Hole In Plate Research Articles

Advancing structural integrity prediction with optimized neural network and vibration analysis

ABSTRACT Detecting and locating damage is a crucial endeavor within the field of structural integrity. While Artificial Neural Networks (ANNs) have shown promise in this regard, they have certain limitations that can be overcome through modifications in terms of their structural design and training methodologies. In this study, we propose a new optimization approach, specifically leveraging the Grasshopper Optimization Algorithm (GOA), to enhance the performance of ANNs for predicting multiple damages represented by holes in the aluminum plate. Input parameters are derived from natural frequencies, while hole locations serve as outputs. We utilize a Finite Element Model (FEM) to generate data through simulation, varying hole locations for comprehensive analysis. To authenticate our method, we gather experimental data from vibration analyses of damaged plates spanning various hole locations. A comparative analysis is conducted of proposed algorithm by evaluating its performance against two established metaheuristic algorithms: the Genetic Algorithm (GA) and Ant Colony Optimization (ACO). This comparison was performed to assess the relative effectiveness of our approach. Our novel approach demonstrates superior performance in damage forecasting, offering promising prospects for structural integrity applications.

Experimental study on shear performance of perfobond steel plate in ultra-high performance concrete (UHPC)-normal concrete (NC) connection

Ultra-high performance concrete (UHPC) is an innovative material owing to its merits of high strength, ductility, durability, and chloride corrosion resistance. Considering that the UHPC is expensive, UHPC is usually adopted as the composite material combined with normal concrete (NC). However, good shear bond should be ensured between UHPC and NC. To improve the interfacial performance, a novel perfobond connector was proposed and to be embedded at UHPC-NC interface. A total of 20 push-out specimens with four varying parameters were tested and two failure modes were observed in the specimens, namely cracking and separation. The mechanical properties of peak load and initial stiffness were summarized and analyzed. Analytical studies showed that the shear capacity is primarily provided by the bond (approximately 75 %). Although the dowel had little influence on shear resistance, it can substantially increase the initial stiffness up to 795 % compared to the specimens without hole in the steel plate. Finally, a unified equation for predicting shear capacity of concrete dowel and interfacial bond were derived, which agreed well with the experimental results.

Biomechanical testing of a computationally optimized far cortical locking plate versus traditional implants for distal femur fracture repair

BackgroundThis study experimentally validated a computationally optimized screw number and screw distribution far cortical locking distal femur fracture plate and compared the results to traditional implants. Methods24 artificial femurs were osteotomized with a 10 mm fracture gap 60 mm proximal to the intercondylar notch. Three fixation constructs were used. (i) Standard locking plates secured with three far cortical locking screws inserted according to a previously optimized distribution in the femur shaft (n = 8). (ii) Standard locking plates secured with four standard locking screws inserted in alternating plate holes in the femur shaft (n = 8). (iii) Retrograde intramedullary nail secured proximally with one anterior-posterior screw and distally with two oblique screws (n = 8). Axial hip forces (700 and 2800 N) were applied while measuring axial interfragmentary motion, shear interfragmentary motion, and overall stiffness. FindingsExperimental far cortical locking plate results compared well to published computational findings. Far cortical locking femurs contained the highest axial motion within the potential ideal range of 0.2–1 mm and a sheer-to-axial motion ratio < 1.6 at toe-touch weight-bearing (700 N). At full weight-bearing (2800 N), Standard locking-plated femurs had the only axial motion within 0.2–1 mm but had an excess shear-to-axial motion ratio. Nail-implanted femurs underperformed at both forces. InterpretationFor toe-touch weight-bearing, the far cortical locking construct provided optimal biomechanics to allow moderate motion, which has been suggested to encourage early callus formation. Conversely, at full weight-bearing, the standard locking construct offered the biomechanical advantage on fracture motion.

Experimental and numerical investigations on film cooling performance of converging slot holes in plate and turbine conditions

Based on the heat-mass transfer analogy, the Pressure Sensitive Paint (PSP) technique was used to explore the film cooling characteristics of converging slot holes on the plate model and the actual turbine endwall model conditions. Meanwhile, the numerical calculation was also adopted to pursue the flow field details. The width of the converging slot hole exit is a key geometry affecting cooling performance. On the plate model condition, three widths of exit slot Lw (1.7d, 2.3d, 2.9d) were chosen to obtain the optimal exit width. The case with Lw = 2.3d obtained the highest level of adiabatic effectiveness from spanwise and streamwise views. This case operated as a two-dimensional slot and produced a more uniform cooling jet film relative to other cases. Nevertheless, the cooling performance decreased significantly as the converging slot hole width increased to Lw = 2.9d. Then the cooling performance of three patterns of film holes was further investigated in the turbine endwall. Laid-back fan-shaped holes and converging slot holes could improve the film cooling performance effectively compared to the cylindrical holes. Converging slot holes with Lw = 2.3d improved the uniformity of the cooling jet outflow through rows of upstream film holes, and also effectively avoided the phenomenon of coolant blowing away or high-temperature gas entering the film hole, resulting in high film cooling effectiveness performance. Compared to cylindrical holes, the area-averaged adiabatic effectiveness was increased by 216.5 % for the endwall with cylindrical holes with the momentum ratio I = 0.25. Overall, converging slot holes improved cooling performance among all studied film hole configurations.

PREPARATION OF COMPONENTS FOR ORBITAL WELDING OF TITANIUM TUBES WITH TITANIUM CLAD STEEL SIEVE BOTTOM

The article presents the method of preparing the tube sheet of a heat exchanger made of B265 Grade 1 titanium-clad steel with B338 grade 2 titanium tubes allowing for the qualification of the TIG (Tungsten Inert Gas) orbital welding technology. A test plate was made of A516M Grade 485 unalloyed steel clad with B265 Grade 1 titanium using the explosive method. The 300 x 300 mm plate consisted of a layer of 60 mm thick non alloy steel and 5 mm titanium clad. It had 20 holes drilled in a triangular arrangement, into tubes with a diameter of 34.93 mm made of B338 Grade 2 titanium with a thickness of 0.7 mm were welded. In order to obtain mechanical restraint inside the holes in the test plates, the titanium tubes were rolled out. For rolling, a five-roller was used, equipped with a retaining collar which allows the tube to move freely during rolling. The tests carried out showed that the proposed technology for preparing tube – sieve bottom elements allow for the preparation of a test plate for the qualification of welding technology. The test plate made in accordance with the technological assumptions met all the requirements necessary to qualify the technology for welding tubes with tube plates. Both in the case of non-destructive testing and macrographic testing, there were no problems with compliance with the PN-EN ISO 15614-8:2005 standard.

Long term follow up on treatment of hallux sesamoid fracture with temporary first metatarsal joint internal fixation

Fracture of the hallucial sesamoids is a pathology that causes difficulty for surgeons and patients. Because of the low incidence and the fact that up to 64–90 % heal with non-operative management, there is a lack of clear guidance in the literature for the surgical treatment of sesamoid fracture in cases of failure of non-operative management. Here long term follow up of an alternative method of surgical treatment of sesamoid fracture recalcitrant to nonoperative management is presented.32 individuals were treated with temporary surgical immobilisation of the 1st metatarsophalangeal joint using either crossed wires or two orthogonally placed two hole plates. The patients then underwent removal of the construct at 8 weeks post op after confirmation of healing on a CT scan. There was a 94 % union rate. Return to work was 61 days (15–90) return to sport 80 days (64–112) with no immediate complications and no recurrence. At last follow up mean 10 years (4–16) only 2 patients had gone on to asymptomatic non-union and one patient developed arthritis between the sesamoid and the metatarsal head. No patient has required further surgical intervention.This retrospective cohort of patients demonstrate that this method of treatment is a valuable option in the management of sesamoid fracture which does not alter the biomechanics of the foot and has none of the long term complications of sesamoidectomy or partial sesamoidectomy.

A hydrodynamic cavitation prototype reactor evaluation for decreasing cephalexin concentration in aqueous solution

A prototype of a hydrodynamic cavitation reactor was evaluated to determine the effectiveness of this system on the percentage decrease of cephalexin concentration present in an aqueous solution prepared with ultrapure water. The process variables or factors were pH [5 and 9], number of holes in the cavitation plate [5 and 7] and reaction time (30 min and 60 min). The results indicate that the percentage removal of Cephalexin (CFX) and total organic carbon (TOC) depends on the variables studied and the interaction between them. The highest yields were achieved at pH 5, 5 holes in the cavitation plate and 60 min of reaction reaching values of 24.16 % for CFX and 16.8 % for TOC. It was determined that, for the lowest number of holes in the cavitation plate and acid pH, the phenomenon that guides the process is the hydrodynamic cavitation, when increasing the number of holes and therefore decreasing the intensity of cavitation, the pH becomes more relevant and has incidence on the performance of the analyzed process. On the other hand, it was determined that, also in reaction times of 30 min, removal values very close to the maximum values obtained are achieved. The process can be intensified by the simultaneous application of other advanced oxidation processes to increase the effectiveness.

Extra-articular screw placement strategy in Stoppa approach based on three-dimensional reconstruction model

The study aimed to explore an extra-articular screw placement strategy in Stoppa approach. Radiographic data of patients who underwent pelvic computed tomography from January 2016 to June 2017 were imported into Materiaise’s interactive medical image control system software for three-dimensional reconstruction. Superior and lower margins of acetabulum and ipsilateral pelvic brim could be observed simultaneously through inlet-obturator view. A horizontal line from superior acetabular margin intersected pelvic brim at point “A” and another vertical line from lower margin intersected pelvic brim at point “B” were drawn, respectively. Lengths form sacroiliac joint to “A” (a), “A” to “B” (b), and “B” to pubic symphysis (c) were measured. Patients were divided into four groups depending on gender and side difference of measured hemi-pelvis: male left, male right, female left, and female right. Lengths of adjacent holes (d) and spanning different holes (e) of different plates were also measured. Mean lengths of a, b, c in four groups were 40.94 ± 1.85 mm, 40.09 ± 1.93 mm, 41.78 ± 3.62 mm, and 39.77 ± 2.23 mm (P = 0.078); 40.65 ± 1.58 mm, 41.48 ± 1.64 mm, 40.40 ± 1.96 mm, and 40.66 ± 1.70 mm (P = 0.265); 57.03 ± 3.41 mm, 57.51 ± 3.71 mm, 57.84 ± 4.40 mm, and 59.84 ± 4.35 mm (P = 0.165), respectively. Mean d length of different plates was 12.23 mm. Average lengths spanning 1, 2, 3 and 4 holes were 19.33 mm, 31.58 mm, 43.80 mm, and 55.93 mm. Our data showed that zones a and c could be safely inserted three and four screws. Penetration into hip joint could be avoided when vacant 3-hole drilling was conducted in zone b. Fracture line in zone b could serve as a landmark for screw placement.

Analytical solution to stress intensity factors of cracks on both sides of a triangular hole in an infinite plate

This paper presents an analytical solution for determining the stress intensity factors (SIFs) of double-sided cracks emanating from a triangular hole in an infinite plate. A conformal function is introduced, which can be applied to these cracks, and the SIFs are analytically derived using the Muskhelishvili method. By combining the Schwarz-Christoffel integral with the conformal transformation for cracks originating from circular holes, a mapping function for the cracked triangular hole is presented. The accuracy of the SIF at the single right-sided crack of the triangular hole is validated using finite element method (FEM) and compared with existing references. This study investigates the influence of biaxial loading factors and lengths of cracks on SIFs. The SIF of the hole-edge crack is related to the structure from which the crack emanates. This analytical approach provides a reliable solution for calculating SIFs of double-sided cracks emanating from a triangular hole.

Design and Optimization of Air Inlet in Cuttings Incubator

The microclimate environment can be conveniently controlled with accuracy by plant incubators, in which the cuttings propagation method can efficiently enhance seedling production. To ensure air flow evenly throughout the incubator, the scientific design of the air inlet is crucial. This study utilized a computational fluid dynamics (CFD) model to simulate the airflow patterns in a culture layer under different air inlet conditions. Furthermore, the optimal design parameters were determined by way of response surface methodology (RSM) and the Non-dominated Sorting Genetic Algorithm-II (NSGA-II). Adopting the optimal parameters, a prototype was manufactured, and a cuttings experiment was carried out with apple cuttings in the incubator. The results showed that the optimal air inlet radius is 90 mm, the optimal air inlet height is 188 mm, and the optimal uniform flow plate hole diameter is 13 mm. Meanwhile, the apple cuttings were able to root. Therefore, this incubator with optimal parameters can be used for cuttings. The study provides a methodological and theoretical basis for the future optimizing of air inlet parameters and promoting cuttings rooting.

INVESTIGATE OF INFLUENCE PERFORATED PLATE ON DETERMINATION OF TRANSVERSAL PERMEABILITY ON REINFORCED FIBER

Polymeric composite materials can be build in different forms, resulting in different mechanical properties, with numerous industrial applications. Traditionally, they have been largely used in the automotive, naval and aerospace industries. A major concern in polymeric composites manufacture is related with the determination and control of the reinforcement and resin physical properties. They are responsible for the final composite mechanic properties and, if not correct defined, will result in defective composites. Reinforcement permeability is one of these physical properties that, in some cases, are difficult to be kept within the project specification. More specifically, for the case of the transverse permeability, its corrected determination is reported in literature as being considerably more difficult to experiment than the in-plane permeability. The most common experiment for transverse permeability determination is built with a cylindrical mold on which the reinforcement is positioned (and compressed) between two perforated plates. A fluid is forced transversely through the reinforcement, volumetric flow rate and pressure drop are measured, and the Darcy's Law is used to determine the permeability. In this experiment, flow is assumed rectilinear, and the holes of the perforated plates are ignored in the Darcy equation. It is known that size, number e position of these holes may influence the permeability determination, however this problem is not commonly discussed in literature. In this work it is presented a numerical study about the influence of the geometry of the perforated plates on the corrected determination of the reinforcement transverse permeability. The reinforcement region is molded as a porous medium and the two fluid flow (air + resin) is formulated with the Volume of Fluid (VoF) method. GMSH software was used to created and discretize the geometry and OpenFOAM software, more specifically using the interFoam solver, was used to solve the flow problem, determining pressure drop and flow rate inside the mold. Results have shown that correct determination of the transverse permeability is highly dependent on perforate plates geometry.

Numerical simulations of the flow past a perforated plate enclosed by a filament using the Immersed Boundary Method

The influence of the central hole on dynamics of the coupled system including a perforated plate and a filament was numerically investigated using the immersed boundary method (IBM). Dynamics of the system were first investigated across various length ratios of filament to plate Lr and hole sizes Dh at the Reynolds number Re=100. When Dh≤0.1, the IBM was proven to be unusable due to the area leakage brought about by the smoothed approximation of the Dirac delta function. When Dh>0.1, the calculation results were reliable and showed that the key values were not significantly affected by Dh. Compared to a bare plate, the system exhibits a maximum drag reduction of about 30% at Lr=2.0, regardless of Dh. In contrast to a closed system, a hole facilitated a more harmonious filament flap by allowing fluid exchange, thereby preventing local oscillation of the filament. Additionally, the multiple frequency dominant (MFD) mode was observed and its distribution in Lr-Dh space was also presented. Finally, the simulations under various Re were conducted. The effect of Dh on the system drag was still weak regardless of Re. However, the filament motion changed from periodic to chaotic as Re increased.

Multifunctional hybrid plate lattice structure with high energy absorption and excellent sound absorption

Lattice structures are featured by their extraordinary mechanical performances in specific stiffness, specific strength, energy absorption, and sound absorption, etc. The recent trend of multifunctionality in engineering applications has raised new requirements for the integration of their mechanical and acoustic properties. In this paper, a multifunctional hybrid plate lattice structure denoted as SBHP is proposed by hybridizing the traditional body-centered cubic plate (BCCP) and simple cubic plate (SCP) lattice structures, and its acoustic and energy absorption properties are investigated by theoretical modeling, simulation analysis and experimental verification. The effects of hole diameters and plate thicknesses on the sound absorption performance are investigated by impedance matching and system damping state analysis. The results show that the average sound absorption coefficient of SBHP-1 is increased by 24% and 62%, and the normalized half-absorption bandwidth is enlarged by 45% and 89% than those of BCCP and SCP, respectively. Heterogeneous lattice structures constructed by using the synergistic mechanism of strong and weak coupling have a more outstanding broadband sound absorption effect. This work provides an effective approach for the design of multifunctional lightweight structures with excellent broadband sound absorption and high energy absorption.

Generation of meter-scale nanosecond pulsed DBD and the intelligent evaluation based on multi-dimensional feature parameter extraction

This study introduces a novel meter-scale dielectric barrier discharge (m-DBD) reactor designed to generate large-scale, low-temperature nanosecond pulsed discharge plasma. By employing a modularized gas path, this reactor enables a comprehensive analysis of discharge patterns and uniformity using multi-dimensional discharge parameters. Simulation results reveal optimal gas distribution with ten gas holes in the variable plate and a 40 mm slit depth in the main reactor. Besides, a diagnosis method based on electro-acoustic-spectrum-image (E-A-S-I) parameters is developed to evaluate nanosecond pulsed m-DBD discharge states. It is found that the discharge states are closely related to the consistency of segmental discharge currents, the fluctuation of acoustic signals and the distribution of active particles. Machine learning methods are established to realize the diagnosis of m-DBD discharge pattern and uniformity by E-A-S-I parameters, where the optimized BPNN has a best recognition accuracy of 97.5%. Furthermore, leveraging nanosecond pulse power in Ar/m-DBD enables stable 1120 × 70 mm2 discharge, uniformly enhancing hydrophobicity of large-scale materials from a 67° to 122° water contact angle with maximal fluctuations below 7%. The modularized m-DBD reactor and its intelligent analysis based on multi-dimensional parameter provide a crucial foundation for advancing large-scale nanosecond pulsed plasma and their industrial applications.

Theoretical and simulation of central elliptical hole with rectangular plate

A study on design engineering components with slot, notches is very important, because there is a stress increases/failure region area, where the force/stress is concentrating more and more. The elastic stress concentration mainly depends on the mode of loading, materials, and geometry of the design engineering components. The design engineers, academicians, and researchers concentrated and focused on fail-safe design and safe life design. A Plate is considered with different slots, such as circular and elliptical. The main objective of this study is to find out the stress concentration factor in plates with various cutout shapes. This concept is used in design components/structures, for finding the elastic stress concentration. The methods compared are tabulated with their findings. Singularities of the circular hole and elliptical hole in rectangular plates are considered in the present study. The finite Element Method (FEM) was used for fine mesh and ANSYS WORKBENCH software was used for extracting the results and results were validated by analytical or experimental methods.

Photonic Weyl Waveguide and Saddle-Chips-like Modes.

Topological Weyl semimetals are characterized by open Fermi arcs on their terminal surfaces, these materials not only changed accepted concepts of the Fermi loop but also enabled many exotic phenomena, such as one-way propagation. The key prerequisite is that the two terminal surfaces have to be well separated, i.e., the Fermi arcs are not allowed to couple with each other. Thus, their interaction was overlooked before. Here, we consider coupled Fermi arcs and propose a Weyl planar waveguide, wherein we found a saddle-chips-like hybridized guiding mode. The hybridized modes consist of three components: surface waves from the top and bottom surfaces and bulk modes inside the Weyl semimetal. The contribution of these three components to the hybridized mode appears to be z-position-dependent rather than uniform. Beyond the conventional waveguide framework, those non-trivial surface states, with their arc-type band structures, exhibit strong selectivity in propagation direction, providing an excellent platform for waveguides. Compared with the conventional waveguide, the propagation direction of hybridized modes exhibits high z-position-dependency. For example, when the probe plane shifts from the top interface to the bottom interface, the component propagating horizontally becomes dimmer, while the component propagating vertically becomes brighter. Experimentally, we drilled periodic holes in metal plates to sandwich an ideal Weyl meta-crystal and characterize the topological guiding mode. Our study shows the intriguing behaviors of topological photonic waveguides, which could lead to beam manipulation, position sensing, and even 3D information processing on photonic chip. The Weyl waveguide also provides a platform for studying the coupling and the interaction between surface and bulk states.

Multi-Objective Collaborative Optimization of Stiffness and Damping Performance of Acoustic Black Hole Plate

This paper uses embedded Acoustic Black Hole (ABH) on the wallboard for structure lightening and improving the performance in broadband vibration reduction. The distribution and size of multiple ABHs affect the generalized static stiffness (GSS) and the upper limit of the structure's maximum kinetic energy (ULMKE) in practical applications, which express the ability to resist static load and vibration reduction performance, respectively. In this research, the structure's GSS and ULMKE are considered optimization objectives due to the trade-off between them. The method based on the Pareto optimal solution is adopted to optimize the layout and the radii of the ABHs. The Non-dominated Sorting Genetic Algorithm (NSGA-II) is used as the multi-objective optimization algorithm. Two 2D-ABHs embedded in a plate are optimized as numerical examples. The optimization generated several groups of Pareto optimal solutions, providing more feasible solutions for different applications faster. The verification further proved the necessity and the effectiveness of multi-objective optimization.

Vibration and acoustic characteristics of acoustic black hole plates with variable elastic modulus

Acoustic black hole (ABH), as a new wave manipulation technique, shows excellent applications in vibration and noise reduction of structures. Nowadays, most ABHs use materials with a fixed elastic modulus, limiting their low-frequency performance. Herein ABH plates with variable elastic modulus (VM-ABH) is designed, and its vibration and acoustic radiation characteristics are investigated by using numerical analysis. The results show that the vibration response of VM-ABH has a decrease of 5–13.2[Formula: see text]dB relative to that of the uniform texture ABH (UT-ABH) in the frequency range of 10–5000[Formula: see text]Hz, and the degree of energy aggregation is significantly improved. Moreover, the sound pressure level was reduced by 3.6 dB. Meanwhile, by linearly varying the elastic modulus in the center region of the VM-ABH, the effects of gradient index and terminal elastic modulus on the damping characteristics and dynamic response are revealed. The research results provide new objects for the study of vibration and noise reduction of ABH.

Technique for traversing both plate and nail-locking screw holes in nail-plate composite fixation.

Technique for traversing both plate and nail-locking screw holes in nail-plate composite fixation.

Overstrength and plastic rotation of two-segment replaceable link with separated splicing plate

To enhance the seismic performance and post-earthquake reparability of traditional eccentrically braced frame structures, this study proposes a two-segment replaceable links with separated splicing plate: one featuring specimens with standard holes in the separated splicing plate (TSRL1), and the other featuring specimens with slotted holes in the separated splicing plate (TSRL2). Through cyclic loading tests, it was observed that the hysteresis curves of the links exhibited a relatively complete response, characterized by plastic rotations of 0.09 rad and 0.17 rad respectively. The overstrength coefficient ranged from 1.66 to 2.08, indicating commendable performance in terms of both overstrength and plastic deformation capacity. Subsequently, finite element simulations of the link were conducted using ABAQUS. Based on the congruity between simulation and test results, a parametric analysis was performed to determine the optimal seismic performance of the two-segment replaceable links with separated splicing plate by varying the length of the energy dissipation zone and hole type of the bolts.