bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatigue strengthening of cracked steel plates with bonded Fe‐SMA strips
Authors: Li Lingzhen , Wang Sizhe , Chen Tao , Chatzi Eleni , Heydarinouri Hossein , Ghafoori Elyas
Published: September 2023

Prestressed fatigue strengthening of steel structures has been proven effective by numerous investigations. Bonded iron‐based shape memory alloy (Fe‐SMA) strengthening has shown a great potential in this regard, however, with limited corroborating studies. Moreover, a proper model for fatigue analysis of systems that are retrofitted with bonded Fe‐SMA strengthening is missing. In this study, an analytical model, coupling prestress analysis and fatigue analysis, is proposed. Four steel plates with central through‐thickness cracks were strengthened with use of bonded Fe‐SMA strips, and subsequently tested under fatigue loading after generating prestress via heating and cooling. The fatigue behavior predicted by the proposed model lies in excellent agreement with the fatigue testing results.
Fatigue stress concentrations analysis of real corroded steel structures based on replica imprints
Authors: Shojai Sulaiman , Schaumann Peter , Momber Andreas , Ghafoori Elyas
Published: September 2023

The service life of offshore support structures is significantly reduced by corrosion. In particular, pitting corrosion leads to high local stress concentrations and can reduce the expected fatigue strength. Previous studies on corroded specimens have shown that crack development in fatigue tests is correlated with stress concentration. In the context of maintenance of existing offshore wind turbines, there are novel efforts to capture the real surface geometry of corroded components with the so‐called replica technique, in which an imprint of the surface geometry is made and digitized with a 3D‐scanner and used to numerically analyse the stress concentrations due to pitting corrosion. In this study, it was shown that the replica technique is able to reproduce the effective stress concentrations of the original surface with very high accuracy.
Structural Steel Fabrication with Mixed Reality
Authors: Blum Hannah B. , Kraus William
Published: September 2023

A new method to augment the quality control process of structural steel fabrication is proposed. Structural engineers and software engineers collaborate to produce a custom software to assist with quality control of fabricated steel before shipping the parts to the construction site. The process involves overlaying holograms onto the physical steel to display relevant information related to fit‐up work, which can include display of dimensions, streamlined information recording, and a guide to fabrication operations. The custom MR program can achieve a 1/16th inch (1.6 mm) accuracy between the holograms and the physical steel parts. The developed program is validated on two fabricated steel connections to demonstrate the features and the potential for implementing mixed reality into structural steel fabrication. Future planned developments are discussed.
Experimental testing of liner tray walls subjected to near field blast
Authors: Dinu Florea , Neagu Calin , Laszlo Robert , Ghicioi Emilian , Senila Mihai
Published: September 2023

Explosions produced in urban or industrial areas due to accidental or intentional detonation of high energy explosives (e.g., improvised explosive devices IED) are low‐probability but high‐impact events. If standoff distance from buildings or other constructions is small, explosions can cause structural failures and serious injuries or deaths of people. Preventing buildings from collapse is essential to minimizing casualties among occupants. However, experience has shown that even if the collapse is prevented, high number of injuries can result from fragments and flying debris generated by the non‐structural components or building envelopes. This risk could be minimized through appropriate design and selection of construction materials for most exposed elements (i.e., building envelopes). Although heavy/stiff systems were long considered appropriate to protect buildings against explosive threats, lighter and flexible systems are increasingly used for modern buildings. By allowing damage (but not fragmentation), the envelope system can provide predictable response, with minimal injuries in case of an explosion.

The study presents the results of full‐scale blast tests on liner tray walls attached to a steel frame building. Walls are tested against increasing blast charges until complete failure. The ultimate strength is given by the failure of the end fasteners, after large bolt hole elongations coupled with the pull‐through of the end fasteners.
Novel Hybrid Modular Construction System ‐ Structural Behaviour of Isolated Sub‐Frames
Authors: Milovanović Nemanja , Simões Rui , Tankova Trayana , Silva Luis Carlos , Craveiro Hélder , Costa Ricardo , da Silva Luís Simões
Published: September 2023

With the rising necessity for sustainable, economic and fast construction solutions, reliable modular construction systems are increasingly in demand. This paper presents a novel lightweight modular construction system, consisting of tubular columns and light‐gauge cold‐form steel profiles, where the beam‐to‐column connection is established by an innovative plug‐and‐play joint. The experimental campaign conducted on the full‐scale isolated sub‐frame configurations is reported, together with the recorded specimen behavior. The experimental results are compared with the numerical FEM estimations, leading to conclusions regarding the system's global behavior, its potential and the influence of the novel joint.
A generalised mechanical model for the characterisation of steel joints
Authors: Golea Tudor , Bodson Romain , de Ville de Goyet Vincent , Jaspart Jean‐Pierre , Demonceau Jean‐François
Published: September 2023

Component‐based mechanical models compliant with Eurocode 3 becomes a popular alternative to complex Finite Element (FE) analyses for characterising the behaviour of steel joints. However, several key aspects are not accommodated by the existing spring models, i.e., group mechanisms, component interactions, and the variation of the shear force on the height of the column web panel. This paper introduces an innovative mechanical model suitable for the characterisation of structural joints under generalised loading. The model relies on the principles of the Component Method and incorporates the features systematically disregarded in the classical spring models. This guarantees code‐compliant predictions, and by virtue of its universality, the model can be used for any loading protocol (bending moment ‐ sagging or hogging, axial force, bending moment + axial force). Conclusive evidence given by comparisons with experimental data and analytical results shows the compliance of the proposed model with the Eurocode 3 and proves its accuracy in predicting the actual behaviour of steel joints. The proposed modelling methodology allows integrating the model as a macro‐element in dedicated software, thus presenting promising perspectives for reliable and time efficient structural analyses.
Reassessment of Operating Engineering Steel Structures with the First Order Reliability Method and Bayesian Inference
Authors: Chowdhury Sharmistha , Arnold Robert , Kraus Matthias
Published: September 2023

Since the commencement of regulations and standards, the sustainability of civil engineering structures has been a recurrent issue for the construction industry and society at large. The practical design process of engineering structures, in accordance with national guidelines, addresses uncertainties related to the stochastic nature of parameters such as climate loads, structural materials, or model limits. These uncertainties are taken into consideration through initial probabilistic assumptions and safety factors. However, safety factors derived mathematically based on code‐driven presumptions often fail to accurately represent the unique conditions of an individual structure. Although the development of structural health monitoring (SHM) techniques allows for a significant reduction in the uncertainty of the action and resistance, the ability to transform monitoring information to reevaluate the design capacity of existing structures is limited at the practical level. This paper provides an example of how design can be enhanced by incorporating sensor data and using the Bayesian inference and First Order Reliability Method (FORM), tailored to accurately reflect the current structural condition.
Innovative hybrid coupled wall systems to resist seismic action – HYCAD
Authors: Das Rajarshi , Morelli Francesco , Zona Alessandro , Hoffmeister Benno , Vulcu Cristian , Degee Herve
Published: September 2023

This article summarizes the research carried out in the ongoing HYCAD project, which aims to improve the performances of a hybrid coupled wall (HCW) system for buildings in seismic areas, by further developing the HCW originally studied in the RFCS project INNO‐HYCO. This HCW system consisted of a reinforced concrete (RC) wall coupled with two steel side‐columns via steel coupling links. Encouraging outcomes were obtained such as: controlled post‐elastic ductile behaviour under medium‐ and high‐intensity earthquakes, suitable lateral stiffness, seismic energy dissipation concentrating in the easily‐replaceable steel links and very limited damage in the RC wall. However, advanced studies were required to bring this system into practice, addressing issues and develop advancements in the analysis, design, and detailing. This article summarizes the primary steps taken towards that purpose. Five new components were chosen in order to improve the performance of the HCW system: (1) Link‐to‐wall connections using post‐tensioned tendons; (2) Composite walls with encased steel profiles instead of a conventional RC wall; (3) Rocking coupled wall system; (4) Dissipating devices as links and (5) Precast double slab wall systems. Combining these components, four new HCW systems were developed, pre‐designed and analysed through numerical and experimental studies. Advanced yet simple techniques were proposed for the numerical analyses while test specimens are used to characterize local and global behaviour.
Efficient design of an office building as Steel/Timber hybrid – A case study
Authors: Anwaar Omer , Bello‐Garcia Micael , de Paula Filho J.H. Matias
Published: September 2023

With Climate change and environmental degradation, the climate emergency is just round the corner, to tackle this issue the European Union aims towards no net emissions of greenhouse gases by 2050. This would require designers to rethink the way buildings/structures are designed and most importantly with which material they must be designed.

The way forward is to have a sustainable design, with as little environmental impact as possible, but unfortunately the best materials in terms of environmental impact are not the cheapest. Hence, in this paper we would discuss how the two materials Steel and Timber maybe combined to form a hybrid structure – an Office building, taking advantage of steel's greater spanning strength and ductility and at the same time have a balanced carbon implication.

The study will also show, some of lessons learnt while comparing the two solutions, a complete timber design and a steel‐timber hybrid solution. Finally, a brief LCA analysis of solutions along with a steel‐concrete composite alternative will also be presented.
Linear buckling analysis in the design of bracket plates
Authors: Dowswell Bo , Vild Martin
Published: September 2023

Brackets are used to transfer loads in steel structures where the load is offset from the support. This paper will focus on T‐shaped brackets. Although such bracket plates are often used, a reliable design guideline is missing. Several design methods are presented and their accuracy is evaluated. Details of 86 experimental specimens from four previous research projects were compiled. Numerical models of these specimens were created, linear buckling analysis (LBA) and materially nonlinear analysis (MNA) were performed to determine the buckling force and inelastic strength, respectively. Both analyses are simple to use, robust and fast‐to‐converge methods. The purpose of this research was to develop practical design guidelines for the buckling strength of bracket plates that can be implemented with LBA/MNA. Investigated triangular bracket plates are supported on two sides, the legs, and free at one side, the hypotenuse. Buckling curve for this case is unknown. A reliability analysis is presented for the determination of critical load multiplier to avoid buckling. The results of MNA, which disregards buckling, can be safely used when the critical load multiplier, based on LBA, is equal to or greater than 4.
Hybrid fatigue crack propagation analysis using damage and fracture mechanics methods
Authors: Wu Weijian , Rasmussen Kim J.R. , Michel Alexander , Stang Henrik
Published: September 2023

Steel structures are frequently exposed to high‐cycle loading in which fatigue cracks initiate and propagate in the service life. The development of crack(s) will affect the structural integrity. In extreme cases, e.g., earthquakes and impacts, structures may be overloaded in several cycles or even a single loading cycle with the development of significant plastic deformation and macro cracks. Service loads, e.g., traffic and waves, will afterwards still be experienced in these damaged structures. The aforementioned two types of deformation are currently analyzed using damage and fracture mechanics methods, respectively. The cycle‐by‐cycle calculation and jump strategy relying on the Paris' equation, are employed for the low (including monotonic) and high‐cycle problems, using elastoplastic and linear‐elastic materials, respectively. The two calculation methods were developed independently, which presents a challenge in analyzing overloaded high‐cycle fatigue problems. This paper presents and executes a hybrid analysis using damage and fracture mechanics models for the single‐edge notch bend specimen. Either linear‐elastic or elasto‐plastic materials is employed in finite element simulations. The hybrid analysis with the combination of damage and linear‐elastic fracture mechanics shows the potential of a promising solution for assessing the fatigue behaviour of steel structures experiencing extreme loading and associated stepwise material damage. Some challenges are addressed in the combination of the ductile fracture followed by the high cycle fatigue calculation.
Towards an advanced fatigue assessment of welded steel joints with multiaxial stress states
Authors: Steinhoff Simon , Röscher Stefanie , Knobloch Markus
Published: September 2023

Advanced fatigue assessment methods, e.g. the Two‐Stage‐Model, are needed for the design of complex constructions or to accurately evaluate the remaining fatigue life of existing structures. The applicability of the Two‐Stage‐Model, including strain‐life approach and linear elastic fracture mechanics, was experimentally validated for uniaxial stress states only. However, typical construction details of steel and composite structures often exhibit a multiaxial non‐proportional stress state, which leads to variable principal stress values and directions. Comprehensive extensions of the Two‐Stage‐Model from uniaxial to multiaxial stress states are missing so far. This paper shows a study on advanced approaches that incorporate multiaxial stress states for both the crack initiation stage and the crack propagation stage, and their application in the Two‐Stage‐Model. For crack initiation, several approaches for the strain‐life approach, including multiaxial non‐proportional hardening and damage assessment based on critical planes are evaluated with respect to an application on the strain‐life approach. For the extension of the crack propagation stage, a computational procedure using XFEM and mixed‐mode approaches is presented.
Durable bolted joints for steel structures
Authors: Götz Frank
Published: September 2023

The article first discusses the basic behaviour of a preloaded and non‐preloaded bolted joint subjected to tensile or shear loads. The significance of the preload force for the bolted joint is explained. Causes for the loss of the preload force are described. In order to obtain the most durable bolted joint possible, measures against excessive loss of preload force are presented. Be it through appropriate design or manufacturing recommendations or through the use of additional securing elements. On the one hand, approved securing elements are presented and reference is also made to withdrawn standards and thus nonconforming securing elements.
Recycled CFRP Plate Retrofitting using Adhesive and TRS for Steel Girders
Authors: Komon Kazuki , Yamamura Akihiko , Sakano Masahiro
Published: September 2023

The retrofitting method using CFRP (Carbon Fiber Reinforced Plastic) plates was applied to a steel highway bridge in 2002 for the first time in Japan, where some of CFRP plates have been detected to be peeled from their ends, recently. CFRP plates are light‐weight and anti‐corrosive comparing with steel plates, while they have problems in the durability of adhesives bonding CFRP plates to steel plates. Currently, recycled CFRP plates have been developed for the environmental load reducing. Additionally, long sized CFRP plates are required to retrofit bridge members. In this study, the effectiveness of TRS (Thread Rolling Screw) used to connect the long‐size recycled CFRP plate end to the steel girder bottom flange with adhesives is investigated through static and fatigue loading tests using large size steel girder specimens. As a result, TRS can prevent long‐size recycled CFRP plates from peeling off under allowable stress static loadings, while the long‐size recycled CFRP plates connected by only adhesives without TRS peeled off from their ends. In fatigue loading tests, TRS can also prevent long‐size recycled CFRP plates from peeling, though fatigue cracks were developed from TRS holes under higher stress range.
Seismic behaviour of high‐strength steel welded flange‐bolted web connections
Authors: Hu Fangxin , Wang Zhan
Published: September 2023

Cyclic loading tests on two groups of welded flange‐bolted web connections employing 690 MPa high‐strength steels were conducted to quantify their plastic deformation and energy dissipation capacities under seismic loading conditions. The Q355 and Q690 beams in the two groups of specimens were designed with Class 1 and Class 3 cross‐sections, respectively; however, the Q690 columns in each group were designed nearly identical except for the thickness of their webs, which varied in order to identify the effect of shear panel strength on the connection seismic performance. Different beam‐to‐column flange welding types in each group were also considered. It was found that welding without backing bars should be used between Q690 beams and columns to accommodate some plastic rotation in the order of 0.01 rad in the beams, while a plastic shear distortion as high as 0.04 rad could be developed in Q690 web panels. This evidenced that those Q690 joint components could still sustain appreciable plastic deformations. In particular, Q690 web panels could be even qualified as high‐ductility class (DCH) in Eurocode 8.
Adhesive bonding of secondary steel components for offshore wind turbines
Authors: Albiez Matthias , Boretzki Jakob , Ummenhofer Thomas
Published: September 2023

Offshore wind turbines consist of the main components tower, nacelle and rotor blades. Additionally, numerous secondary components are connected to the primary structure. These include amongst others boat landings, platforms, cable protection tubes and corrosion protection systems. Usually, these elements are connected to the primary structure by welding or bolts. Both joining techniques reduce the fatigue performance of the primary structure by inducing geometric and/or metallurgical notches. In contrast, by fastening the secondary components by adhesive bonding, no geometric or metallurgical notches are induced in the primary structure. Furthermore, the bonding can be carried out directly on the coating. In contrast to welded or bolted joints, adhesively bonded joints require a differing geometry that allows large bonding areas. This paper highlights the results of experimental investigations regarding the load bearing behaviour of adhesively bonded secondary components under a combination of lateral load and bending varying different geometrical parameters.
Design fundamentals of demountable steel structures: from materials to members
Authors: Fan Junwei , Yang Lu , Liu Meiyu
Published: September 2023

The impact of greenhouse gas emissions, especially CO2 emissions, on the global environment is receiving more and more attention. Most countries around the world had reached a consensus to reduce carbon emissions after holding a series of climate conferences. In 2021, the buildings and construction sector accounted for around 37% of energy and process‐related CO2 emissions globally. To mitigate the CO2 emissions produced by the construction industry, the application of demountable steel structures that can be reused is a viable solution. This study investigated the design fundamentals of demountable steel structures that aims to reduce carbon emissions by reusing the main components of the steel structure. In this paper, the demountable reusability performance parameter γd of steel members is proposed and used for the reusable performance design of demountable steel members. An overview of the mechanical properties of steel materials under static and cyclic loading are presented as a basis for the reuse of steel structures. A brief review of existing forms of demountable steel connection joints is presented and the feasibility of reuse of demountable steel systems is explored.
Research on high‐performance steel structure with high‐strength steel column, ordinary‐strength steel beam, and low‐yield‐point steel BRB
Authors: Shi Gang , Zhao Huatian , Gao Yang
Published: September 2023

In order to reasonably make full use of the advantages of different steels and then achieve a steel structure with excellent seismic behaviour, the authors proposed novel triple grades hybrid high‐performance steel structures (TGHSSs) comprising high‐strength steel (HSS) columns, ordinary‐strength steel beams, and low‐yield‐point (LYP) steel buckling‐restrained braces (BRBs). The basic concept and expected advantages were introduced. To validate this concept, eight full‐scale single‐bay two‐storey TGHSS specimens were tested under cyclic loads, in which columns are of 460 MPa, 690 MPa, and 890 MPa HSSs, beams are of 345 MPa steel, and BRBs are of 100 MPa, 160 MPa, and 225 MPa LYP steels. Meantime, nine LYP steel BRB specimens were taken out and tested under uniaxial cyclic loads. Based on the experimental study, numerical simulation and parametric analyses on TGHSSs were further conducted, and a performance‐based design method was proposed. Results indicated that the TGHSSs featured a sequential yielding mechanism with excellent seismic performance. Specifically, the LYP steel BRBs yielded at first to dissipate seismic energy. Then, the ordinary‐strength steel beams developed plastic hinges at beam ends. At last, the HSS columns kept almost elastic or presented limited plasticity at column bases. This research proves such a high‐performance structure with a reasonable combination of high, ordinary, and low strength steels, whose advantages can be fully developed.
Large beam‐to‐column steel joint for the Dune Neutrino Experiment: experimental and numerical insights.
Authors: da Silva Luis Simões , Craveiro Hélder , Simões Rui , Martins Claudio , Conde Jorge
Published: September 2023

The new DUNE experimental facility for the study of neutrinos, hosted by the U.S. Fermilab, includes a massive steel cage fabricated out of S460 HL1100M profiles, where the corner joint between beams and columns is solved with a bolted flushed end plate. Although this joint typology is well described in the Eurocode, the size and internal forces of this case are out of the common experimental range. Thus, a real‐scale test of the joint has been carried out at the University of Coimbra. The results were used to validate high‐quality FEA models, which accurately reproduced the behavior and allowed further insight into the joint component characterization. Comparison with the Eurocode design values show a good agreement, validating the application of the component method to very large joints.
Welding under service conditions ‐ Influence of different boundary conditions during welding
Authors: Begemann Florian , Unglaub Julian , Thiele Klaus
Published: September 2023

Steel structures, such as bridges, must be continuously maintained. Due to increasing traffic loads, design and execution shortcomings, many steel bridges are subject to various types of damage, such as cracks. The bridges must be maintained by crack removal and re‐welding the cracks. During this work, the bridge is closed for traffic in order to suppress the crack flank movement during welding. As a result, traffic loads on other routes are higher, which increases further damage on detour routes and subsequently additional welding work and costs on these structures. Therefore, the aim is to provide a method that allows welding work on steel structures under running traffic, respectively under cyclic loads. First, measurements at a representative steel bridge were conducted to derive gap opening parameters of amplitude and frequency for welding tests under cyclic loads. Monitoring cracks shows that the crack behavior is complex and the description of the force redistribution during welding is a challenge. In order to quantify the influence of different boundary conditions during welding on weld quality and fatigue, experimental investigations were carried out under displacement control only and force control only. For both, the weld quality and the fatigue strength was comparable to the standard requirements, so that welding under service conditions is possible under certain aspects.
Track‐Bridge Interaction: Influence of Transition Zone on the Stability of Continuous Welded Rail
Authors: Mubarack C K Ali , Upadhyay Akhil
Published: September 2023

Realization of high‐speed rail track demands continuous welded rail (CWR) to be laid on bridges without providing special expansion joints. In India, the existing rail bridges must be evaluated for their suitability for upgradation to CWR. CWR Inherently develops axial stress on account of the surrounding temperature changes. CWR in track‐bridge transition zone is subjected to additional stress and displacements as a result of track‐bridge interaction (TBI). Longitudinal thermal loading is a major source of rail stress and substructure forces due to TBI. Also, TBI results in accumulation of large compressive stress in transition zone. Further, the tamping effect in the transition zone by passing vehicles due to sudden change in vertical stiffness weakens the transition zone ballast. CWR is a slender steel element prone to buckling under large compressive stress. A numerical model is developed for track bridge interaction phenomenon in SAP2000 considering the aspect of CWR track buckling. In this study, the developed model is utilized to perform nonlinear buckling analysis to assess the influence of change in ballast stiffness on CWR stability in transition zone. Also, the influence of missing ballast contact raising from ballast subsidence locally in the transition zone was investigated. A single span simply supported steel bridge is considered. Longitudinal thermal loading is considered in this study. CWR supported on the ballasted track is considered. Material Nonlinearity associated with ballast is considered. Maintenance of CWR track is found to play a key role in track stability as the loose ballast or missing of ballast underneath the rail sleeper is to introduce discontinuity in CWR track support and reduces the critical buckling temperatures of the track considerably. Overall, this study contributes to the understanding of track‐bridge interaction and the stability of CWR in the transition zone.
Serial Uniqueness: Strengthening Standard Steel Profiles with WAAM Technology
Authors: Kloft Harald , Schmitz Linus Paul , Babovic Neira
Published: September 2023

Wire‐and‐Arc Additive Manufacturing (WAAM) is based on the well‐known welding technique in which an electric arc is used as a heat source to melt a metal wire. The technology finds its application, among else, in the construction industry, where steel wire is the chosen feed material. Different scales of structural components and elements can be manufactured using WAAM, such as steel joints and pedestrian bridges. Robot‐assisted control of the layer build‐up allows for freedom in the design of structural elements. In this paper, the authors propose a hybrid manufacturing method to combine industrial serial processing with individualised additive manufacturing based on the local stress distributions and force‐flows. The method is validated on the set of five different demonstrators that tackle different local structural issues through different design solutions for local strengthening while exhibiting particular manufacturing constraints characteristic for a workspace confined by flanges of rolled I‐profiles.
Generic method of local thickening in shell element FEM models for orthotropic bridge decks
Authors: Rodenburg Jorrit D. , Hengeveld Sjoerd T. , Wijnbeld Bas M.M. , Maljaars Johan
Published: September 2023

This paper presents a method of estimating the hot‐spot stress in orthotropic bridge decks (OBD) using a shell Finite Element (FE) model, in which local thickening is applied around the welded. The dimensions of the area of local thickening are a function of the weld throat thickness and the plate thickness. A comparison of this method with 3D solid element FE models is presented for various fatigue sensitive details. The comparison is carried out for OBD with trapezoidal stiffeners, both with continuous stiffeners through crossbeams and with stiffeners welded in between crossbeams. It is concluded that the accuracy of estimating the hot‐spot stress with a shell element model using local thickening is significantly higher as compared to a conventional shell element model without thickening. The method of local thickening is adopted in the new prTS 1993‐1‐901. This paper functions as the background to this technical specification.
A triaxiality‐dependent fracture model for hot‐rolled sections made of S355 steel
Authors: Kastiza Pelagia , Skalomenos Konstantinos , Theofanous Marios
Published: September 2023

Fracture at net areas of steel sections often leads to premature failures of steel members, especially in the region of joints (bolted connections). This study develops a fracture model for hot rolled S355 steel for enabling a better understanding of the ultimate behaviour of steel sections through numerical simulations using the general‐purpose finite element software ABAQUS. Monotonic tensile tests are conducted on traditional dog‐bone plate specimens with a uniform cross‐section and notched plate specimens extracted from hot‐rolled I‐beams. Two material thicknesses and three notch radii per thickness are considered thus obtaining equivalent plastic strains at fracture over a wide range of stress triaxialities. The experimental fracture displacement is used as a threshold for the determination of the average stress triaxiality – equivalent strain history at the critical location (fracture initiation) of each plate model. Using regression analysis, an exponential approximation of the fracture locus is proposed to correlate the average stress triaxiality for a given equivalent plastic strain at fracture. The proposed model is then used to predict fracture initiation of unnotched tensile coupons and steel plates with a bolt hole in their centre extracted from the same steel sections. The test results are in good agreement with the numerical predictions thus demonstrating the efficiency of the proposed method.
Tensile Behavior of Anchored Stainless Steel T‐Head Blind Bolts within Concrete‐Filled Steel Square Tubes
Authors: Li Ying‐Lei , Huang Ming‐Xian , Zhao Xiao‐Ling
Published: September 2023

Based on a recent review on blind bolted connections to concrete‐filled steel tubes, there is a need to improve the performance of anchored blind bolts in such composite connections. This paper presents a study on the pull‐out behavior of anchored blind bolts under applied tensile load in terms of stiffness, yield strength, ultimate strength and load‐displacement response. A finite element (FE) model with concrete damage plasticity model was developed for parametric study. Effects of key parameters, such as concrete strength, bolt grade, embedment length, tube thickness and tube grade, on the tensile behavior of the connection were studied to identify the key parameters influencing the behavior. Finally, a predictive model based on component method was proposed to estimate the structural behavior of the blind‐bolted connections.
Elastic behavior of riveted double angle connections in tension
Authors: Sarou Lynita , Couchaux Maël , Hjiaj Mohammed , Sire Stéphane , Douroux Jean‐François
Published: September 2023

T‐stubs and L‐stubs loaded in tension are generally assumed in contact with a rigid foundation. The prying force and stiffness of these components depend on this hypothesis. For double web angle riveted connections, the angle rests on deformable beam/column web. The objective of the present paper is to take into account the effects of this deformability on the development of the contact area, the rivet forces and the tensile stiffness. An enhanced theory of beam in contact with a tensionless Winkler foundation is adopted in the contact and lift‐off areas. The axial and bending flexibilities of rivets are also considered. A numerical analysis is also performed with ANSYS in order to validate the analytical model. A sensitivity study is conducted on the influence of the thickness of the horizontal leg. The analytical and the numerical results are in good agreement, which confirms the accuracy of the proposed mechanical model.
NMR Diffusometry and a (Random) Journey Across the World
Authors: Galvosas Petrik
Published: September 2023

Samples relevant to fields such as chemical engineering, soft matter research, environmental studies and biology can be studied with respect to their material properties by characterizing the molecular mobility of the sample itself or of fluids interacting with the sample. This mini review aims to illustrate the versatility and power of NMR diffusometry in obtaining relevant material information provided by diffusion for a selection of different samples.
Feasibility of improving dust removal efficiency of fly ash fine particles for coal‐fired power plants
Authors: Li Haisheng , Yao Jie , Xu Ziyin , Zhou Hui , Chen Yinghua , Feng Weigang
Published: September 2023

As solid waste of coal‐fired power plants, atmospheric environmental pollution is caused by fly ash during transportation. The purpose of this study was to improve the dust removal efficiency of fly ash fine particles by electrocoagulation and obtain reasonable operating parameters. The effects of particle concentration, gas velocity, AC frequency, and voltage on particle electrocoagulation efficiency were studied through the establishment of a discrete element soft sphere calculation model, and reasonable electrocoagulation operation parameters were obtained. The dust removal process was evaluated according to the particle number concentration, electrocoagulation efficiency, and particles microscopic characteristics due to the dust removal experiments of fly ash by electrocoagulation. The results demonstrated that increasing particle concentration, reducing gas velocity, and selecting reasonable AC frequency and voltage were effective to improve the real‐time electrocoagulation efficiency and its stability. Under the suitable conditions: voltage of 3 kV, airflow velocity of 5 m s–1, particle concentration of 30 mg m–3 and AC frequency of 100 Hz, the electrocoagulation efficiency was higher than 40%. The electrocoagulation was effective to improve the dust removal efficiency of fly ash fine particles with a relative humidity of air below 70% and ambient temperatures above 20°C.
Structural Modification of the Natural Product Valerenic Acid Tunes RXR Homodimer Agonism
Authors: Zaienne Daniel , Isigkeit Laura , Marschner Julian A. , Duensing‐Kropp Silke , Höfner Georg , Merk Daniel
Published: September 2023

Retinoid X receptors (RXR) are ligand‐sensing transcription factors with a unique role in nuclear receptor signaling as universal heterodimer partners. RXR modulation holds potential in cancer, neurodegeneration and metabolic diseases but adverse effects of RXR activation and lack of selective modulators prevent further exploration as therapeutic target. The natural product valerenic acid has been discovered as RXR agonist with unprecedented preference for RXR subtype and homodimer activation. To capture structural determinants of this activity profile and identify potential for optimization, we have studied effects of structural modification of the natural product on RXR modulation and identified an analogue with enhanced RXR homodimer agonism.
Racial differences in serum chemokines in prostate cancer patients
Authors: Karan Dev , Wick Jo , Dubey Seema , Kumar‐Sinha Chandan , Siddiqui Javed , Kunju Lakshmi P. , Iczkowski Kenneth A. , Chinnaiyan Arul M.
Published: September 2023

Background

This study aimed to understand the differential levels of inflammatory chemokines in association with higher prostate cancer incidence and mortality in African American (AA) men than in Caucasians (CA).

Methods

The authors used a chemokine assay to simultaneously measure 40 chemokines and cytokines levels in the serum of preoperative prostate cancer patients and healthy controls of AA and CA races. Selected chemokines (CXCL2, CXCL5, and CCL23) serum level was validated in 211 serum samples from prostate cancer patients and healthy controls. Differential expression of CXCL5 and CCL23 was analyzed using immunohistochemistry in a representative cohort of prostate tumor tissues of AA and CA races.

Results

Race‐specific comparisons from 211 serum samples showed significantly higher levels of CXCL2 (control: 3104.0 pg/mL vs. cancer: 2451.0 pg/mL) and CXCL5 (control: 5189.0 pg/mL vs. cancer: 5459.0 pg/mL) in AA men than in CAs (CXCL2; control: 1155.0 pg/mL vs. cancer: 889.3 pg/mL, and CXCL5; control: 1183.0 pg/mL vs. cancer: 977.5 pg/mL). CCL23 differed significantly within and between the races with a lower level in AA cancer cases (454.5 vs. 966.6 pg/mL) than healthy controls (740.5 vs. 1263.0 pg/mL). Patient age, prostate‐specific antigen, or Gleason scores were not significantly associated with these chemokines. Immunostaining for CXCL5 and CCL23 in a representative cohort of archival prostate tissues displayed significantly higher CXCL5 in prostate tumors than in adjacent benign tissues, whereas CCL23 was nondetectable in most of the analyzed tumor tissues.

Conclusion

Lower levels of CCL23 in AA prostate cancer patient sera and tumor tissues and high CXCL2 and CXCL5 may contribute to aggressive prostate cancer, as often seen in AA men. The disproportionate levels of serum chemokines associated with race warrant further exploration to improve equitability in precision oncology to benefit prostate cancer patients.
Protective effect of miR‐18a in resected liver metastases of colorectal cancer and FOLFOX treatment
Authors: Franz Clemens , Jötten Laila , Wührl Michael , Hartmann Sibylle , Klupp Fee , Schmidt Thomas , Schneider Martin
Published: September 2023

Background

Colorectal cancer ranks second in terms of cancer associated deaths worldwide, whereas miRNA play a pivotal role in the etiology of cancer and its metastases.

Aims

Studying the expression and cellular function of miR‐18a in metastatic colorectal cancer and association to progression‐free survival.

Methods and Results

Colorectal liver metastases (N = 123) and primary colorectal cancer (N = 27) where analyzed by RT‐PCR and correlated with clinical follow up data. Invasion and migration assays were performed with the liver metastatic cell line LIM2099 after miR‐18a knockdown. Cell viability under FOLFOX treatment and knockdown was measured. We found that the expression of miR‐18a was increased 4.38‐fold in liver metastases and 3.86‐fold in colorectal tumor tissue compared to healthy liver tissue and colorectal mucosa, respectively (p ≤ .001). Patients with a high miR‐18a expression in liver metastases had a progression‐free survival (PFS) of 13.6 months versus 8.9 months in patients with low expression (N = 123; p = .024). In vitro migration of LIM2099 cells was reduced after miR‐18a knockdown and cell viability was significantly increased after miR‐18a knockdown and treatment with folinic acid or oxaliplatin. Subgroup analysis of PFS revealed significant benefits for patients with high miR‐18a expression receiving 5‐FU, folinic acid or oxaliplatin.

Conclusions

High expression of miR‐18a in colorectal liver metastases might have a protective effect after resection of metastases and FOLFOX treatment regarding PFS.
The influence of partial gastrectomy for gastric cancer on the spontaneous disappearance of Helicobacter pylori: A single‐center prospective study
Authors: Yanagawa Senichiro , Fujikuni Nobuaki , Tanabe Kazuaki , Nakahara Masahiro , Noriyuki Toshio
Published: September 2023

Background/Aims

Helicobacter pylori (HP) eradication is recommended after endoscopic treatment of early gastric cancer (EGC). Cases of spontaneous HP resolution after partial gastrectomy due to environmental changes have been reported; however, there is no evidence for the efficacy of HP eradication in suppressing carcinogenesis and also no reports on the natural history of HP after partial gastrectomy in gastric cancer (GC). To report the natural history of HP in patients with GC and HP infection after partial gastrectomy.

Methods and Results

We prospectively studied the rate of spontaneous disappearance of HP after partial gastrectomy in patients with GC. From April 2016 to May 2020, 80 patients underwent partial gastrectomy, including 9 cases of proximal gastrectomy (PG), and 71 cases of distal gastrectomy (DG). The presence of HP was confirmed in the stool antigen test 1 year after operation, HP infection persisted in 46 patients (57.5%) and disappeared in 34 patients (42.5%). In univariate analysis, only proton pump inhibitor (PPI) use was a significant contributing factor for the spontaneous resolution of HP infection, especially in the DG group. However, there was no difference in the rates of HP disappearance between Billroth‐I and Roux‐en‐Y reconstructions in the DG group.

Conclusion

The HP spontaneously disappeared in 42.5% of the GC patients within 1 year after partial gastrectomy. Further investigation in a larger cohort is needed to elucidate the underlying mechanisms.
Distribution of hand function by age in individuals with Rett syndrome
Authors: Neul Jeffrey L. , Benke Tim A. , Marsh Eric D. , Lane Jane B. , Lieberman David N. , Skinner Steven A. , Glaze Daniel G. , Suter Bernhard , Heydemann Peter T. , Beisang Arthur A. , Standridge Shannon M. , Ryther Robin C. C. , Haas Richard H. , Edwards Lloyd J. , Ananth Amitha , Percy Alan K.
Published: September 2023

Objective

We aimed to determine the longitudinal distribution of hand function skills in individuals with classic Rett syndrome (RTT), an X‐linked dominant neurodevelopmental disorder, and correlate with MECP2 variants.

Method

We conducted a longitudinal study of 946 girls and young women with typical RTT seen between 2006 and 2021 in the US Natural History Study (NHS) featuring a structured clinical evaluation to assess the level of hand function skills. The specific focus of this study was to assess longitudinal variation of hand skills from age 2 through age 18 years in relation to specific MECP2 variant groups.

Results

Following the initial regression period, hand function continues to decline across the age spectrum in individuals with RTT. Specific differences are noted with steeper declines in hand function among those with milder variants (Group A: R133C, R294X, R306C, and C‐terminal truncations) compared with groups composed of individuals with more severe variants.

Conclusions

These temporal variations in hand use represent specific considerations that could influence the design of clinical trials that test therapies aiming to ameliorate specific functional limitations in individuals with RTT. Furthermore, the distinct impact of specific MECP2 variants on clinical severity, especially related to hand use, should be considered in such interventional trials.
An Open‐Field‐Based Unimodal Object Recognition Test (OF‐UORT) for Assessment of Chronic Stress Effects on Visual and Tactile Unimodal Cognition in Mice
Authors: Wang Chi , You Shi‐Wei , Wang Xiao‐Dong
Published: September 2023

The open field (OF) test is a widely used behavioral assay in animal studies to assess locomotion, emotion, and cognition. In open‐field‐based object recognition tasks, the open arena is equipped with combinations of objects to allow the examination of various aspects of learning and memory. In this article, we provide a protocol for open‐field‐based unimodal memory tests that assess tactile or visual unimodal cognitive behavior in mice. These tests do not require mice to be restricted from eating or drinking and do not involve aversive stimuli, such as electric shock, high‐decibel sound waves, bright light, or forced swimming. Inside the apparatus, mice can freely and spontaneously explore the objects and the environment. Sniffing of, or direct contact with, objects is considered a cognitive exploration of the objects, and the timing and number of such behaviors can be recorded. During the acquisition phase, two identical objects are provided. After an intertrial interval, the retrieval phase is initiated, during which one object is replaced with a new object that is different from the previous one. Decorative clear domes are used prevent direct tactile contact with the objects, whereas infrared illumination is used to block visual information from the objects. By alternating the access to visual or tactile features of the objects in the acquisition and retrieval phases, the experimenters can assess visual or tactile unimodal cognition. Here, we describe our own instrumentation and application for experiments, and demonstrate that the modified device is capable of testing visual or tactile unimodal cognition in mice. Although easy to perform, this task/test can accurately reflect unimodal cognitive performance in mice, which can provide solid and reproducible data support to related studies. © 2023 Wiley Periodicals LLC.

Basic Protocol 1: Validation of the open‐field‐based unimodal object recognition test

Basic Protocol 2: Evaluation of chronic stress effects on unimodal cognition using the open‐field‐based unimodal cognitive test