the flat plates welding test. Finally, the joint with micro structure and the root pass welding parameters were transferred to the welding process of tube crossbeam components. The LAHW process verification was completed, and the test results showed the process meets the requirements of ISO 15614.

A quantitative weight-of-evidence method for confidence assessment of adverse outcome pathway networks: A case study on chemical-induced liver steatosis

The field of chemical toxicity testing is undergoing a transition to overcome the limitations of in vivo experiments. This evolution involves implementing innovative non-animal approaches to improve predictability and provide a more precise understanding of toxicity mechanisms. Adverse outcome pathway (AOP) networks are pivotal in organizing existing mechanistic knowledge related to toxicological processes. However, these AOP networks are dynamic and require regular updates to incorporate the latest data. Regulatory challenges also persist due to concerns about the reliability of the information they offer. This study introduces a generic Weight-of-Evidence (WoE) scoring method, aligned with the tailored Bradford-Hill criteria, to quantitatively assess the confidence levels in key event relationships (KERs) within AOP networks. We use the previously published AOP network on chemical-induced liver steatosis, a prevalent form of human liver injury, as a case study. Initially, the existing AOP network is optimized with the latest scientific information extracted from PubMed using the free SysRev platform for artificial intelligence (AI)-based abstract inclusion and standardized data collection. The resulting optimized AOP network, constructed using Cytoscape, visually represents confidence levels through node size (key event, KE) and edge thickness (KERs). Additionally, a Shiny application is developed to facilitate user interaction with the dataset, promoting future updates. Our analysis of 173 research papers yielded 100 unique KEs and 221 KERs among which 72 KEs and 170 KERs, respectively, have not been previously documented in the prior AOP network or AOP-wiki. Notably, modifications in de novo lipogenesis, fatty acid uptake and mitochondrial beta-oxidation, leading to lipid accumulation and liver steatosis, garnered the highest KER confidence scores. In conclusion, our study delivers a generic methodology for developing and assessing AOP networks. The quantitative WoE scoring method facilitates in determining the level of support for KERs within the optimized AOP network, offering valuable insights into its utility in both scientific research and regulatory contexts. KERs supported by robust evidence represent promising candidates for inclusion in an in vitro test battery for reliably predicting chemical-induced liver steatosis within regulatory frameworks.

Numerical Investigation of the Effect of Trailing Edge Thickness of Simulated Ceramic Matrix Composite Blades on Loss Profiles

Abstract Ceramic matrix composite (CMC) is an enabling material allowing higher turbine inlet temperatures and possibly resulting in better thermal efficiency of gas turbine engines. This is because CMC layers with environmental barrier coating have significantly higher thermal limits (∼1755 K) compared with the more conventional alloyed metallic blades. CMCs possess a complex fabrication process resulting in different geometrical characteristics than metallic blades (e.g., larger trailing edge thickness, large leading-edge curvature, etc.). It is therefore desirable to assess the aerodynamic performance of the CMC blades using experimental and numerical simulations. To investigate, three different CMC blades with varying trailing edge thicknesses were numerically simulated. Both large-eddy simulation with the dynamic subgrid closure as well a recently implemented Reynolds-averaged Navier–Stokes coupled with an intermittency function-based transition model were utilized. Two sets of experimental test points with different Reynolds numbers at a given high-freestream turbulence range (Tu = ∼10–13%) were considered. The predicted pressure loading profiles, total loss distributions, and integrated loss of the three different CMC blades were computed and comparisons against the experimental data are presented herein. It was found that the mixing loss forms a larger proportion of the overall loss as the trailing edge thickness increases.

基于ANSYS/LS-Dyna旋耕刀切土仿真分析及优化

Mini-tiller is an indispensable agricultural machinery in hilly and mountainous areas of China. Rotary blade is an important working part of mini-tiller, which directly affects the operation quality and power consumption of mini-tiller. In order to reduce the cutting resistance and power consumption of the rotary blade of mini-tiller, the cutting process of the rotary blade was analyzed by numerical simulation, and the tangential bending radius (R), bending angle (β) and edge thickness (c) of the rotary blade were selected as factors to optimize it. After comparing the cutting resistance and cutting power consumption of the rotary blade before and after optimization, the results show that the cutting force of the optimized rotary blade is smaller than that of the rotary blade before optimization. The cutting power consumption of the optimized rotary blade is 2.4% lower than that of the unoptimized rotary blade, which achieves the purpose of drag reduction and consumption reduction.

Analysis and Structural Optimization Test on the Collision Mechanical Model of Blade Jun-Cao Grinding Hammer

Aiming at the problems found in grinding Jun-Cao, such as poor grinding effect and high grinding power of mill, this study proposes a blade Jun-Cao grinding hammer based on the traditional hammer mill. With dynamics model analysis, it had better performance than a traditional hammer. By simulating the operation process in the DEM, forces on Jun-Cao and their motions were analyzed. By optimizing the structural parameters of the hammer blade based on multiobjective optimization using the genetic algorithm, an optimal solution set was obtained as a reference for practical production. Meanwhile, a bench test was designed to compare the traditional rectangular hammer with the new blade hammer regarding the operation effect. The result proved the following: (1) cutting edge length, cutting edge thickness and hammer thickness had a significant influence on the grinding effect and grinding power; (2) a total of 22 optimal solution sets were obtained, based on which the blade hammer with a cutting edge length of 45 mm, a cutting edge thickness of 3 mm and a hammer thickness of 7 mm was finally selected in the bench test; (3) the bench test proved that the blade hammer was generally superior to the traditional rectangular hammer with the output per kilowatt-hour having been improved by 13.55% on average.

Enhancing Deep Edge Detection through Normalized Hadamard-Product Fusion.

Deep edge detection is challenging, especially with the existing methods, like HED (holistic edge detection). These methods combine multiple feature side outputs (SOs) to create the final edge map, but they neglect diverse edge importance within one output. This creates a problem: to include desired edges, unwanted noise must also be accepted. As a result, the output often has increased noise or thick edges, ignoring important boundaries. To address this, we propose a new approach called the normalized Hadamard-product (NHP) operation-based deep network for edge detection. By multiplying the side outputs from the backbone network, the Hadamard-product operation encourages agreement among features across different scales while suppressing disagreed weak signals. This method produces additional Mutually Agreed Salient Edge (MASE) maps to enrich the hierarchical level of side outputs without adding complexity. Our experiments demonstrate that the NHP operation significantly improves performance, e.g., an ODS score reaching 0.818 on BSDS500, outperforming human performance (0.803), achieving state-of-the-art results in deep edge detection.

Near-Infrared Responsive Ag@Au Nanoplates with Exceptional Stability for Highly Sensitive Colorimetric and Photothermal Dual-Mode Lateral Flow Immunoassay.

Lateral flow immunoassay (LFIA) has played a vital role in point-of-care (POC) testing on account of its simplicity, rapidity, and low cost. However, the low sensitivity and difficulty of quantitation limit its further development. Sensitive markers with new detection modes are being developed to dramatically improve LFIA's performance. Herein, a ligand-complex approach was proposed to uniformly coat a thin layer of Au onto Ag triangular nanoplates (Ag TNPs) without etching the Ag cores, which not only retain the unique optical properties from Ag TNPs but also acquire the surface stability and biocompatibility of gold. The localized surface plasmon resonance absorption of these Ag@Au TNPs could be finely adjusted from visible (550 nm) to the second near-infrared region (NIR-II) (1100 nm), and even longer, by simply adjusting the ratio between edge length and thickness. Utilizing the Ag@Au TNPs as new markers for LFIA, a highly sensitive colorimetric and photothermal dual-mode detection of the SARS-CoV-2 nucleocapsid protein was achieved with a very low background. The Ag@Au TNPs showed an exceedingly high photothermal conversion efficiency of 61.4% (ca. 2 times higher than that of Au nanorods), endowing the LFIA method with a low photothermal detection limit (40 pg/mL), which was 25-fold lower than that of the colorimetric results. The generality of the method was further verified by the sensitive and accurate analysis of cardiac troponin I (cTnI). This method is robust, reproducible, and highly specific and has been successfully applied to SARS-COV-2 detection in 35 clinical samples with satisfactory results, demonstrating its potential for POC applications.

Optimization of the Bulk Refractive Index Sensitivity of Silver NanoPrisms

AbstractThe sensitivity and optical properties of silver nanoprisms (triangular plates with round‐truncated corners) are investigated in this paper. Results of boundary element method simulations are compared with experimental results and literature data. Based on electron microscopy images of the synthesized nanoprisms, a single‐particle model is set up for simulations with three running parameters: edge length, thickness, and roundness (defined as the radius of the circumscribed circle divided by the edge length). These geometric parameters can be optimized during chemical synthesis to create sensors with improved sensitivity. The effect of biomolecular layers is also investigated. As a novel approach to improve the agreement between the simulated and experimentally measured extinction spectra, the single‐particle model is extended to consider the variation of the prisms' parameters in the form of distributions. The resulting extinction cross‐section spectra correspond well with the experimental data. The calculated bulk refractive index sensitivity is 670 nm/RIU (RIU stands for refractive index unit) for the single particle model (length = 150 nm, thickness = 10 nm, and roundness = 0.1), while (690 ± 5) nm/RIU for the extended model. The presented model and obtained relations between sensitivity and geometry can be effectively used to design and optimize the fabrication technologies for silver nanoprism‐based sensing applications.

Experimental and numerical investigation on failure behavior of hybrid bonded/bolted GFRP single-lap joints under static shear loading

The mechanical performance of the GFRP (Glass Fiber Reinforced Polymer) hybrid bonded/bolted single-lap joints under static shear loading is investigated. Static loading tests considering the hybrid joints with one bolt, four bolts, and nine bolts were first conducted to study the failure mechanism of hybrid joints, where failure process, rigidity, failure load, and failure modes were focused. Finite element (FE) analysis involving the material degradation and failure laws was also carried out for exploring the internal mechanism of joints’ failure. Based on the verified FE model, the effects of plate thickness and bolt edge distance on the failure capacity and strength of the hybrid joints were further investigated by performing a numerical parametric analysis. Results show that, the failure process of the hybrid joints can be divided into two stages which correspond to the failures of adhesive layer and GFRP plates, respectively. The joint rigidity of joints increases by 98.9 %∼133.1 % comparing the second loading stage to the first stage, and it is found that the rigidity in the first stage is hardly affected by the number of fasten bolts, while it decreases with more bolts in the second stage due to the severe incompleteness of GFRP plates. The failure patterns of the hybrid joints mainly include the slippage between connected plates, the compressive failure and shear failure of GFRP material, and the inclination of bolts. A proper arrangement of bolts can lead to shear failure of GFRP which makes full use of the material property. The final failure loads of four-bolt and nine-bolt joints are respectively 14.5 % and 22.9 % higher than the single-bolt specimen. As the plate thickness getting greater, the shear bearing capacity of hybrid joint increases almost linearly, while it would increase first and then descend with increasing bolt edge distance. In general, the achievement of this work can provide references for the design and further study of the GFRP hybrid joints.