bluuebunny/crossref_metadata_2025 huggingface dataset:
CLUSTERING OF FACTORS INFLUENCING MANAGERIAL DECISIONS-MAKING OF E-BUSINESS ENTERPRISES
Authors:   Lviv Polytechnic National University, Rusyn-Hrynyk Roman , Pawlowski Grzegorz ,   Zaklad Handlowo-Uslugowy BHP, Pavlenchyk Nataliia ,   Lviv State University of Physical Culture named after Ivan Boberskyj, Pylypenko Iov ,   Lviv Polytechnic National University, Batkovets Nataliia ,   Lviv Polytechnic National University, Kurilina Oksana ,   National Defence University of Ukraine named after Ivan Cherniakhovskyi
Published: November 2022

To ensure the development of e-business enterprises, it is important to obtain reliable and complete information, which directly touches on aspects of the importance of factors that affect the quality, efficiency and, in general, the process of managerial decisions-making, and also concerns issues, related to the effective management of the financial-economic activities of the enterprise in conditions of uncertainty and risk. In the article attempts to theoretically substantiate the concept of «cluster», and accordingly, it is proved that there is no single concept. It is noted that clusters become an innovative mechanism of inter-organizational contacts, which allows establishing efficient and effective cooperation, agreeing business plans of business structures (ebusiness enterprises) that carry out various types of economic activity in today's conditions. Stages and methods of clustering factors that influence managerial decisions-making of e-business enterprises are presented. It has been proved that for more accurate and efficient obtaining of results and decisions, it is necessary to record the initial data in the form of a matrix of observations. The construction of the matrix takes place with the introduction of all factors that affect the adoption of high-quality and effective managerial decisions-making, especially in conditions of uncertainty and risk regarding the achievement of the goals of the financial-economic activity of e-business enterprises. The constructed clusters of factors influencing the adoption of managerial decisionsmaking to achieve the goals of effective financial-economic activity of an ebusiness enterprise require permanent monitoring for their clarification and supplementation, especially during periods of transition of economic development from one phase to another, as well as as a result of the processes of reorganization and restructuring of enterprises.
Amphiphilic Molecules Exhibiting Zwitterionic Excited-State Intramolecular Proton Transfer and Near-Infrared Emission for the Detection of Amyloid β Aggregates in Alzheimer’s Disease
Authors: Mirica Liviu , Yu Zhengxin , Moshood Yusuff , Wozniak Marcin K. , Patel Shrey , Terpstra Karna , Llano Daniel A. , Dobrucki Lawrence W.
Published: November 2022

Chromophores with zwitterionic excited-state intramolecular proton transfer (ESIPT) have been shown to have larger Stock shifts and red-shifted emission wavelengths compared to the conventional π-delocalized ESIPT molecules. However, there is still a dearth of design strategies to expand the current library of zwitterionic ESIPT compounds. Herein, we report a novel zwitterionic excited-state intramolecular proton transfer system enabled by addition of triazamacrocycle (TACN) fragments on a dicyanomethylene-4H-pyran (DCM) scaffold. The solvent-dependent steady-state photophysical studies and pKa measurements strongly support that the ESIPT process is more efficient with two TACN groups attached to the DCM scaffold and not affected by polar protic solvents. Impressively, compound DCM-OH-2-DT emits with a near-infrared (NIR) emission wavelength at 740 nm along with an uncommonly large Stokes shift of ~ 280 nm. Moreover, DCM-OH-2-DT shows high affinity towards soluble amyloid β (Aβ) oligomers in vitro and in 5xFAD mouse brain sections, and we have successfully applied DCM-OH-2-DT for the NIR fluorescence in vivo imaging of Aβ aggregates and demonstrated its potential use as an early diagnostic agent for AD. Overall, this study can provide a general molecular design strategy for developing new zwitterionic ESIPT compounds with NIR emission for further in vivo imaging applications.
Connecting the Dots for Fundamental Understanding of Structure-Photophysics-Property Relationships of COFs, MOFs, and Perovskites using a Multiparticle Holstein Formalism
Authors: Ghosh Raja , Paesani Francesco
Published: November 2022

Photoactive organic and hybrid organic-inorganic materials, such as conjugated polymers, covalent organic frameworks (COFs), metal-organic frameworks (MOFs), and layered perovskites, display intriguing photophysical signatures upon interaction with light. Elucidating structure-photophysics-property relationships across a broad range of functional materials is nontrivial and requires our fundamental understanding of the intricate interplay among excitons (electron-hole pair), polarons (charges), bipolarons, phonons (vibrations), inter-layer stacking interactions, and different forms of structural and conformational defects. In parallel with electronic structure modeling and data-driven science that are actively pursued to successfully accelerate materials discovery, an accurate, computationally inexpensive, and physically-motivated theoretical model, which consistently makes quantitative connections with conceptually complicated experimental observations, is equally important. Within this context, the first part of this Perspective highlights a unified theoretical framework in which the electronic coupling as well as the local coupling between the electronic and nuclear degrees of freedom can be efficiently described for a wide range of quasiparticles with similarly structured Holstein-style Hamiltonians. The second part of this Perspective discusses excitonic and polaronic photophysical signatures in polymers, COFs, MOFs, and perovskites, and makes a unique attempt to bridge the gap between different research fields using a common theoretical construct - the Multiparticle Holstein Formalism. We envision that the synergistic integration of state-of-the-art computational approaches with the Multiparticle Holstein Formalism will help identify and establish new, transformative design strategies that will guide the synthesis and characterization of next-generation energy materials optimized for a broad range of optoelectronic, spintronic, and photonic applications.
Label-free measurement of antimicrobial peptide interactions with lipid vesicles and nanodiscs using microscale thermophoresis
Authors: Rainsford Philip , Rylandsholm Fredrik , Jakubec Martin , Juskewitz Eric , Silk Mitchell , Engh Richard A. , Isaksson Johan
Published: November 2022

Antimicrobial peptides (AMPs) are a promising source of inspiration for new antibiotics discovery, in part because they believed to not trigger rapid resistance development since AMPs have co-existed with bacteria throughout evolution and do not target a single enzyme encoded by a single gene. AMPs is a diverse class of molecules that have diverse and often unspecific modes of action interfering with the membrane potential or the bacterial cell wall integrity, but also intracellular targets have been reported. Regardless of the mode of action(s), the AMPs will first have to interact with-, or penetrate through-, the bacterial cell well, and early characterization of AMP activity relies on the determination of the KD (dissociation constant for binding affinity) and the KP (partitioning constant) of AMP:lipid interactions. Here we demonstrate that microscale thermophoresis (MST) can be used for reliable unlabelled measurement of KD and KP utilising the intrinsic tryptophan fluorescence, thus removing the need for chromophore labelling. The MST results of binding to small unilamellar vesicles (SUVs) and stryrene maleic acid (SMA) based nanodiscs are compared to the corresponding surface plasmon resonance (SPR) measurements. SMA-QA nanodiscs are shown to be best suited for accurate measurements, while vesicles are a viable alternative. Unmodified SMA-nanodiscs proved unsuitable due to interactions between the cationic AMPs and the anionic polymer belt. Significant reduction of KD was observed when 5% anionic lipids were included in the lipid composition of the membrane models. This highlights the preference of the tested AMPs for anionic bacterial membranes, and the measured KD and KP values correlate well with their activity towards S. aureus and E. coli. We conclude that MST is a promising method for fast and efficient detection of peptide-lipid interactions, and the relative strength of the interactions can be reliably ranked within a library of screened compounds.
Alchemical osmostat for MC simulation: Sampling aqueous electrolyte solution in open systems
Authors: De Izarra Ambroise , Coudert François-Xavier , Fuchs Alain , Boutin Anne
Published: November 2022

Molecular simulations involving electrolytes are usually performed at a fixed amount of salt ions in the simulation box, reproducing macroscopic concentration. Although this statement is valid in the bulk, the concentration of an electrolyte confined in a nanoporous materials such as MOFs or zeolites is greatly affected and remains a priori unknown. The nanoporous material in equilibrium with the bulk electrolyte exchange water and ions at a given chemical potential in the semigrand canonical ensemble that must be calibrated in order to determine the concentration in the nanoporous material. In this work, we propose an algorithm based on non-equilibrium candidate Monte Carlo (NCMC) moves to ultimately perform MC simulations in contact with a saline reservoir. First, we adapt the Widom insertion technique to calibrate the chemical potential by alchemically transmuting water molecules into ions by using NCMC moves. The chemical potential defines a Monte carlo osmostat in the semigrand constant volume and temperature ensemble to be added in a Monte Carlo simulation where the number of ions fluctuates. In order to validate the method, we adapted the NCMC move to determine the free energy of water solvation and subsequently explore thermodynamics of electrolyte solvation at infinite dilution in water. Finally, we implemented the osmostat in MC simulations initialized with bulk water that are driven towards electrolytes of similar concencentration as the saline reservoir. Our results demonstrate that alchemical osmostat MC simulation is a promising tool for use to sample electrolyte insertion in nanoporous materials.
Aprendizaje basado en investigación: estudio de caso de Proyecto Dirigido en ingeniería civil
Authors: Serrano Guzmán María Fernanda , Perez Ruiz Diego Dario
Published: November 2022

En la asignatura Proyecto Dirigido de Ingeniería Civil de la Pontificia Universidad Javeriana Cali se ha contemplado un contenido centrado en investigación formativa donde el estudiante de pregrado resuelve un problema académico propio de la industria empleando el método científico bajo un esquema de trabajo independiente supervisado por el docente. El curso no posee un currículo definido por el programa y en su lugar, cada docente sigue un estilo pedagógico centrado en la investigación constituyéndose en una asignatura con verdadera libertad de cátedra. El objetivo de este estudio es conocer la percepción del estudiante frente al abordaje de problemáticas de su entorno ocupacional haciendo uso de la investigación. Para adelantar el estudio se recopiló información contactando a los estudiantes que matricularon la asignatura durante seis semestres. Se concluye, que la investigación facilita la enseñanza, pero no debe imponerse su uso en todas las asignaturas
Enseñanza basada en problemas aplicada a la Ingeniería Química. Análisis bibliométrico: estudio comparativo de Scopus y WoS
Authors: Díaz Oliver , Segredo-Morales Elisabet , Gonzalez Enrique
Published: November 2022

La convergencia al Espacio Europeo de Educación Superior requiere la introducción de nuevas metodologías docentes con el fin de fomentar el autoaprendizaje, la adquisición de competencias profesionalizantes y la transmisión de conocimientos. La enseñanza basada en problemas es un método de innovación docente que permite que los estudiantes adquieran, estructuren y sinteticen de manera colectiva nuevos conocimientos que aplican ante casos reales. La enseñanza basada en problemas en el área de la ingeniería química comenzó a finales del siglo XX, sin embargo, la aplicación de este tipo de metodología no está completamente generalizada. Este trabajo presenta un estudio bibliométrico sobre la utilización de la enseñanza basada en problemas en la ingeniería química utilizando las dos principales bases de datos actuales (Scopus y WoS). Se han encontrado un total de 113 y 89 documentos en Scopus y WoS, respectivamente. Existe una mayor prevalencia de participaciones en congresos, frente a otros medios de publicación y el lenguaje mayoritario es el inglés. La mayor producción científica sobre el campo analizado se encuentra en Estados Unidos, aunque existe un interés generalizado en los cinco continentes. El análisis de las palabras clave muestra un creciente interés por la motivación del alumnado y la enseñanza activa dirigida a aspectos prácticos y profesionalizantes claves en la enseñanza de la ingeniería química.
A Research Protocol and Case Report of Emergency Department Endovascular Aortic Occlusion (REBOA) in Non-traumatic Cardiac Arrest
Authors: Daley James , Cannon Kathryn , Buckley Ryan , Aydin Ani , Latich Igor , Lozada Juan Carlos Perez , Bonz James , Joseph Daniel , Coughlin Ryan , Belsky Justin , Van Tonder Reinier , Sather John , Wira Charles , Liu Rachel , Johnson Austin , Moore Christopher
Published: November 2022

Background: There are over 395,000 out-of-hospital cardiac arrests (OHCA) annually in the United States with an estimated 70–90% mortality rate and fewer than 10% surviving with a favorable neurologic outcome. Research in animal models and early human studies suggests that resuscitative endovascular balloon occlusion of the aorta (REBOA) may play a role in augmenting coronary perfusion during OHCA by reducing blood flow to the lower body and re-directing it towards the heart and the brain. We describe our initial case and research protocol to investigate the feasibility of REBOA in the emergency department for OHCA as an adjunct to advanced cardiac life support.Methods: We plan to enroll 20 patients in a single-arm interventional device study utilizing an exception from informed consent over a 2-year period. The primary outcome is feasibility, with secondary outcomes assessing for hemodynamic changes pre- and post-aortic occlusion.Results: Enrollment began in January 2020 and is ongoing. For the initial patient, an emergency physician (EP) obtained common femoral arterial access under chest compressions, followed by advancement of the REBOA catheter by an interventional radiologist. Immediately after aortic occlusion, investigators noted a substantial improvement in mean arterial pressure (37 mmHg to 50 mmHg) and end tidal carbon dioxide (33 mmHg to 50 mmHg), with transient but non-sustained return of spontaneous circulation.Conclusion: This is the first research protocol and case report describing successful REBOA placement in the emergency department (ED) involving EPs for non-traumatic OHCA as an adjunct to advanced cardiac life support.
A Qualitative Comparison between Three Different Microflu- idic Devices with Roughened Surfaces Regarding Cavitation Inception
Authors: Ghorbani Morteza
Published: November 2022

Small bubbles generated via hydrodynamic cavitation as a result of the decrease in pressure within flow restrictive elements have wide applications. The recent studies have demonstrated their potentials in the biomedical applications, image processing and energy sectors. Therefore, the formation of the cavitation bubbles with the consideration of the surface topology has taken considerable attention particularly in the micro scale. In this study, two different microfluidic devices, which house significantly and slightly roughened microchannels, were fabricated to investigate the inception of the cavitation phenomenon. The roughness elements were created as nano grasses on the surface of the channels with the aid of the techniques adopted from semiconductor based microfabrication. Accordingly, the liquid flow was guided into the devices at different upstream pressures to record the inception of the cavitation and to investigate the size effect of the surface roughness. The results indicate that the significantly roughened (the peak-to-peak roughness is about 5 μm) device has the potential for leading to cavitation inception at lower upstream pressures. Moreover, the intensity of cavitating flows forming inside this device is high enough to fill the entire microchannel even at lower upstream pressures. On the other hand, cavitating flows do not extend along the microchannel for the device with smaller roughness element (the peak-to-peak roughness is about 1μm) even at high upstream pressures. The concept of this study could be employed in the design of microfluidic devices, which could use to facilitate intense cavitating flows.
Challenges and Innovations in Design and Construction of Supersized Structural Components for Long Span Bridges
Authors: Qin Shunquan , Jiang Zhenxiong , Yuan Renan , Qin Jingxi
Published: November 2022

For better cooperating river-crossing highway and railway with waterway transportations, larger spanning capability of a bridges is more demanding than ever before. Larger spans lead to supersized structural components, bringing new technical challenges to the design and construction of bridges. This paper summarizes several recent engineering innovations in the design and construction of supersized structural components for super long span bridges, including thermal-adapting tower-deck restraint system, spatial diamond-shaped tower, steel-box and core-concrete composite anchorage system, scour-mitigating skirted caisson foundation, and vortex-induced-vibration control of the main girder, so as to provide viable solutions for the design and construction challenges brought by supersized structural components of long span bridges.
Assessment and Retrofitting of Existing RC Buildings – Recent Trends
Authors: Dritsos Stephanos E.
Published: November 2022

Most of the existing old structures are vulnerable under seismic actions, due to certain weaknesses that result from poor design knowledge at the time of construction. Critical matters concerning the behaviour of RC structures under earthquake actions were ignored, such as ductility, capacity design, adequate code provisions for detailing of RC elements (minimum number of stirrups, lower limit for compressive and upper limit for tensile reinforcement). A number of approximations and simplifications were adopted in the analysis. Computers were not in use; 3D analysis was impossible and 2D analysis was rarely used. Usually, beams and columns were considered as independent elements. Seismic actions considered in the past were lower than those currently accepted for new structures. In this context, some crucial questions arise: Which structures are more vulnerable and, therefore, have priority to be strengthened and how to identify them? Is it possible (or is it worth) strengthening these structures and to what extent? Is this preferable when compared to the demolition and reconstruction solution? What resources (materials, methods, techniques) are available to intervene and under what standards are they to be applied? Which is the framework to assess the seismic capacity of an existing structure and how to further design the necessary intervention for retrofitting or strengthening? What are the quality control procedures for intervention works?

Redesign of existing structures is a much more complicated task than the design of new ones. Not only there is limited knowledge on this subject, but also existing codes and regulations are relatively new, with the engineering practice not being familiar with them. Furthermore, the configuration of an existing structural system may not be permitted or may be wrong according to our present knowledge, however, it exists and we must deal with this. Usually, there is also a high uncertainty in the general data (geometry, materials, details, hidden errors or faults, etc.). In the present keynote lecture, assessment and retrofitting procedures are analyzed in five stages. In the first stage, the data of the existing structure is documented. Different data knowledge levels define different confidence factors, depending on the extend and detail of the data documentation. Stage two concerns the assessment of the seismic capacity of the structure. The acceptable level of damage is defined through different performance levels or limit states. The third stage involves the decision on whether a structural intervention is required and to what extent. The fourth stage includes the design of the structural intervention, following certain seismic strengthening strategies. The fifth and final stage concerns the construction of the intervention work. Since during this stage new data might arise, frequently the design of the intervention (stage four) should be updated accordingly.
Key Technologies of Precast Segment Production for the 4th Ring Transportation Corridor in Zhengzhou, Henan, China
Authors: Sun Junling , Lei Wenbin , He Yongping , Peng Chongju , Komar Gernot
Published: November 2022

The 4th Ring Transportation Corridor in Zhengzhou, Henan, China (the Project) is implemented in accordance with the design scheme of integral bridge structures and the short-line match casting method. This paper focuses on key technologies of segment precasting used in the Project, involving the design and layout of precast yards, the formwork design for precast segments and the geometry control in the precast yards as well as the application of information technology in precast yards. It can be used as references for projects related to precast segment production in the industry.
Design of Rail Viaducts over the Hajar Mountains
Authors: Moreno Grecia , Joy Emmanuel , Catalán Iñaki
Published: November 2022

Major railway bridges across the Hajar mountain range belonging to the Etihad Rail Package D of Stage Two of the UAE National Railway Network are built above important wadis and roads.

Standard railway bridges are articulated in 40m long simply supported spans. Tall piers and abutments are required due to the complex terrain and the rail alignment configuration.

Construction logistics and program being key constraints, solutions featuring precast elements have been favoured. The bridge section is made of 7 post-tensioned precast I-girders of 2.50m depth and a reinforced concrete top slab supporting the ballasted track system.

The aim of this paper is to describe the structural system as well as to discuss some important design related aspects related to the precast girder type railway bridges built across the Hajar mountains.
Upgrading the 4th Ring Transportation Corridor in Zhengzhou, China - Optimized Camber Analysis for close to 1,200 Precast Bridge Frames
Authors: Komar Gernot , Sun Junling , Lei Wenbin , Peng Chongju
Published: November 2022

The City of Zhengzhou is a major transportation hub in the heart of China. The fast-growing city was in need of an additional elevated expressway to increase the traffic capacity from 10 lanes to 18 lanes on the 4th Ring Transportation Corridor. The additional elevated expressway has a total length of 93.3 km and faced complex boundary conditions. 1,200 different bridge-frames were designed for the elevated expressway. The precast segmental bridge frames are continuous girders or rigid frame systems. The short-line match-casting system was utilized for the fabrication of close to 50,000 unique segments. Parameter studies were performed to better understand the influence of the boundary conditions and to optimize the camber analysis. This approach reduced the modeling effort tremendously and allowing the camber data for 1,200 bridge-frames to be analyzed in an accelerated time frame. The largest precast segmental bridge project in the world was partially opened to traffic in 2020 and is now fully operational.
Innovations and Breakthroughs in China’s Zhangjinggao Yangtze River Bridge
Authors: Li Hongtao , Wang Rengui , Wei Leyong
Published: November 2022

The Zhangjinggao Yangtze River Bridge currently under construction is located in the lower reach of the Yangtze River in Jiangsu Province, China, connecting the cities of Zhangjiagang, Jingjiang, and Rugao. It consists of two river-crossing bridges, one on the south channel and the other on the north channel of the Yangtze river. The south channel bridge is a double-span suspension bridge. In order to minimize the impact of bridge construction on the water traffic and the ecological environment of the Yangtze River, the beam span layout is designed to be 2300 m +717 m, and the cable span layout is 660 m + 2300 m+ 1220 m. When the construction is completed, it will become the world's longest span bridge, which is a veritable world-class mega structure. Since the bridge span breaks the records of all the existing bridges in the world, there is no standard to refer to and no experience to learn from. In order to solve the technical problems brought by the mega long span, the project construction team has utilized technological innovations, proposed six new world concepts, and therefore set six world records.
ShiZiYang Bridge – Large diameter main cables
Authors: Duris Jakub , Marcussen Jens Brolev , Jamal Assad , Pihl Jesper
Published: November 2022

The ShiZiYang suspension bridge in the GuangDong province in China will when constructed have a world record main span of 2180 m and carry an impressive 2 x 8 lanes of traffic on the two levels truss girder.

Due to its size, ShiZiYang bridge requires extensive main cable area with diameter nearly 1.5 m representing the largest main cable ever constructed. An option of dual main cables can be considered with smaller main cables including simpler compaction. However the construction time is extended, all adjacent structures such as saddles, anchorages and cable clamps become significantly more complex and the separate cables behave as independent members.

The paper discusses the main key challenges regarding design and construction of large main cables with diameter above 1m and alternatively dual main cables.
Archimedes Bridge Underwater of BaiYangDian Lake
Authors: Zhi-Bo Teng
Published: November 2022

Based on the concept to build a floating bridge being the mixture of bridges and tunnels on anchored submarines, this paper tells a conceptual design of 3x50 Archimedes bridge underwater of BaiYangDian Lake, and also of prospectives on the same type of Archimedes bridge for TaiWan Strait.
Overall Design of the Nanjing Jiangxinzhou Yangtze River Bridge
Authors: Leyong Wei , Yonglun Yan , Liji Huang , Zeng Ma , Yingtong Song
Published: November 2022

This paper systematically introduces the overall design concept of the Nanjing Jiangxinzhou Yangtze River Bridge. The main bridge is a three-tower cable-stayed bridge featuring a longitudinal diamond cable tower and dual central cable planes. The bridge span is designed to be a total of 80+218+600+600+218+80 = 1796m. A steel-shell composite cable tower design is adopted, with the main girder including a high-performance steel-coarse aggregate reactive powder concrete

（CA-RPC） composite girder structure. The cable tower uses cast-in-situ bored pile group foundations, and the stay cables are formed of steel strands. The south and north approach bridges use segmented prefabricated prestressed concrete box girders. The bridge over the river dyke uses a continuous box girder made of prestressed corrugated steel webs for the 78m span and the construction technology of segmented prefabrication has being used for the first time. Nanjing Jiangxinzhou Yangtze River Bridge has become a classic engineering structure which not only environmentally-friendly, but also meets all requirements of industrial construction attributed to the application of a high-performance composite structure for the main bridge, as well as large-scale prefabricated assembly structures for approach bridges and bridges over river dykes.
Benefits and Challenges of the Twin-box Bridge Girder
Authors: Larsen Allan , Sørensen Jesper W.
Published: November 2022

The aerodynamics of the twin-box bridge is considered to highlight the reasons for making this type of bridge deck superior to the conventional trapezoidal mono-box for suspension bridges having span lengths longer than 1800 m. The paper proposes a simple theoretical model yielding physical insight into the flutter stability and presents a design example comparing the flutter performance of a 2000 m main span suspension bridge designed with either a mono-box or a twin-box bridge girder. Experience from vortex induced vibration of twin-box bridges is discussed to demonstrate that a twin-box girder can be designed to avoid vortex induced for practical damping levels.
Multilevel Decomposition Model for Optimal Design of Multi-Story Structures
Authors: Chornay Morn , Zhao Xin
Published: November 2022

Multilevel decomposition optimization method decomposes a large problem into small subproblems to be solved separately and maintain effects between subproblems effectively by sensitivity derivatives, and it serves as a useful tool for design engineer team to work on a large structural optimization problem simultaneously and effectively. The present paper illustrates the application of this method on the optimization of a portal frame of a multi-story steel structure, and three level of substructure is chosen to solve the optimization problem. The 1st level is the entire structural system constrained to total lateral displacement, the 2nd level is each story frame constrained to story drift, and the 3rd level is related element sizing based on local constrains due to strength, serviceability, and member stability.
Wind Induced Response Analysis and Vibration Mitigation Design for Steel Tall Buildings Equipped with Viscous Dampers
Authors: Zhao Xin , Hou Yuzhou , Chen Jianan , Xu Yutong
Published: November 2022

The wind induced response of the steel tall building is obvious. Controlling the wind induced response of steel tall building can effectively improve the comfort, stiffness and strength performance of the structure. A large number of studies have shown that equipping damping device is a more effective wind-induced vibration control measure than increasing the structure stiffness. Viscous damps can achieve multi-load and multi-performance structure vibration reduction and have a very broad engineering application prospect. In this paper, the wind induced response of steel tall building and the viscous damper system are studied to ascertain the optimal arrangement and quantity of viscous damps and a 150m steel residential tower is taken as an engineering case, which shows that the integrated viscous damps can effectively improve the structure performance of steel tall building under wind load and reduce the steel consumption of the structure.
Numerical Ward-Type Tornado Simulator and its Application to Transient Wind-Induced Response of Long-Span Bridges
Authors: Feng Yu , Hao Jianming , Wu Teng
Published: November 2022

In this study, the tornado-like wind field is simulated by the numerical Ward-type tornado simulator based on computational fluid dynamics (CFD) techniques. To minimize the discrepancy between the simulated and field-measured tornado winds, the optimization strategy is developed to achieve optimal parameters of the numerical Ward-type tornado simulator, namely the inflow angle and translation speed. To facilitate the optimization process, a multi-fidelity surrogate model is utilized to effectively integrate both low-fidelity and high-fidelity data for accurate and efficient simulations. The “best” parameters based on the multi-fidelity surrogate model is input to the numerical Ward- type tornado simulator (using LES technique). Finally, the transient wind field generated using the validated numerical Ward-type tornado simulator is employed as the dynamic inputs to the finite element (FE) model of a long-span bridge.
Study on the Self-Balancing System of 2300m Main Span Suspension Bridge and Relative Mechanical Characteristics
Authors: Rengui Wang , Leyong Wei , Zhifa Yan , Qinghai Feng , Ruili Shen , Hongtao Li , Jing Ruan , Haifeng Lin , Junping Dai , Feng Zhao
Published: November 2022

Zhangjinggao Yangtze River Bridge has a main span of 2300 m, and a tower height of 350 m. A huge bending moment at the tower bottom under operation loads would happen if the traditional fixed restraint system between the saddle and the tower top were adopted. In the actual design, a movable saddle was used as a self-balancing device at the tower top, releasing part of the shear force, thus reducing the bottom bending moment. Due to friction, the movable saddle on the flexible tower complexes the structural calculation model and force transmission mechanism. This study established a computational model of the longitudinal movable saddle to analyze the static response and the mechanical properties including the consideration of the influence of friction. The study shows that the self-balancing system significantly reduced the maximum bending moment at the tower bottom under a vehicle load and/or a temperature load. Whereas this system increased the bending moment of the tower under a longitudinal wind load. Large friction coefficients undermined the effect of the self-balancing system.
Analysis of Reasonable Longitudinal Restraint System of Four-Tower Cable-Stayed Bridge
Authors: Wang Hui , Shen Ruili , Cheng Xiang
Published: November 2022

The four-tower cable-stayed bridge with four towers and three main spans can be set up with various symmetrical and asymmetrical longitudinal restraint schemes for the whole bridge. Different longitudinal restraint systems will directly affect the load transfer path and change the mechanical behavior of the four-tower cable-stayed bridge structure, which in turn affects the structural design of the bridge. Taking a four-tower cable-stayed bridge as the research object, the structural mechanical behaviors of semi-floating system, temperature adaptive system, middle two- tower elastic cable restraint system, and middle single-tower longitudinal fixed restraint system under the effect of temperature load, longitudinal wind load, and load combination are compared and analyzed. The results show that the semi-floating system will cause a larger longitudinal displacement of the main beam, which will increase the internal force of the side towers substantially. Increasing the restraint of the main beam and the middle towers can make the four towers' forces uniform.The temperature adaptive system and the middle two towers elastic cable system have better feasibility.
Experimental Study of the Post-Tensioned Prefabricated Retaining Blocks with Mortise-Tenon Joint
Authors: Wu Wenpeng , Ye Xin , Yao Yongjiao , Li Lifeng
Published: November 2022

Conventional sacrificial shear keys in both bridge abutments and pier cap beams have been proved to be helpful to limit the over displacement of the superstructure under the designed earthquake event. However, the advantage of the sacrificial shear keys depends on the severe damage of the shear key itself or the stem wall, which would completely break off the mechanical connection between one concrete component and another. In addition, it is time-consuming and costly to repair and reinforce the conventional shear keys once it is severely damaged in huge earthquake event. Therefore, this paper proposed a novel post-tensioned prefabricated concrete retaining block with mortise-tenon joint. Four retaining block specimens were designed and tested to study its anti- seismic effectiveness and basic mechanical properties. The influence of the structural material and forms on seismic damage mode of the proposed retaining blocks were investigated.
Corresponding Force Matrix: A Bridge Connecting Refined Analysis and Reinforcement Design of Box-section Girders Based on Shells
Authors: Zhang Yu , Jiang Haili , Xu Dong
Published: November 2022

Benefitting from the development of computing power, box girders can be analysed in a more refined way by discretizing cross-sections into shell elements. However, how to take full advantage of the analysis results in the reinforcement design process remains a problem. To solve this problem, the concept of “corresponding force matrix” is proposed in this paper. The matrix has 6 columns corresponding to the key unit force resultants of a specified location, and 12 rows corresponding to all the possible unfavourable cases. For each row, only one force resultant reaches its maximum (or minimum) under loads while the others take the corresponding values. Then the construction method of the proposed matrix under live loads and load combinations is described, respectively. After that, two reinforcement design methods with the use of the matrix were introduced and compared. Finally, discussions and preliminary conclusions are made.
Buckling behavior of stiffened plates in concrete-filled steel tubular bridge towers
Authors: Sun Lipeng , Liu Yongjian
Published: November 2022

The steel panels on concrete-filled steel tubular bridge towers are large aspect ratio stiffened plates subject to unilateral restraint from concrete, whose local stability performance can be improved by setting multiple longitudinal stiffeners. In this paper, the elastic buckling coefficient of such a unilaterally restrained stiffened plate was derived using the Ritz method. Then, the critical relative stiffness of the stiffeners was proposed to identify the buckling mode of the plate. Further, the effective area method was proposed to evaluate the ultimate strength of the stiffened plates. The numerical simulation of the unilaterally restrained stiffened plates under axial compression was conducted using the verified finite element models. The results show that the buckling coefficient and effective area method proposed in this paper can evaluate the ultimate strength of unilaterally restrained stiffened plates under axial compression with high accuracy.
Desirable Geometrical Configurations of The Web/Flange Splices for Enhancing the Frictional Slip Resistance of an I-Girder
Authors: Sakura Ryo , Yamaguchi Takashi
Published: November 2022

The present study focuses on the major slip behavior of high-strength frictional bolted connections in an I-girder. Bolted girder connections resist the applied bending moment through the cooperation of flange and web resistances. Flange and web splices are individually designed following practical design codes, such as Eurocode 3 and the Japanese Specifications for Highway Bridges. In the present study, FEA of various cross-sectional dimensions of the web splice in girder bolted connections, having various bolt arrangements of the web splice, and various number of bolts in the flange and web splices have been conducted to quantitatively evaluate the cooperative slip behavior of the girder connections. It has been found that the frictional force of the web splice was small compared to the design resistance. Moreover, as the bolt spacing of the web splice increased and the number of bolt rows of the web splice decreased, the ratio of the frictional force to the design slip resistance increased.
Effect of SFRC Composite Deck on Negative Bending Behavior Steel Box Girder
Authors: Xu Yi , Xu Chen , Abbas Sheraz , Sun Xuxia
Published: November 2022

To investigate the failure mode and effect on a steel girder negative bending behavior of an SFRC composite deck, eccentric tension tests and numerical simulations were conducted on C50 concrete composite deck and SFRC composite deck specimens. Furthermore, parametric analysis via girder segment finite element models was carried out for summarizing the influences of the composite deck on the steel box girder performance. The test and simulation analysis results showed that the residual contribution of SFRC slab to the axial tensile stiffness of composite deck was 36% as cracking up to 0,10 mm, while that of C50 concrete slab was only 15%. Moreover, the parametric analysis results showed that the residual contribution of SFRC slab to the bending stiffness of steel girder was twice that of C50 concrete slab. When SFRC crack width reached 0.10 mm, the bending stiffness of the main girder was reduced by 11% compared with the intact state.
Seismic Response Analysis for Engineering Structures Equipped with Double Viscous Damper Toggle Brace System
Authors: Wang Gang , Zhao Xin , Chen Huaikun
Published: November 2022

The toggle brace viscous damping system has been proved to be an effective motion amplification device, which can amplify the deformation of the damper under wind load and earthquake action, thus significantly improving the energy dissipation efficiency of the damper. In the existing viscous damping system of elbow joint, the damping force will act directly on the floor beam, which often leads to unsatisfied performance of the connected floor beam. Therefore, a double-damper toggle brace device is proposed in this paper, and a mathematical model of geometric parameter optimization of double-damper toggle brace device system is established. According to this mathematical model, a larger displacement amplification factor can be obtained, which is far superior to the existing toggle damping system. Finally, a two-story steel frame model is taken as an example to verify the effectiveness and applicability of the proposed double-damper toggle brace device system.
Flexural Behavior of a New Steel-UHPFRC Composite Beam with In- Built Steel Dowel as Connector
Authors: Shen Xiujiang , He Yaobei , Li Yu , Shao Xudong
Published: November 2022

A lightweight steel-UHPFRC composite beam structure, consisting of a half rolled section with in- built steel dowels as connectors and a T-shaped UHPFRC component, is proposed originally in this paper. The excellent properties of steel and UHPFRC materials can be exploited fully and properly, and the presence of in-built steel dowel is expected to allow effective force transmission between steel and UHPFRC components, benefiting from its higher shear resistance and ductility. Two composite beams with various heights of UHPC web are tested by 4PBT method, aiming at validating this concept and investigating the flexural behavior under sagging moment. And a high resolution Digital Image Correlation (DIC) system is applied during testing, in addition to conventional measuring techniques. Moreover, the sectional analysis method considering the tensile properties of UHPFRC is applied to predict the flexural.
Design and Application of New Steel-UHPC Composite Slab Girder Bridge
Authors: Hao Dong , Lin Chen
Published: November 2022

A project is located in the core area of the high-speed railway station, subject to large traffic volume and various controlling factors. A new steel-UHPC composite slab girder bridge is adopted based on and taking into account the characteristics of the project. Compared with the conventional structure, the self-weight of the bridge superstructure is greatly reduced; meanwhile, the size and weight of the lower part of the bridge are further reduced due to the fact that the prestressed concrete bent cap with large volume and weight is replaced by steel box beam; the fact that longitudinal and transverse beams are connected by high-strength bolts speeds up the on-site construction progress. Furthermore, components of the project have light self-weight and are easy to transport and install, which further reduces the impact of the construction on the environment. This paper introduces the design scheme and stress analysis of the new steel-UHPC composite beam structure, with the aim of providing reference for similar projects in the future.
FE Modeling of the Interfacial Behaviour of Precast Multi-box Girder
Authors: Zhang Juhui , Zhao Yuchuan
Published: November 2022

To facilitate the reuse of the internal mold of precast multi-box girder and accelerate bridge construction, the torsional crossbeam at the end of precast simply supported multi-box girder needs to be changed to post-cast in-situ. Finite Element Modelling package ABAQUS 2021 was used to model the interfacial shear behaviour of the three-dimensional Z-shaped straight shear specimens. The models took into account the bond-slip relationship between the old and new concrete interfaces and the interaction between the concrete and the shear key. The models were validated and calibrated based on the experimental results. The study shows that the rigid shear key can improve the shear load capacity of the specimen at the new and old concrete interface. The difference between the model and experimental results is relatively small and therefore it shows the capability of the finite element modelling to carry out parametric analysis.
Experimental and Numerical Study of Welding Residual Stress Distribution in Shear Keys
Authors: She Junhui , Chen Tao , Ni Kelei
Published: November 2022

Welding technologies are widely applied in all kinds of steel structures. No matter what kind of welding is used, the welding residual stress is always inevitable. So, in this research, a semi- destructive experiment and a numerical simulation are conducted to study the welding residual stress distributions of shear keys in the grouted connection section. The experiment uses the blind hole method on 3 flat-plate specimens of the sleeve section, to measure the welding residual stress distributions of them, which gives an approximate distribution of the real grouted connection section. Based on the experiment, a FEM numerical simulation is performed to estimate welding residual stress distribution. During the numerical simulation, EBD (Element Birth and Death) and Dflux subroutine are applied to maintain a better precision. Through the experiment and simulation, a comparison is done and a good correlation between welding residual stresses was found.
Finite Fault Source Model for Ground Motion near Fault Zone
Authors: Qiu Yuan , Ma Haiying , Xia Ye , Lai Minghui , Turmo José , Lozano-Galant J. A.
Published: November 2022

Ground motion is categorized into near fault zone and across fault zone where impulsive component is included. The impulsive component usually causes larger damage than that by far-fault ground motion. To build a Benchmark model platform for cable-stayed bridges across-fault region for comparative analysis, the paper proposes a way combining the finite fault source model. In the paper, the finite fault source model was conducted based on the site Qiongshan earthquake. After the geological structural parameters were determined, forward modeling of near site earthquake was carried out, and the observation points were obtained using numerical simulation. Then, the analysis results were compared with the pulse characteristic parameters of similar grade of recording ground motion. Additionally, the ground motion near-fault region was analyzed to validate the finite fault source model.
Implementation of Neural Networks for the Calibration of a Macroscopic Model of a Lead-Core Bearing Device
Authors: Zhelyazov Todor , Rupakhety Rajesh , Ólafsson Símon
Published: November 2022

The increasing popularity of the lead-core bearing devices motivates the research efforts devoted to a more accurate behavior assessment. The contribution provides details of an accurate finite element model of the bearing device. The geometry is reproduced in great detail. Material models are defined for the rubber layers, steel elements, and lead core. The output of the finite element simulations provides an insight into the bearing response, for example, through the numerically obtained ‘Restoring force- displacements’ relationship. The definition of a less demanding model of the lead-core rubber bearing about an implementation into the finite element analysis of a base-isolated structure might be an attractive option. Some elements of the implementation of a neural network for the identification of the model parameters based on results obtained by finite element analysis are discussed.