Solid Web Research Articles

Feminism as a transatlantic bridge to modernity: María de Maeztu’s Residencia de Señoritas and the American International Institute for Girls in Spain (1917–1936)

ABSTRACT At the beginning of the twentieth century a globalization of women's associations, driven mostly by the United States, Great Britain, and France, was instrumental in the Western advancement of gender equality. Modernist feminist authors disseminated and promoted ideas about suffragism, the integration of women in higher education, pacifism, and gender equality along international networks. In this essay I study two women’s academic institutions that contributed to forming a solid transatlantic web of intellectual alliances between Spain and the United States of America: The International Institute for Girls in Spain (headquartered in Boston) and the Residencia de Señoritas (in Madrid). The two institutions exchanged university faculty through pensions, scholarships, and exchanges, modeling transatlantic intellectual alliance for students. This coalition exponentially grew the numbers of Spanish students in university desks and raised the percentages of Americans and Spaniards completing their higher educations in both countries. Under the visionary feminist leadership of María de Maeztu, several cohorts of students became a new, feminist intercontinental network serving as a motor of twentieth-century modernity.

Structural topology optimization for plastic-limit behavior of I-beams, considering various beam-column connections

This work proposes topology optimization for steel I-beams, including consideration of bolted beam-column connections with geometric and material nonlinear analysis. The aim is to assess and compare the topological configurations influenced by different connections, examining their stress distribution and rotational stiffness to illustrate the potential of structural optimization. The bi-directional evolutionary structural optimization (BESO) approach is implemented. Furthermore, several bolted steel beam-column configurations were validated based on experimental tests. Subsequently, a series of finite element models were developed, contributing to a comprehensive understanding of the plastic-limit behavior of I-beams under different loading conditions. The proposed method could potentially use a lesser quantity of material while maintaining the same level of structural performance. The results indicate that the implementation of structural topology optimization on I-beams while considering various beam-column connections, yields structural performance similar to that of solid web configurations, achieved through material reduction.

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.

Optimization of cross-sectional dimensions of castellated beams with hexagonal openings

The object of this study is a castellated beam, in which the web openings have the shape of a regular hexagon. The beam is examined to find optimal cross-sectional dimensions. The optimization task is stated as the task of finding the optimal profile numbers for top and bottom Tees of the beam and the optimal width of the web opening while ensuring the required load-carrying capacity of the beam. Minimization of the volume of the beam material was considered as an optimality criterion. The stated optimization problem was solved using the exhaustive search method. For an assortment of normal I-beams with parallel flanges, castellated beams were obtained with optimal cross-sectional dimensions depending on the steel grade, the beam span, and the magnitude of transverse uniformly distributed load. The optimization calculations proved that it was possible to increase the elastic section modulus of the beam to 35.48...50 % through the use of a castellated web. Castellated beams with optimal cross-sectional dimensions at the same load-carrying capacity are characterized by lower steel consumption (up to 23.19 %) compared to I-beams with a solid web. Analysis of the results has made it possible to devise recommendations for the optimal distribution of material in the cross-sections of such beams. The results are valid only for the assortment of normal I-beam profiles and only for the case of uniformly distributed load acting on the beam when the compressed beam flange is laterally restrained from the bending plane and the beam web has openings in the form of regular hexagons. It is under such conditions that the reported results can be implemented in practice both at the stage of selecting cross-sections of the studied class of structures, and at the development of effective assortments of castellated beams

Theoretical evaluation of tapered composite plate girders subjected to shear loads

The behavior of prismatic composite steel plate girders subjected to shear loads was thoroughly investigated, and different theories were evaluated. However, the behavior of tapered composite plate girders with and without openings has not yet been investigated. Therefore, this paper presents a new method for predicting the ultimate capacity of tapered composite plate girders subjected to shear loads. The shear capacities of tapered composite plate girders with and without web openings were developed based on the classical theory of tension-field action for prismatic composite plate girders. It is assumed that the shear capacity of such girders can be predicted from the steel plate girder and reinforced concrete slab anchored using shear studs. The effect of the composite action on the top flange owing to the shear studs was considered in the derivation of the equations to calculate the shear capacity of the steel plate girders. In addition, the shape and size of the opening were also considered. The proposed method was verified by comparing the results of the shear capacity with experimental results from previous studies. It can be concluded that the proposed method can predict the shear capacities of tapered composite plate girders with solid and open webs with acceptable accuracy.

Shear performance of partially encased composite beams with high-strength steel and UHPC

Various countries across the globe have implemented strategic policies that encourage the development and use of high-performance materials in engineering structures. This study focused on the shear performance of partially encased composite beams with high-strength steel and UHPC (PEHC beams). Seven PEHC beams under simply supported three-point loading conditions were tested to investigate the effect of main parameters such as the shear span-depth ratio, thickness of steel web, types of steel web, and types of stirrups on shear failure modes, crack patterns, load-deflection behavior, and the response of strains. Two failure modes were observed in PEHC beams, involving diagonal compression failure and shear compression failure. As the shear span-depth ratio decreased from 2.0 to 1.5 and 1.0, the shear strength increased significantly by 13.3% and 70.8%, respectively. Test results demonstrated that the increase in the thickness of steel web and the use of steel solid web positively affect the shear strength of PEHC beams, whereas the impact of normal-strength stirrups types proved insignificant. Finally, a theoretical method was proposed to predict the shear strength of PEHC beams by considering the coworking of four mechanisms: the composite truss, the steel web, the stirrups, and the steel fibres. Then the method was validated by the good agreement between the predicted and tested shear strength results, highlighting its applicability in providing accuracy.

Homogenised model of a common perforated steel beam with four types of openings under uniformly distributed lateral loading

Perforated beams generally exhibit larger shear deformation than solid web beams, and their openings complicate structural design modelling in industrial and civil construction. To address these issues, this study introduces a theoretical homogenised method. This method considers four types of openings in a common perforated beam and its shear deformation equivalence to a solid web beam. For the first time, a reduction coefficient of the bending stiffness is obtained using this method, which equates a common perforated beam to a solid web beam. Through regression analysis, this coefficient is simplified into a formula, which streamlines design modelling of structures using common perforated beams.

An experimental study on shear resistance of austenitic and duplex stainless steel plate girders with perforated webs

Stainless steel is increasingly being used in the field of engineering as building construction materials, as it has an inherent ability to resist corrosion, as well as other environmental benefits. When used as plate girders, web perforations are often required to accommodate building services. In the literature, no experimental study has been reported that investigates the shear resistance of austenitic and duplex stainless steel plate girders with perforated webs. This issue is addressed herein. A detailed experimental program is described comprising eight stainless steel plate girders. The plates are austenitic grade EN 1.4301 and duplex grade EN 1.4462, and the depth of web is fixed as 500 mm and 700 mm. For comparison, specimens with perforated webs and solid webs were tested. Prior to shear tests, the distribution of initial geometrical imperfections was determined through three-dimensional (3D) scanning. Finite element (FE) models incorporating the material non-linearity and initial geometric imperfections were then developed. The results of FE models were validated against the experimental results. Using the validated FE models, a parametric study comprising 182 FE models was then undertaken, and variables which were examined included local geometrical imperfections, aspect ratio, end conditions, hole ratio and stainless steel grades. The results suggested that for those members with a hole diameter - web height ratio of 0.6, the shear resistance was reduced by 52% on average due to the web perforation. The design rules given in Eurocodes, American Specification and those design recommendations proposed by Chen et al. (2023) were evaluated.

Characterization of damping in 3D metal printed gear body using parameter optimization

With the rapid development of the global economy and the widespread use of high-speed machinery, vibration and noise pollution is becoming increasingly serious. The increased energy costs, environmental pollution, and carbon emissions have prioritized sustainable development for industry. As an important link of mechanical transmission, the gear transmission vibration and noise adversely affect the physical and mental health of operators and interfere with the normal use of machinery. This paper proposes a new metal 3D printing-made vibration-damping lightweight gear model. The solid gear web is replaced with a lightening hole structure that is expected to ensure rigidity and torsional compliance while controlling the damping effects of the gear web structure. Gears were manufactured from an additive manufacturing material using a metal 3D printing technique. This work advanced an experimental analysis of the dissipation properties of metal printed gear exploiting vibration tests. A gear frequency-sweeping excitation test bench was designed and developed to simulate in-plane excitation to produce a circumferential torsional mode of the specimen. Circumference damping estimates are guided by executing vibration exciter excitation on the setup. The half-power bandwidth and modal fitting methods were arranged and compared, relying on the measured frequency response function (FRF) single-degree-of-freedom (SDOF) approximation.

Flexural strength of steel girders with perforated web and tubular compression flange

Lateral torsional buckling reduces the moment capacity of steel I-girders. To redress this weakening, one approach is to replace the conventional plate flange with a rectangular tube, which has higher lateral stiffness and is thus helpful to resist lateral buckling. At the same time, web openings are introduced to enable services to pass through, but this causes a reduction in strength. Girders with tubular flange plus web openings have not yet been discussed in the literature. In this paper, finite-element method modelling is used to fill this gap, studying different slenderness classifications, as well as parameters such as size of web openings, spacing and location. The results for a solid web are found to be more comparable to the Eurocodes for steel structures than the American Institute of Steel Construction codes, enabling good prediction of the flexural capacity. By introducing web openings, the flexural capacity is reduced by 10–20%, closer to the higher side for openings with large diameters located near the compression flange. Openings with an oval shape have less reduction in strength, whereas the square is unfavourable. Tubular flange girders, even if perforated, provide flexural strength enhancement and a considerable reduction in material compared with plate flange girders. This section also behaves better in relation to carbon dioxide emissions.

Controllable Water-Triggered Degradation of PCL Solution-Blown Nanofibrous Webs Made Possible by Lipase Enzyme Entrapment

Polymers in nanofibrous forms offer new opportunities for achieving triggered polymer degradation, which is important for functional and environmental reasons. The polycaprolactone (PCL) nanofibrous nonwoven polymer webs developed in this work by solution blow spinning with entrapped enzymes were completely, rapidly and controllably degraded when triggered by exposure to water. Lipase (CALB) from Candida antarctica was successfully entrapped in the PCL webs via an enzyme-compatible water-in-oil emulsion in the PCL–chloroform spinning solution with added surfactant. Protein (enzyme) in the nanofibrous webs was detected by Fourier Transform Infrared Spectroscopy (FTIR), while time of flight-secondary ion mass spectroscopy (ToF-SIMS) and laser confocal microscopy indicated that enzymes were immobilized within solid fibers as well as within microbead structures distributed throughout the webs. Degradation studies of CALB-enzyme functionalized solution-blown nonwoven (EFSBN)-PCL webs at 40 °C or ambient temperature showed that EFSBN-PCL webs degraded rapidly when exposed to aqueous pH 8 buffer. Scanning electron microscopy (SEM) images of partially degraded webs showed that thinner fibers disappeared first, thus, controlling fiber dimensions could control degradation rates. Rapid degradation was attributed to the combination of nanofibrous web structure and the distribution of enzymes throughout the webs. CALB immobilized in the solid dry webs exhibited long storage stability at room temperature or when refrigerated, with around 60% catalytic activity being retained after 120 days compared to the initial activity. Dry storage stability at ambient conditions and rapid degradation upon exposure to water demonstrated that EFSBN-PCL could be used as fibers or binders in degradable textile or paper products, as components in packaging, for tissue engineering and for controlled-release drug or controlled-release industrial and consumer product applications.

Protease Immobilization in Solution-Blown Poly(ethylene oxide) Nanofibrous Nonwoven Webs

Enzyme-functionalized solution-blown nonwoven (EFSBN) fibers were produced by a single-step solution blow spinning method that utilizes high-velocity gas to simultaneously extrude the codissolved polymer–solvent–enzyme spinning solution and evaporate solvent at mild conditions to form a nanofibrous web with preserved enzyme activity. A broad concentration range of 0.6–7.4 wt % protein of subtilisin A protease from Bacillus licheniformis was successfully entrapped by poly(ethylene oxide) (PEO) during solution blow spinning nonwoven web production. The presence of enzyme protein in the solid nanofibers was detected by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Time of flight-secondary ion mass spectroscopy and laser confocal microscopy revealed the immobilized enzymes were mainly positioned inside the fibers and homogeneously distributed throughout the webs. Scanning electron microscopy showed that the fiber shape and diameter of PEO nanofibers containing enzymes were irregular compared to PEO-only nanofibers. Residual enzyme activity in the webs was measured by redissolving fibers in buffer and comparing the released enzyme activity to nonimmobilized free enzyme using a casein substrate-based assay. Immobilized protease (1.3% (w/w) protein in solid dry nanofiber webs) retained more than 90% of the free enzyme activity. Protease immobilized in solid nanofiber webs exhibited long storage stability at ambient (∼22 °C) and 4 °C temperature storage conditions, with more than 60% remaining catalytic activity after 300 days compared to the initial activity. Immobilized protease had equally good thermal stability as a stabilized liquid commercial protease, both retaining above 95% of their initial activity after treatment for 12 h at 65 °C. In contrast, the same liquid protease diluted in buffer lost activity within 2 h at that temperature. The nondusting, readily aqueous-soluble EFSBN solid materials are easy to handle and have good storage stability compared to liquid products.

Prediction of the castellated beams deflections

Introduction. Existence of openings in webs of beams reduce their shear rigidity and increase deflections compare with beams of the same dimensions with solid web. Investigation of the castellated beam’s deflections is important, because one of main demands to beams of engineering structures is guarantee of necessary rigidity, i.е. restriction of ratio deflection to length. In the work it was studied deflections of castellated beams with diamond shape, hexagonal, sinusoidal and circular openings, widely used in structural industry.
 
 Materials and methods. Effect of openings on transverse deflections of the castellated steel beams was studied analytically with theory of composite bars, with the finite element method and experimentally on four meters’ double consoled beams under loading with concentrated forces applied at consoles.
 
 Results. Universal analytical relation was obtained which allow reliably evaluate deflections of simply supported beams with various shape of openings under different kind of loading. Analysis of results of calculation of beams by FEM using program complex ANSYS demonstrates satisfactory correspondence to experimental data and to analytical relations.
 
 Conclusions. Obtained with the theory of composite bars analytical dependences for deflections of simply supported beams are applicable for beams with various type of perforation and different kind of loading.

Structural Stability Analysis of Eye of the Yellow Sea, a Large-Span Arched Pedestrian Bridge

To date, scholars’ research on the stability behavior of the arch structure mainly focuses on solid–web section arches, steel tubular truss arches and concrete-filled steel tubular arches, but the stability behavior of the novel spatial grid arch structure, which integrates the characteristics of grid structure and arch structure, is not yet clear. Based on the Eye of the Yellow Sea pedestrian bridge project in Rizhao, China, the stability behavior of this large-span spatial grid arch structure was studied, in this paper, by the project’s structure design team. The project is a glass covered steel arch pedestrian bridge with a span of 177 m, a height of 63.5 m, an elliptical section with a long axis of 18 m, and a short axis of 13.5 m. The elastic and the nonlinear elasto-plastic stability behavior considering different initial geometric imperfections, was analyzed by the ABAQUS finite element model. The buckling modes and the full-range load-displacement curve of the structure were analyzed, and the stress distribution, deformation mode and overall structural performance during the whole loading process were analyzed. The effects of initial imperfections, geometric nonlinearity and material nonlinearity on the ultimate load-carrying capacity of the structure were studied. The stability behavior of large-span spatial grid arch structure was studied in this paper, which provides an important reference for the design and analysis of such structures.

Heterogeneous Social Linked Data Integration and Sharing for Public Transportation

Solid (social linked data) technology has made significant progress in social web applications developed, such as Facebook, Twitter, and Wikipedia. Solid is based on semantic web and RDF (Resource Description Framework) technologies. Solid platforms can provide decentralized authentication, data management, and developer support in the form of libraries and web applications. However, thus far, little research has been conducted on understanding the problems involved in sharing public transportation data through Solid technology. It is challenging to provide personalized and adaptable public transportation services for citizens because the public transportation data originate from different devices and are heterogeneous in nature. A novel approach is proposed in this study, in order to provide personalized sharing of public transportation data between different users through integrating and sharing these heterogeneous data. This approach not only integrates diverse data types into a uniform data type using the semantic web but also stores these data in a personal online data store and retrieves data through SPARQL on the Solid platform; these data are visualized on the web pages using Google Maps. To the best of our knowledge, we are the first to apply Solid in public transportation. Furthermore, we conduct performance tests of the new C2RMF (CSV to RDF Mapping File) algorithm and functional and non-functional tests to demonstrate the stability and effectiveness of the approach. Our results indicate the feasibility of the proposed approach in facilitating public transportation data integration and sharing through Solid and semantic web technologies.

Effect of Web Post Width on Strength Capacity of Steel Beams with Web Openings: Experimental and Analytical Investigation

Day by day, technology has been changing progressively because of the remarkable hastening of research and development activities. Perforated beams are one such example of advancement in construction technology. Steel beams with web openings are those that have regularly spaced web openings along the length of the beam. The web openings are created in various ways such as wire cutting and welding. Castellated and cellular beams differ in the creation of web openings. Studies addressing the effect of web post width of steel beams with web openings on the strength capacity of beams are rare. Therefore, the objective of the present work was to examine the influence of web post width on the strength capacity of beams with web openings. First, experimental tests were carried out on three full-scale specimens of a steel beam with oval-shaped web openings, cellular beam, and solid web beam. The same beam was modeled using finite-element software ANSYS and the behavior was compared in terms of load–displacement curve and failure modes. Later, a detailed parametric study was carried out to study the behavior of beams with web openings having variation in web post width using nonlinear finite-element analysis. The simply supported steel beams with web openings subjected to midspan concentrated load with varying web post width and shape of openings were modeled and analyzed. From the analysis results, it was found that the shape of web openings and the web post width play an important role in the strength capacity of the perforated beams. The maximum strength reduction capacity was found to be 51.78% for hexagonal openings of depth 150 mm and having a web post width of 50 mm. The minimum strength reduction capacity was found to be 8.93% for hexagonal openings of depth 100 mm having a web post width of 500 mm. Web post width plays a significant role in the ultimate strength capacity of beams. Web post buckling is a predominant failure mode in steel beams with web openings and it can be prevented by maintaining sufficient web post width.

Damage assessment of perforated steel beams subjected to blast loading

Despite the many studies that discussed the structural performance of steel beams with solid web subjected to blasts, the dynamic responses of steel beam with perforated web (PSBs) are not studied up under blast loads till now. In this research, the damage evaluation was numerically investigated under the combination of gravity and blast loading to simulate the realistic case of the external blast near PSBs. The damage indices that will be generated from the residual flexural and shear capacities could give an accurately express about the damage indices than the immediate deformation response after the direct blast shock. Extensive explicit FE analyses using LS-DYNA software are accomplished in order to examine the effects of several parameters including boundary conditions, web opening shapes, and strengthening techniques on toughness and the proposed damage index of the PSBs compared to the parent steel sections. From the comparative results, it was observed that PSBs provide a higher toughness in comparison to their parents through the overall stages of loadings. By changing the boundary condition from pinned to fixed ends, the deformations of PSBs decrease during blast shock directly, despite the toughness increases post the blast effects due to the catenary action that generated by the beam flanges. The beams with sinusoidal web openings and those with elongated circular shape get more toughness than other shapes in the case of fixed and pinned ends respectively. Furthermore, the strengthening strategy by continuous vertical stiffeners has a reliable improvement to get higher toughness in several levels of blast.

System Health and its Prognostics Estimation for Industrial Applications Using IoT

Internet of Things (IoT) is another innovation getting famous with major modern applications, because of its adaptability and execution possibility with any sort of cycle. Presently days it is important to share the information gained from one highlight any region of the planet. Just this is conceivable assuming that the information is posted into the web utilizing trend setting innovation. It needs solid web association and installed server to gain the information and to post it utilizing remote loyalty (Wi - Fi) modules. The information's gathered is stacked into the cloud for additional handling. There are four significant boundary is taken for thought they are pH, Co2 level, stickiness and temperature of the plant. These boundaries are detected and shut circle control framework is intended for two boundaries to keep it inside limits. The installed server is utilized to handle the information and to frame a neighborhood shut circle framework. Aside from controlling these boundaries these information's are shipped off the remote cloud server utilizing a wi - fi module associated with the implanted server a through Wi-Fi modem. There are cloud space is accessible like temboo and think space pages. The figures gathered were stacked into the above mists.

Effect of Web Flexibility in Gear Engagement: A Proposal of Analysis Strategy

Increasing torque and power density in geared transmissions is a constant trend, especially due to the electrification and the research of higher efficiency. Thinner web of the gears has led to potentially higher vibration amplitudes and noise levels, which need to be accounted for in the design stage to avoid fatigue or NVH problems. In the present paper a novel model to represent the dynamic interaction in geared transmissions is presented. The compliances of the shafts are taken into account in two different ways: in a simple strategy, by means of three-dimensional beam elements; in a more detailed methodology, by reduction in a FE model of the gear and shaft assembly. The different gears are connected using kinematic relationships exploited by means of rigid joints and rigid body elements. The flexibility of the teeth and of the gear body is introduced based on an established nonlinear calculation model and is employed as the only dynamic excitation source as a time varying mesh stiffness. Thanks to the reduced size of the matrices a direct integration scheme is used for the time domain analysis of the transmission. Such methodology enables the possibility of modeling dynamic contact loss and torque variations at different rotational velocities with reduced computational times in comparison to other approaches. The technique is then applied to two different geometries of driven gear: one with solid web and one with flexible web. The dynamic behavior of the two different solutions is studied and the differences are highlighted. The proposed approach proves to be more efficient than traditional multibody analyses and quicker than finite element approaches, while maintaining a similar accuracy. It proves to be effective also for studying the transmission with flexible web.

ВЛИЯНИЕ КОНСТРУКТИВНОГО РЕШЕНИЯ НА УРОВЕНЬ НАПРЯЖЕНИЙ В СТА ЛЬНЫХ БАЛКАХ С ОВАЛЬНЫМИ И КРУГЛЫМИ ВЫРЕЗАМИ

With help of FEM it is considering influence of structure design of cellular beams on the stress level in them. It was analyzed scheme of beams containing only regularly located circular openings, regularly located oval openings and variants of perforation with alternate oval and circular openings. All design schemes correspond to real constructions applied in structural practice. Numerical analysis is carried out with help of program complex ANSYS for simply supported beams loaded with concentrated force at midspan. Stress concentration was determined as relation of maximum equivalent stresses on Mises in region of openings to the stress level in flanges of the same sizes beams with solid web. For beams with circular and oval openings it is represented empirical relations for values of maximum stresses.