3D Effects Research Articles

A fundamental study on 3D effects of irregular ground on seismic ground motions based on observation records and FEM analyses

A fundamental study on 3D effects of irregular ground on seismic ground motions based on observation records and FEM analyses

Twelve Times Faster yet Accurate: A New State‐Of‐The‐Art in Radiation Schemes via Performance and Spectral Optimization

AbstractRadiation schemes are critical components of Earth system models that need to be both efficient and accurate. Despite the use of approximations such as 1D radiative transfer, radiation can account for a large share of the runtime of expensive climate simulations. Here we seek a new state‐of‐the‐art in speed and accuracy by combining code optimization with improved algorithms. To fully benefit from new spectrally reduced gas optics schemes, we restructure code to avoid short vectorized loops where possible by collapsing the spectral and vertical dimensions. Our main focus is the ecRad radiation scheme, where this requires batching of adjacent cloudy layers, trading some simplicity for improved vectorization and instruction‐level parallelism. When combined with common optimization techniques for serial code and porting widely used two‐stream kernels fully to single precision, we find that ecRad with the TripleClouds solver becomes 12 times faster than the operational radiation scheme in ECMWF's Integrated Forecast System (IFS) cycle 47r3, which uses a less accurate gas optics model (RRMTG) and a more noisy solver (McICA). After applying the spectral reduction and extensive optimizations to the more sophisticated SPARTACUS solver, we find that it’s 2.5 times faster than IFS cy47r3 radiation, making cloud 3D radiative effects affordable to compute in large‐scale models. The code optimization itself gave a threefold speedup for both solvers. While SPARTACUS is still under development, preliminary experiments show slightly improved medium‐range forecasts of 2‐m temperature in the tropics, and in year‐long coupled atmosphere‐ocean simulations the 3D effects warm the surface substantially.

Rapid aerodynamic method for predicting the performance of interacting wing sails

Rapid performance prediction tools are required for the evaluation, optimization, and comparison of different wind propulsion systems (WPSs). These tools should capture viscous aerodynamic flow effects in 3D, particularly the maximum propulsion force, stall angles, and interaction effects between the lift-generating units. This paper presents a rapid aerodynamic calculation method for wing sails that combines a semi-empirical lifting line model with a potential flow-based interaction model to account for 3D interaction effects. The method was applied to a WPS that consisted of several wing sails with considerable interaction effects. The results were compared to CFD RANS simulations in 2D and in 3D. For the evaluated validation cases, the interaction model improved the prediction considerably compared to when the interaction was not accounted for. The method provided acceptable driving force, moments, and stall predictions, with negligible computational cost compared to 3D CFD simulations.

Down to the bone: a pilot study into the effectiveness of 3D versus 2D learning in anatomy education.

Possessing excellent anatomical knowledge is crucial for every health care trainee, including medical and physiotherapy students. Hands-on sessions in the dissection class form the cornerstone of anatomy education. Recent years increasing student numbers and decreased availability of time within the anatomy dissection room, forces the development of alternative teaching methods to use the dissection class as efficiently as possible. Most alternatives include video recordings and books (2D), but also 3D high-fidelity models (3D-HFM). These are anatomically accurate, morphable and dynamic 3D models that result from scanning cadaveric specimens. It is assumed that 3D-HFM have some learning benefits over 2D-models. Development of 3D-HFM is a cost- and time-consuming task and the effect of 3D learning into anatomy education needs to be further evaluated before it can be properly integrated into the program. Therefore, a pilot study is set-up to investigate the learning effect of manipulable 3D-HFM.
 The pilot study focuses on the effect of using static 2D atlas-type models (2D-ATM) versus manipulable 3D-HFM on learning processes and outcomes when studying and preparing for hands-on osteology of the skull in first-year physical therapy students. 10 students will be randomly assigned into 2 groups (n=5). Students will be invited one-by-one to the Antwerp Social Lab. After having measured their prior anatomy knowledge and spatial ability, students will watch a knowledge clip explaining the basics of the skull. Then, depending on the condition, students are given either static 2D-ATM or manipulable 3D-HFM to study (as if for an exam) the osteology. While learning, students’ eye movements and electroencephalography (EEG) are collected to capture students’ cognitive load. Log data of their actual manipulation of the 2D-ATM or 3D-HFM is collected as well. When finished, students are given a post-test that maps their anatomical knowledge about the osteology of the skull using (1) nominal questions on pictures and x-rays, and (2) more complex questions capturing students’ insight. Finally, a practical test on a physical skull bone is administered that requires students to recognize certain structures and underlying relationships. 
 
 This pilot will form the basis of a broader research into innovation in anatomy education. Further research is needed to investigate to what extent online 3D-HFM are appropriate to improve the learning process and outcome compared to 2D-ATM. These studies should also examine the effect of 3D-HFM can compensate for the decreased time spent in the dissection room.

Dynamic behaviors and bolt-strengthening effect of sand-powder 3D printing rock analog under static and dynamic coupled loading

In deep mining, surrounding rock mass are subjected to high in-situ stress and dynamic loading, which leads to the difficulties in maintaining the roadway stability. Therefore, it is important to investigate the mechanical characteristics of rock bolts and their ability to enhance stability when exposed to static and dynamic coupled loading (SDCL). 3D printing technology can effectively address the challenges of preparing weak rock specimens and overcoming high variability. Consequently, the Split Hopkinson pressure bar (SHPB) is used to conduct SDCL testing on 3D printing specimens with varying bolted lengths. The similarity in mechanical performance between sand-powder 3D printed specimens and natural coal specimens has been validated. The rock dynamic characteristics with different bolted lengths under SDCL of specimens were explored. The macroscopic fragmentation and microscopic electron microscope scanning were used to reveal the dynamic failure characteristics of specimens. The study shows that static, dynamic and combined strength are positively correlated with bolted length. The dynamic strength is negatively correlated with the axial stress, and the combined strength initially increases and then subsequently decreases as the axial stress increases. The dynamic strength and the combined strength are positively correlated with the impact pressure. Efficient prevention of specimen fracture was achieved by increasing the length of the bolted connection. It can be found that at the meso-scale, when the specimen is only under the static loads, the cross-section particles are fractured along particle bonding, and under the SDCL, there are fractured along particle bonding and fractured through particle. The conclusions obtained can offer a foundation for conducting dynamic rock mechanics experiments using sand-powder 3D printed specimens and for controlling the surrounding rock in dynamic pressure roadways.

Analysis of the interaction between bolt-reinforced rock and surface support in tunnels based on convergence-confinement method

To investigate the interaction of the bolt-reinforced rock and the surface support, an analytical model of the convergence-confinement type is proposed, considering the sequential installation of the fully grouted rockbolts and the surface support. The rock mass is assumed to be elastic-brittle-plastic material, obeying the linear Mohr-Coulomb criterion or the non-linear Hoek-Brown criterion. According to the strain states of the tunnel wall at bolt and surface support installation and the relative magnitude between the bolt length and the plastic depth during the whole process, six cases are categorized upon solving the problem. Each case is divided into three stages due to the different effects of the active rockbolts and the passive surface support. The fictitious pressure is introduced to quantify the three-dimensional (3D) effect of the tunnel face, and thus, the actual physical location along the tunnel axis of the analytical section can be considered. By using the bolt-rock strain compatibility and the rock-surface support displacement compatibility conditions, the solutions of longitudinal tunnel displacement and the reaction pressure of surface support along the tunnel axis are obtained. The proposed analytical solutions are validated by a series of 3D numerical simulations. Extensive parametric studies are conducted to examine the effect of the typical parameters of rockbolts and surface support on the tunnel displacement and the reaction pressure of the surface support under different rock conditions. The results show that the rockbolts are more effective in controlling the tunnel displacement than the surface support, which should be installed as soon as possible with a suitable length. For tunnels excavated in weak rocks or with restricted displacement control requirements, the surface support should also be installed or closed timely with a certain stiffness. The proposed method provides a convenient alternative approach for the optimization of rockbolts and surface support at the preliminary stage of tunnel design.

3D effects on hydrogen transport in ITER-like monoblocks

The influence of recombination on the poloidal gaps of ITER-like monoblocks on hydrogen transport simulations is investigated. A 3D FESTIM model is first built and transient simulations up to 1×107 s of continuous exposure are run with or without instantaneous recombination on the poloidal gaps. In the case of instantaneous recombination, the poloidal gaps act as a strong sink for hydrogen leading to a decrease in the monoblock inventory. The total desorption flux on the poloidal gap is greater than on the toroidal gap but remains orders of magnitude lower than the retro-desorbed flux at the top surface. For a monoblock thickness of 4 mm, the relative difference in the hydrogen inventory per unit thickness between the two cases is 500%. As the thickness of the monoblock increases, this difference decreases (55% at 14 mm). The monoblock’s response to baking is then studied at different baking temperatures. At 600 K, almost all the hydrogen content in the monoblock is removed after 15 days of baking. Assuming a non-instantaneous recombination on the tungsten surfaces would not have a major impact on the monoblock desorption for baking temperatures above 600 K.

Longitudinal Dynamic Response of a Large-Diameter-Bored Pile Considering the Bottom Sediment and Radial Unloading of the Surrounding Soil

The longitudinal dynamic response of a large-diameter-bored pile is investigated considering the bottom sediment and the radial unloading of the surrounding soil. First, the sediment between the pile tip and the bedrock is treated as a fictitious soil pile with a cross-sectional area similarto that of the pile tip. The large-diameter-bored pile (including the fictitious soil pile) is considered as a Rayleigh–Love rod and is divided into finite segments. Under theseconditions, the three-dimensional (3D) effect of the wave propagation along the pile is indirectly simulated by considering the transverse inertia of the pile to avoid complicated calculations. Meanwhile, the surrounding soil is divided into finite annular zones in the radial direction, with the soil properties varying radially as well to simulate the radial unloading of the surrounding soil during construction. The governing equation for each soil zone is built and solved, from zone to zone, to obtain the shear stress acting on the pile. Then, the governing equation for the fictitious soil pile (i.e., the sediment) is solved to derive the dynamic action at the pile tip. In a similar manner to that ofthe fictitious soil pile and together with the recursion method, the governing equation for the pile is solved to obtain the pile’s complex impedance and velocity response. The proposed solution is verified and then introduced to portray the coupling effect of the sediment, pile parameters and radial unloading of the surrounding soil on the longitudinal dynamic response of the large-diameter-bored pile.

3D dual network effect of alkalinized MXene and hBN in PVA for wearable strain/pressure sensor applications

Next-generation wearable electronic devices rely on electronic skin for its high flexibility, wearability, and ability to monitor vital health signs. Despite these advantages, developing flexible strain sensors for full-range human activity detection remains challenging. A solution involves thread-based motion sensors seamlessly integrated into clothing. This study employs a synergistic dual three-dimensional network using hydroxyl-functionalized MXene (MXOH) and hexagonal boron nitride (hBN) to modify poly(vinyl alcohol) (PVA) hydrogels, showcasing promising advancements in wearable technology. The hydrogel, incorporating MXOH with its larger lateral size and hBN with its smaller lateral size, forms a robust 3D network that reinforces the percolation network of MXOH nanosheets. This strategic combination ensures stability in the conductive pathway, minimizing electrical hysteresis during mechanical stress. The completion of the 3D network in PVA, facilitated by hBN, significantly enhances electrical conductivity due to the ion conduction properties of hBN. Moreover, the incorporation of non-conductive hBN nanosheets amplifies overall conductivity compared to MXOH alone, contributing to network stability. Rheological tests demonstrate the pronounced impact of increasing hBN weight percentage on the storage modulus, indicating the formation of a 3D network upon percolation. Additionally, MXOH and hBN exhibit self-healing characteristics through hydrogen bonding with the PVA chain, with hBN displaying higher mobility and faster self-healing compared to MXOH. These hydrogel-based flexible sensors exhibit mechanical stability and responsiveness across a wide pressure range (0 to 80 kPa) and find versatile applications in touch screens, thread-based motion sensors, and wearable electronics, promising transformative advances in handwriting-to-digital translation and smart textile technologies.

Development of inverse static model of continuum robots based on absolute nodal coordinates formulation for large deformation applications

AbstractContinuum robotics has emerged as a prominent trend within the robotics field for about two decades. Nevertheless, motion analysis of continuum robots based on dynamic modelling remains severely limited. In the realm of continuum robots, it is obvious that simplified theoretical models or first-order approximations utilizing springs and dampers are insufficient for capturing the dynamics of soft-bodied structures. This inadequacy is especially apparent in applications involving significant deformations in 3D space, continuous actuation, and interface effects. In this regard, the development of precise theoretical models is crucial. Within this particular framework, the paper presents the absolute nodal coordinates formulation (ANCF) to construct the kinematic models of continuum robots. The transformation between the structural, body, and element coordinate systems, as well as the derivation of the generalized external forces and moments using the principle of virtual work and the velocity gradient tensor, are demonstrated. Additionally, it proceeds to develop the strain measures required for the computation of the elastic forces of elements with circular cross sections, ultimately enabling the construction of the Forward Static Model (FSM) of continuum robots. A procedure based on B-spline surface geometry is proposed to figure out the robot shapes in space and generate the necessary nodal coordinates and gradients of ANCF elements. Finally, the inverse static model (ISM) of the ANCF-B-spline generated structure is presented using an iterative solution approach. The effectiveness of the proposed model is evaluated by the analysis of numerical examples. According to the numerical results, it can be inferred that the ANCF method well captures the modelling aspects of continuum robots. The results obtained from the FSM demonstrate a high level of accuracy, moreover, the driving forces based on the ISM provide, from a practical standpoint, satisfactory results.

Skeletal and Dentoalveolar Changes in Growing Patients Treated with Rapid Maxillary Expansion Measured in 3D Cone-Beam Computed Tomography.

The skeletal and dental effects of rapid maxillary expansion (RME) have been extensively studied, but high-quality research is still needed to determine the three-dimensional (3D) effects of RME. The aim of this study was to compare skeletal and dentoalveolar parameters through cone-beam computed tomography (CBCT) pre- (T1) and post-treatment (T2) with respect to RME. Twenty growing patients (mean age 10.7 years) were treated with a Hyrax-type expander. A 3D CBCT was performed at T1 and T2, measuring nasal width, maxillary width, palatal height, maxillary arch perimeter, angulation of the upper first molar, and intermolar width. The mean palatal suture opening was 2.85 ± 0.62 mm (p < 0.0001). Nasal width increased 1.28 ± 0.64 mm and maxillary width 2.79 ± 1.48 mm (p < 0.0001). In contrast, palatal height was reduced 0.65 ± 0.64 mm (p < 0.0001). Regarding arch perimeter, the radicular perimeter increased 2.89 ± 1.80 mm, while the coronal perimeter increased 3.42 ± 2.09 mm (p < 0.0001). Molar angulation increased 5.62 ± 3.20° for the right molar and 4.74 ± 2.22° for the left molar (p < 0.0001). Intermolar width increased 5.21 ± 1.55 mm (p < 0.0001). Treatment with Hyrax produced a significant opening in the mean palatal suture. Also, a significant increase in nasal width, maxillary width, arch perimeter, molar angulation, and intermolar width, and a decrease in palatal height, were observed.

Embossing Volume 3D Effect by Using DCRA Plate

Embossing Volume 3D Effect by Using DCRA Plate

3D quantum Hall effect in a topological nodal-ring semimetal

A quantized Hall conductance (not conductivity) in three dimensions has been searched for more than 30 years. Here we explore it in 3D topological nodal-ring semimetals, by employing a minimal model describing the essential physics. In particular, the bulk topology can be captured by a momentum-dependent winding number, which confines the drumhead surface states in a specific momentum region. This confinement leads to a surface quantum Hall conductance in a specific energy window in this 3D system. The winding number for the drumhead surface states and Chern number for their quantum Hall effect form a two-fold topological hierarchy. We demonstrate the one-to-one correspondence between the momentum-dependent winding number and wavefunction of the drumhead surface states. More importantly, we stress that breaking chiral symmetry is necessary for the quantum Hall effect of the drumhead surface states. The analytic theory can be verified numerically by the Kubo formula for the Hall conductance. We propose an experimental setup to distinguish the surface and bulk quantum Hall effects. The theory will be useful for ongoing explorations on nodal-ring semimetals.

Boundary Element Method Analysis of 3D Effects and Free-Surface Proximity on Hydrofoil Lift and Drag Coefficients in Varied Operating Conditions

_ The use of hydrofoils to enhance ship performance raises the scientific issue of free-surface proximity, which is important to consider during the design stage, to feed velocity prediction programs, for instance. Typically, the flow over a shallowly submerged hydrofoil is characterized by the Froude number, the submergence depth-to-chord ratio, the angle of attack, and geometric parameters of the lifting surface. Among these parameters, the present paper investigates the influence of the wing aspect ratio on the lift and drag coefficients of hydrofoils operating near a free surface. For this purpose, rectangular wings with an H105 profile at 2° angle of attack and aspect ratios ranging from 4 to 20 are systematically analyzed using a 3D boundary element method. The free surface is modeled using a linearized Neumann-Kelvin boundary condition. Chord-based Froude numbers of 0.5, 1.1, and 6.3 are studied. The submersion depth is swept between 0.1 and 30 times the foil chord length. The evolution of the normalized lift and drag coefficients with respect to the foil submersion and the aspect ratio is discussed in detail. Flow velocity is shown to play a significant role in the evolution of the lift and drag coefficients with submersion depth, close to the free surface, for all the aspect ratios. Its influence gets reduced by moving away from the free surface. The critical submersion depth, where the free-surface effects cease, is found to increase with higher flow velocity and aspect ratio. Furthermore, both positive and negative correlations between the force coefficients and the aspect ratio are identified, depending on the operating conditions. It is found that when the proximity to the free surface either enhances or impairs a force coefficient relative to its value in unbounded flow, increasing the aspect ratio amplifies this effect. Overall, this study confirms the effectiveness of steady boundary element methods for simulating the flow around hydrofoil wings in the vicinity of a free surface and contributes to further understanding the influence of geometric parameters on hydrofoil performance. Keywords hydrofoil; free surface; aspect ratio; potential flow; boundary element method (BEM)

Comparison of colourimetric results obtained by spherical and spectrophotometer with directional geometry on samples with extreme UV varnish application

It is known that gloss has a significant impact on colour measurement. The UV varnish used for surface finishing, spot effects, as well as special effects, such as 3D effects and formation of Braille, has a pronounced gloss effect. In this work, a comparison of the spectrophotometer measurement geometry influence on the colour measurement of an unprinted PVC sample covered with UV varnish was done. UV varnish was applied successively in layers, and patches with different number of varnish layers, from 1 to 12, were formed. Two spectrophotometers with different measurement geometries were used for the measurement: Konica Minolta CM-2600d with d/8 measurement geometry, with spectral reflection included and excluded, and different measurement aperture 3 and 8 mm, and X-Rite eXact with 45/0 measurement geometry. By comparing the measurements, it was estab-lished that there is a significant difference in the measured values between different measuring device geometries on the given samples, and that the number of UV varnish layers has a significant influence on this differenc

3D Inversion of Transient Electromagnetic Data for Concealed Karst Cavern Detection

The karst cavern is common undesirable geological body in limestone areas, which can bring great safety hazards to the construction and operation of tunnels, bridges and highways. Transient electromagnetic method (TEM) can effectively detect hidden karst structures based on the difference in electrical property between the karst cavern and the surroundings. Traditionally, 1D inversion is commonly used for the interpretation of TEM data due to its high efficiency. However, this may lead to artifacts due to 2D or 3D effects in practical surveys. In this study, we present a Gaussian-Newton approach to 3D inversion of TEM data for karst cavern detection. The numerical test on synthetic TEM data demonstrates that 3D inversion can effectively delineate the location and geometry of concealed karst cavern compared to the 1D inversion results.

Digital Inheritance of Traditional Mongolian Robes of the Nayman Tribe

Abstract The Mongolian robe is the crystallisation of the wisdom of Mongolian people after a long period of social practice and one of the intangible cultural heritages of humanity. With the gradual disappearance of the nomadic lifestyle in the steppe, it is not easy to protect and pass on traditional Mongolian dress culture and traditional handicraft technology. This study used the digital twin concept to construct a digital twin to try on clothes for a model in a virtual environment, to realise a mirror image presentation of the target physical entity, and to use effective modern technology to protect and pass on the traditional clothing. The experiment used an AlphaM4 3D body scanner to obtain a 3D human body model, as well as reverse engineering technology to process the initial data, such as noise reduction, streamlining, hole patching and smoothing to build a personalised human body model. The traditional black cotton robe of the Nayman tribe researched in the field was mapped by the planar structure design method, and its structure and 2D samples were recovered. A 3D model of the traditional cotton robe of the Nayman tribe was established based on 3D simulation technology to achieve a 3D virtual display effect, enable better dissemination and inheritance, and give a new vitality to non-heritage clothing in the digital era. The research results can provide fresh ideas and technical support for the digital estate and development of other traditional costumes, as well as contribute to the construction of digital resources for intangible cultural heritage.

Experimental and numerical investigation on hydrodynamic performance of a 3D land-fixed OWC wave energy converter

The hydrodynamic performance of a land-fixed oscillating water column (OWC) wave energy device was thoroughly investigated under various wave conditions and geometric parameters through both experimental and numerical studies in a three-dimensional (3D) wave tank. The study involved the measurement and comparison of water surface elevation, air pressure in the OWC chamber, and hydrodynamic efficiency with the results obtained from the 3D Higher-Order Boundary Element Method (HOBEM). The influences of 3D effects, incident wave amplitude, front wall draught, and incident wave angle on the hydrodynamic performance of the OWC device were analyzed. The results demonstrate that, under actual sea conditions, the 3D effects significantly affect the hydrodynamic efficiency of the OWC, making it exceed unity near the resonance frequency. On the other hand, the incident wave angle was found to have minimal effect on the resonant frequency and varied trend of efficiency. However, the hydrodynamic efficiency decreases with increasing incident wave angle. These results highlight the importance of the consideration of the 3D effects and incident wave angles in optimizing the design and performance of fixed OWC wave energy devices.

Gate-readout and a 3D rectification effect for giant responsivity enhancement of asymmetric dual-grating-gate plasmonic terahertz detectors

Abstract We experimentally investigated the asymmetric dual-grating-gate plasmonic terahertz (THz) detector based on an InGaAs-channel high-electron-mobility transistor (HEMT) in the gate-readout configuration. Throughout the THz pulse detection measurement on the fabricated device, we discovered a new detection mechanism called the “3D rectification effect” at the positive gate bias application, which is a cooperative effect of the plasmonic nonlinearities in the channel with the diode nonlinearity in the heterobarrier between the InGaAs channel layer and the InAlAs spacer/carrier-supply/barrier layers, resulting in a giant enhancement of the detector responsivity. We also found that an undesired long-tail waveform observed on the temporal pulse photoresponse of the device is due to trapping of carriers to the donor levels in the silicon δ-doped carrier-supply layer when they tunnel through the barrier to the gate and can be eliminated completely by introducing the so-called inverted-HEMT structure. The internal current responsivity and noise-equivalent power are estimated to be 0.49 A/W (with the equivalent voltage responsivity of 4.9 kV/W with a high output impedance of 10 kΩ) and 196 pW/√Hz at 0.8 THz. These results pave the way towards the application of the plasmonic THz detectors to beyond-5G THz wireless communication systems.

3D Modeling and Design Effect Optimization of Ceramics Using Virtual Reality

3D Modeling and Design Effect Optimization of Ceramics Using Virtual Reality