Shape Of Opening Research Articles

Effects of openings on postbuckling behavior of large‐size composite C‐beam under bending‐shear coupling load

AbstractProper design and accurate mechanical assessment of composite C‐beam after opening are of great importance in structure engineering. This paper aims to experimentally and analytically investigate the postbuckling response of large‐size C‐beam with web opening under bending‐shear coupling load. New specimen with four different open shapes were designed and tested. Strain gauges and displacement measurements were applied to monitor its buckling behavior, strain field distribution and critical failure load. Four specimens with various openings were loaded until catastrophic failure occurred. Additionally, an analytical model was introduced to predict the residual strength of circular opening. The results indicate that while the presence of an opening significantly decreases the load carrying capacity, it has minimal effect on the bending stiffness. Compared with intact specimen, the initial delamination, buckling and ultimate strength of the circular opening decreases less than those of the rectangular opening. By altering the position of the rectangular opening, improvements can be made in terms of initial delamination resistance and buckling load; however, ultimate strength remains largely unaffected. Reinforcing the edge of an opening further reduces resistance to initial delamination but other two indicators are improved. Overall, from buckling to failure stages, post‐buckling bearing capacity after opening decreases by 40%. Moreover, the shear failure mode is observed during catastrophic failures. And the analysis method employed is relatively conservative.Highlights Ten large size composite C beams are conducted under coupling loads. Deformation, strain distribution and failure mode are presented. Influence of openings on postbuckling behavior of beam is analyzed. An analysis method is employed to predict the residual strength of beam. It could provide valuable insights for assisting in designing beam openings.

Modeling nonlinear stress-strain model for sulfate dry-wet cycle erosion of concrete: considerations for the initial compaction stage

Sulfate dry-wet cycle erosion significantly affects the mechanical properties of concrete. Investigating the uniaxial compressive stress-strain relationship under these conditions is essential for developing accurate constitutive models. This study analyzes the uniaxial stress-strain curves of concrete subjected to dry-wet cycles in 5% and 15% sulfate solutions. The results show that the initial compaction phase in the stress-strain relationship is particularly pronounced under increasing sulfate concentrations and cycle counts. The concrete experiences an extended compaction phase, which accounts for up to 35.71% of the total strain process. This finding challenge traditional constitutive models, which struggle to accurately describe this phase. To address this issue, the study develops a nonlinear stress-strain model for concrete, incorporating the initial damage caused by sulfate dry-wet cycle erosion, based on Weibull statistical damage mechanics principles. The research indicates that the effects of sulfate concentration and cycle count are predominantly reflected in the pronounced nonlinearity of the skeleton strain function’s opening size (a) and shape characteristics (b), modeled using a fourth-degree polynomial. The model demonstrates an excellent fit to experimental data with an R2 value of 0.99989, showing that the proposed nonlinear stress-strain relationship effectively captures the uniaxial mechanical behavior of concrete under sulfate dry-wet cycle erosion and provides a robust framework for developing constitutive models in such environments.

Influence of opening shape, size and position on the ultimate strength, stiffness and energy dissipation of confined brick masonry walls

Influence of opening shape, size and position on the ultimate strength, stiffness and energy dissipation of confined brick masonry walls

Theoretical Substantiation of Methods for Reducing the Near-Side Radiation of Antennas for an Earth Satellite Communication Station

Within the framework of this article, various methods of reducing the lateral radiation of the antenna are considered, which mainly relate to the angular directions directly adjacent to the direction of the main radiation of the antenna for an earth satellite communication station. The relevance of this issue is beyond doubt, since it is the behavior of the antenna's diagrammatic orientation in this area that most significantly determines the electromagnetic compatibility of various satellite communication systems. The presence of axial shading leads to a significant increase in the near side lobes. The specified deformation of directional properties in a certain plane can be eliminated by using an additional radiator, the phase center of which in this plane coincides with the phase center of the antenna. Shadow radiation compensation is carried out only in a beam of regions close to the plane perpendicular to the straight line connecting the centers of the main and auxiliary antennas. The angular compensation area can be significantly expanded if the phase centers of the main and auxiliary antennas are combined. This rather trivial conclusion is still waiting for its non-trivial technical implementation. Wide-angle compensation of lateral radiation is proposed to be carried out by two auxiliary antennas located parallel to the suppression plane. The best results can be obtained by optimizing the opening shape of the auxiliary radiators. Studies show that the optimal variant of the directional pattern occurs when the mentioned irradiators are made in the form of rectangles with a length of 0,295 and a height of 0,117 from the opening radius of the main antenna, and the distribution in the openings of the auxiliary antennas is cosine-shaped. In this case, it is possible to suppress the radiation level to -40 dB.

One-pot fabrication of open-spherical shapes based on the decoration of copper sulfide/poly-O-amino benzenethiol on copper oxide as a promising photocathode for hydrogen generation from the natural source of Red Sea water

Abstract Harnessing green hydrogen production from natural Red Sea water offers an innovative solution to address energy challenges. A one-pot fabrication method is used to create novel nanocomposite thin films with open-spherical shapes, utilizing copper sulfide/poly-O-amino benzenethiol decorated on copper oxide as a promising photocathode. After thorough analysis, a unique morphology characterized by open spherical shapes is projected, which contributes to improved optical absorption. The bandgap of the nanocomposite is 1.17 eV, enabling efficient absorption of light across the entire optical spectrum, extending up to 950 nm. Utilizing Red Sea water as an electrolyte, the generated J ph serves as an indicator of H2 gas production. The substantial J ph value of −0.82 mA cm−2 is achieved at −0.85 V under light illumination. Furthermore, J ph values exhibit variability, starting at −0.58 mA cm−2 (at 730 nm) and increasing to −0.75 mA cm−2 at a wavelength of 340 nm. The estimated hydrogen gas production rate reaches 1.5 µmole h−1 cm−2, translating to an impressive 15 µmole h−1 for every 10 cm². This remarkable rate underscores the effectiveness of the photocathode, especially given its fabrication through a single-step process that is suitable for mass production. In addition, its cost-effectiveness further enhances its appeal as a viable solution for renewable energy production for hydrogen gas generation from seawater.

Impact of Window Opening Shapes on Wind-Driven Cross Ventilation Performance in a Generic Isolated Building: A Simulation Study

Both environmental concerns and sustainable development goals have led to the search for alternative energy-efficient solutions. Natural ventilation, a crucial aspect of energy-efficient building design, reduces dependence on mechanical systems and regulates indoor air quality and temperature using natural forces. It improves indoor air quality, reduces energy consumption, and lowers operating costs. This paper presents a computational fluid dynamics analysis of natural cross-ventilation in an isolated building with varying window opening geometries. u/uref showed a marked decrease in triangular geometries, while trapezoidal and reference geometries exhibited comparable declines. The airflow velocity profile revealed a U-shaped curve, with reductions observed within 0

Optimizing beam performance: ANSYS simulation and ANN-based analysis of CFRP strengthening with various opening shapes

Optimizing beam performance: ANSYS simulation and ANN-based analysis of CFRP strengthening with various opening shapes

A New Small-Aperture Device Implanted on Top of the Intraocular Lens: Safety, Feasibility, and First Clinical Results.

To investigate the feasibility and safety of a new small-aperture device, which is implanted on top of the intraocular lens. Regular cataract surgery was performed in both eyes in 7 patients. In the non-dominant eye, a small-aperture device (VisionXtender; Morcher) was additionally implanted into the capsular bag at the end of the surgery. The mask had an inner diameter of 1.4 mm. Feasibility and safety were investigated 3 months and 2 years after surgery. In all cases, the device was successfully positioned in the capsular bag without any intraoperative complications. No inflammation was observed at the 3-month follow-up visit. All patients achieved binocular uncorrected distance visual acuity of 0 logarithm of the minimum angle of resolution (log-MAR) or better. Additionally, distance-corrected intermediate visual acuity of 0.1 logMAR or better was measured in the non-dominant eye. Two years postoperatively, Nd:YAG capsulotomy was performed in three patients in both eyes. This clinical feasibility trial demonstrates that the use of the new small-aperture device is both easy and safe. No intraoperative or postoperative complications were reported. All patients attained satisfactory distance, intermediate, and near visual acuity. The device shows significant potential when used in combination with different intraocular lenses (eg, toric). In the future, different opening shapes seem to be possible. [J Refract Surg. 2024;40(9):e662-e666.].

A Review on Seismic Performance of Steel Plate Concrete Walls with Openings

Double steel plate concrete combination wall is a new structural form, with reinforced concrete structure does not have the advantages: both sides of the steel plate can be used as a template for concrete pouring, control the width of cracks in the concrete and extension of leakage, to avoid premature collapse, out of the working state, and at the same time can mitigate the hazards of the impact of the flying object to play a protective role; filled with concrete to enhance the stability of the steel plate to avoid the premature bulging of the steel plate. Drumming. Opening holes in the shear wall structure will not only reduce the integrity of the shear wall, but also affect its seismic performance. When faced with different functional requirements, the selected opening design program will also be different, but for the specific hole arrangement method there is no clear provisions given in the code. Therefore, a large number of scholars at home and abroad have carried out research on shear walls with different opening sizes, locations or shapes by means of experiments and simulations to analyze the influence of these factors on shear walls with openings first.

Performance of Composite Steel-Concrete Beam with Stiffener next to Web Opening

Abstract Openings are provided in Composite steel-concrete beams (CB) for the allowance of ducts and pipes, which generally reduces the beam's flexural performance. So, to retain the strength of these beams, stiffeners are introduced adjacent to the web openings. Hence, a numerical study is performed to evaluate the influence of the stiffeners next to web openings through finite element analysis (FEA) software ABAQUS v6.14. Three different shapes of openings with three different placements of stiffeners are considered for the study, namely circular, rectangular, and triangular openings with stiffeners along longitudinal, transverse, and diagonal directions. As revealed from the findings of FEA, comparisons are made based on the ultimate load, stiffness, and stress distribution. From comparisons, it is found that double-sided longitudinal and transverse stiffeners next to the circle opening are comparable to conventional CB. Similarly, Diagonal stiffeners increase strength in rectangular and triangle openings. Transverse stiffeners failed to increase load capacity and decrease stress concentration compared to other longitudinal and diagonal stiffeners. Further validation for the finite element results is done using the Levenberg-Marquardt (LM) algorithm, using the backpropagation variant technique of Artificial Neural Network (ANN). The results of ANN, i.e., Mean Square Error (MSE) and Multiple Determination Coefficient (R2), are above 0.9 and below 1, respectively. Thus, the results of ANN indicate that the provided results are perfectly fit for predicting with the ANN technique.

Characteristics Of Two Original Facades (Gable and Gunungan) Of Malabero Chinese Shop House In Bengkulu City

Building facades convey a period of culture at the time the building was built, as well as providing the identity of a cultural group or community. Building facades and anthropology became the impetus to find out the original characteristics of the two main facades in the row of Malabero Chinese shophouses on Jalan D. I. Panjaitan Bengkulu City. This research uses the field observation method to obtain data through photographs as well as information from the surrounding community, historians, and cultural experts in Bengkulu and Malabero Chinese Village, to get a link to the facade pattern with an emphasis on building facade elements (roof, walls and building openings) through variables of Chinese shophouse facade characteristics and shop house facade indicators. Malabero Bengkulu's Chinese shophouses are grouped within the Chinese settlement (Chinese Kamp) in front of Fort Marlborough, initially having two characteristics of Chinese shophouse building styles based on their facades. The alteration of the south side of the Malabero Chinese shophouses eliminated many of the original characteristics of the original facade of the Malabero Bengkulu Chinese shophouses (gable roof). As a result, many new characteristics of the shophouse facade elements have been replaced. The shape of the roof (gunungan), the removal of the balcony, and the shape of the building openings became the characteristics of the facade face of the south side Malabero Chinese shop house (gunungan roof). This change in the facade is in anticipation of the load being responsive to earthquakes.

Restoration of load capacity and stiffness of continuous steel–concrete composite beams having web openings using externally applied FRP strips

AbstractThe aim of this study is to explore the applicability of externally bonded fiber‐reinforced polymer (FRP) composites to enhance the structural performance of steel–concrete composite beams with web openings in terms of load capacity and stiffness. In order to achieve this aim, the ABAQUS software was used to create a three‐dimensional (3D) non‐linear finite element model (FEM) to simulate the behavior of FRP‐strengthened continuous composite beams with web openings exposed to monotonic loadings. After ascertaining the accuracy of the proposed model's results in successfully predicting failure patterns and load capacities of the experimentally tested specimens available in the literature, the suggested model was used to create a parametric study. The parametric study focused on the impacts of the opening location, opening shapes, and opening area on the failure pattern, load carrying capacity, and stiffness of continuous steel–concrete composite beams. Additionally, strengthening the web openings using different configurations and lengths of FRP strips with and without bolts was investigated. Results showed that the presence of web openings in location 2 exhibited the lowest load capacity of all investigated beams (20.80%–42.50% lower than the control composite beam). Moreover, the continuous composite beams with a circular opening were the best case and gave a higher failure load as compared to the rectangular opening at all locations. Additionally, all the simulated FRP‐strengthened composite beams in the third group demonstrated significant values of load capacities and stiffness among all the analyzed specimens.

Numerical Analysis of Corrugated Castellated Beam with and Without Openings

The construction industry is constantly seeking innovative solutions to optimize the performance and efficiency of structural elements. Castellated beams with corrugated webs have emerged as a promising option in this pursuit. Their unique geometry, including web holes, makes estimating shear load capacity different from traditional beams with solid webs. These beams are becoming increasingly popular in engineering and economics due to their advantages. The openings in the web can take various shapes, as detailed in the research paper, which compares the load versus deflection for castellated beams with rectangular and hexagonal openings, analyzed using the software ABAQUS® CAE. The trapezoidal corrugated web configuration notably augments the beam's resistance to buckling failure and furnishes superior resistance to buckling compared to a plain web beam. Predominant factors impacting the efficacy of castellated-corrugated web beams encompass the overall beam height and the size of the web opening. The study conducts a comparative analysis of the ultimate load-bearing capability of these beams about both plain and corrugated web beams. Moreover, the manuscript advances an original technological proposal entailing the integration of a trapezoidal-shaped web into a castellated beam. The load-bearing capacity of castellated beams with various web opening shapes, such as rectangles and hexagons, was contrasted with that of the I beam. Among these shapes, hexagon web opening TWHC has higher Material savings with an increase of 13 % compared to the I beam. The results detail that the corrugated web rectangular castellated beams have less weight and more strength than the corrugated web hexagon castellated beam.

Axial compression performance of partially encased concrete columns with web opening

The objective of this study is to comprehensively assess the behavior of partially encased concrete (PEC) columns with web openings under axial compression. The primary objectives of this study are to analyze damage patterns and investigate the influence of key parameters, such as concrete strength, opening rate, and opening shape, on the ductility index and ultimate load-carrying capacity. The study employs experimental testing to examine the response of the PEC columns, with a particular focus on the mechanisms of concrete fracture and flange flexing. Notably, the study reveals a significant impact of the opening rate on the bearing capacity, while the effect of opening shape is comparatively minor. Furthermore, computational analyses are conducted to deepen the understanding of structural behavior. The study builds upon existing research to propose a novel method for calculating the bearing capacity of PEC columns with web openings. This method introduces two discount factors to enhance predictive accuracy.

Design and Optimization of Heat Dissipation for a High-Voltage Control Box in Energy Storage Systems

Abstract To address the issue of excessive temperature rises within the field of electronic device cooling, this study adopts a multi-parameter optimization method. The primary objective is to explore and realize the design optimization of the shell structure of the high-voltage control box, aiming to effectively mitigate the temperature rise in internal components and enhance their thermal management efficacy without altering the fan performance, environmental conditions, or spatial layout. Initially, the study employs computational fluid dynamics methods to investigate the heat dissipation characteristics of the high-voltage control box, subsequently verifying the simulation parameters' accuracy through temperature rise tests. Building upon this foundation, the article conducts a thorough analysis of how the position and shape of the box's openings impact the device's temperature rise. The findings suggest that configuring circular openings on the front and rear sides can optimize the heat dissipation effect. Moreover, the SHERPA algorithm was employed to refine the size and distribution of the openings on the outer shell of the high-voltage control box through multi-parameter optimization, yielding locally optimal structural parameters. Post-optimization, the temperature measurement points within the high-voltage control box exhibited a maximum reduction in temperature rise of 27.16%. The pivotal contribution of this methodology is the application of a data-driven decision-making process for the enhancement of conventional heat dissipation designs. This research offers invaluable practical insights and novel perspectives on the optimization of thermal management designs for box-type electronic devices, significantly advancing the field of thermal management technology in electronic devices.

Habitat Enrichment Causes Changes in Fish Behavioural Characteristics: A Case Study of Sparus latus.

To better understand the habitat preferences and behavioural ecology of Sparus latus, we performed an experiment using box-shaped reefs as habitat enrichment materials, allowing us to determine the behavioural strategies and drivers involved in the response to different enrichment structures. The results showed that the first contact time of S. latus was negatively correlated (Pearson's correlation, p < 0.005) with the distribution rate in the artificial reef area. Enrichment structures affected the habitat preferences of S. latus, and there was a significant difference in the average distribution rate between the control and treatment groups (Adonis, p < 0.001). The opening ratio (Adonis, R2 = 0.36) explained the distribution difference of S. latus better than the opening shape (Adonis, R2 = 0.12). In the absence of an enrichment structure, S. latus remained more active during the daytime, exhibiting poor clustering, while in the presence of an enrichment structure, S. latus exhibited clustered movement at night. The opening ratio was negatively correlated with the average interindividual distance (Spearman's correlation, p < 0.01) and showed a significant positive correlation with the average distribution rate in the reef area (Spearman's correlation, p < 0.001), indicating that the reef opening ratio significantly affected the reef-tropism and clustering behaviours of S. latus. The light intensity was negatively correlated with the average distance moved, and the average speed (Spearman's correlation, p < 0.05) was significantly positively correlated with the reef first contact time (Spearman's correlation, p < 0.001), indicating that the light intensity affected the exploration and activity patterns of S. latus. These results provide a research basis for analysing the pattern and process of fish proliferation induced by artificial reef habitats.

The influence of different root canal open access shapes on the use of rotary root canal enlargement

Background/purposeThe success of root canal treatments is influenced by the shape of the access opening and the outcomes of root canal enlargement. The aim of this study was to evaluate the impact of various rotary instruments on the maintenance of the root canal's central alignment post shaping, considering a range of access cavity designs. Materials and methodsUsing digital tooth simulation, 4 sets of 12 teeth underwent traditional (TradAC) or conservative (ConsAC) access cavity preparations. Root canals were enlarged with TruNatomy or ProTaper Ultimate rotary instruments. Canal transportation and centering ratio were separately measured. Statistical analysis was performed using JMP trial 17 software. ResultsThe analysis revealed no significant difference in buccal and lingual canal transportation among different rotary instruments or canal enlargement designs (P > 0.05). TradAC yielded higher centering ratios in MB and ML canals, while ConsAC excelled in the distal canal for the TruNatomy group. Conversely, in the ProTaper Ultimate group, ConsAC demonstrated higher ML canal ratios (P < 0.05). ConclusionTruNatomy maintained superior canal centering with ConsAC, while ProTaper performed better with TradAC.

Highway tunnel crossing fault zones with water-rich highly weathered granite

This study focuses on the Tianshengqiao Tunnel on the Linshuang Expressway in Lincang City, Yunnan Province, China. By combining the transient electromagnetic method, and geological radar geophysical exploration methods, joint fissures and water abundance in the surrounding rock of the tunnel were predicted. Simultaneously, combined with engineering disasters, such as water inrush and seepage in the surrounding rock during engineering practice, a numerical calculation model for the grouting reinforcement of granite mixed-rock tunnels considering the construction process was established using finite element software. The results indicated that the joint fissures in the tunnel were well-developed and exhibited a disorderly trend, showing an open shape. Accompanied by high humidity in the excavated rock mass, the overall water outflow is mainly as strands, with a large amount of water outflow, especially at the arch crown or left arch waist. The difference in the settlement values of the surrounding rocks at different depths within the grouting circle of the tunnel was relatively small, whereas that outside the grouting circle was significant. The larger the scope of the tunnel grouting circle, the smaller the overall deformation of the surrounding rock after the closure of the tunnel support structure.

UNDAMPED FORCED VIBRATION ANALYSIS OF CASTELLATED STEEL BEAM WITH CIRCULAR, SQUARE AND PENTAGONAL WEB OPENINGS

This study conducts a comprehensive investigation into the influence of web opening shapes on the forced vibration response of castellated steel beams, particularly emphasizing the temporal aspects of the dynamics. These beams are widely employed in practice due to their enhanced structural efficiency and reduced weight, but the incorporation of web openings may potentially impair their shear and bending strength capacities. Three types of web opening shapes are considered. Finite element methodology is employed using ANSYS. The investigation encompasses the forced vibration behavior of castellated steel beams subjected to varying loads. Additionally, the impact of various parameters, including the beam’s geometry, and boundary conditions, on the dynamic behavior of castellated beams are analyzed. The obtained results demonstrate that the web opening shape has significant influence on the vibration amplitudes and oscillation periods of castellated steel beams.

Influence of deflectors on indoor airflow velocity distribution under natural ventilation conditions

Deflectors offer a cost-effective solution for enhancing airflow distribution. The purpose of this paper is to investigate the effect of the deflector on the indoor airflow velocity distribution under natural ventilation conditions. The results obtained from numerical simulations are validated through experimental measurements using a reduced-scale model. Subsequently, the validated reduced-scale numerical model was extended to full-size rooms. A full-size numerical simulation method is used to analyze the effect of no deflector, deflectors with different opening width-to-height ratios and deflectors with different opening shapes on the percentage of indoor velocity partitions under natural ventilation conditions. The findings reveal that the judicious installation of deflectors can enhance indoor airflow velocity distribution and increase the percentage of the indoor comfort zone. Deflectors with different opening width-to-height ratios exert distinct influences on indoor airflow velocity distribution. When the deflector opening width-to-height ratio is set at 7/6, the indoor comfort zone percentage reaches its maximum at 75.98%. Furthermore, the shape of the deflector’s opening significantly affects indoor airflow velocity distribution, and when the opening shape is a rhombus shape of 4.00 cm × 9.00 cm, the proportion of indoor velocity comfort zone is the largest, which is 75.56%. This study provides a reference for the design and practice of natural ventilation in buildings.