bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automatic food and beverage authentication and adulteration detection by classification hybrid fusion
Authors: Kalivas John H. , Lemos Tony 
Published: September 2021

AbstractA rising problem in the food industry is identifying the origin and/or purity of food products, and classification is often used for the identification. The process involves determining whether a food sample is similar to a collection of samples characterizing a known food product (is the food product a class member?). However, classification requires the analyst to face a myriad of complex decisions. With modern instrumentation, classification based on conventional data fusion processes increases the assortment of decisions. Typically, testing food products without data fusion involves (1) selection of an instrument or measuring device, (2) determining suitable measurement variables, for example, sensors or wavelengths for spectral data, (3) data preprocessing optimization, and (4) selection of a classification method followed by identifying the best tuning parameter setup for that classifier. If data fusion is desired, optimization of combined variations of (1)–(4) is required. This paper overviews a recent approach that simplifies data fusion decisions for food authentication and adulteration classification purposes. This unique self‐optimized fusion method avoids the confounding decisions by simultaneously evaluating any number of permutations of (1)–(3) in combination with a collection of non‐optimized classifiers based on respective tuning parameter windows for (4). Self‐optimization is obtained by using the sum of ranking differences (SRD) to form the final fused class membership decision for each new food test sample where the SRD was automatically optimized using a receiver operator characteristic (ROC) curve. The simple automatic SRD hybrid fusion/ROC curve process removes the myriad of subjective decisions imposed on the analyst and increases food classification reliability. Results are demonstrated with three datasets.
Threaded bar stiffening in semi‐rigid beam to column joints
Authors: Reinosa J.M. , Loureiro A. , Gutiérrez R. , López M. 
Published: September 2021

AbstractSemi‐rigid bolted beam‐to‐column connections are widely used for multi‐storey frames. The column section required to resist the force transmitted by the bolts at the beam tension flange level can be reduced by provision of column flange reinforcement. Welding stiffening is often used in spite of several economic and performance disadvantages. This paper presents a numerical study on the use of threaded bars intended to provide local column reinforcement in semi‐rigid angle beam‐to‐column connections, avoiding conventional welded plate stiffening. 3D Finite Element models were developed to analyze the effect of the threaded bars in different joint configurations. The study results show that the use of threaded bars in semi‐rigid bolted joints reduces the stress level in the panel and can be an interesting alternative to welded stiffeners to reinforce the column, leading to significant savings.
Weathering Impacts on the Tightening Behaviour of HV/HR‐Bolting Assemblies for Preloading
Authors: Stranghöner Natalie , Jungbluth Dominik , Abraham Christoph 
Published: September 2021

AbstractIn order to secure a specified preload level, suitability tests for preloading of HV and HR high‐strength structural bolting assemblies according to EN 14399‐4 and EN 14399‐3 are mandatory according to the specifications given in EN 14399‐2.However, in EN 14399‐2 and EN ISO 16047 actual working conditions and processes on the construction site are disregarded: influences of high and low temperatures as well as storage conditions under changing wet/dry conditions, both summarized as weathering impacts, are not covered in the suitability test. Consequently, this leads to a lack of knowledge regarding the effect of weathering impacts on the basic preloading and tightening behaviour of HV and HR bolting assemblies. From practical experiences it is known that different extreme temperature conditions as well as moisture on the threads of the bolting components have an influence on the tightening behavior, which led to failures of the bolting assemblies during the assembly in the past.The presented contribution intends to provide a first insight into the influence of weathering impacts on the tightening behaviour of HV‐ and HR‐bolting assemblies for preloading on the basis of tightening tests of HV and HR bolting assemblies under various temperatures (‐20 °C, +23 °C, +50 °C) and moisture conditions (dry, hoarfrost, little direct/indirect rain impact, changing dry/wet condition etc.).
Experimental study on tensile behavior of blind bolt
Authors: Jiang Yunhan , Li Guoqiang , Chen Chen , Wen Ce , Zhang Sixian 
Published: September 2021

AbstractAs blind bolt can be installed only on one side, it has the advantage that ordinary high strength bolt doesn't have in the application of closed section connection. In this paper, the existing non‐standardized sleeve high strength blind bolt (NSHSBB) is improved, and standardized sleeve high strength blind bolt (SSHSBB) and small diameter blind bolt are put forward, and the tensile tests of two kinds of bolts of 8.8 and 10.9 grades with diameters of 12mm, 16mm and 20mm are carried out. It is clear that the tensile process of blind bolt can be divided into three stages by analyzing it, and the tensile stiffness and boundary loads of three stages are obtained, that is: steel plate separation load, bolt yield load and tensile bearing capacity of blind bolt. By adjusting the installation torque, the separation loads of steel plate under different torques of each blind bolt are obtained, and the relationship between the pre‐tension and the separation load of steel plate and the two stages stiffness is clarified by deducing formulas. According to the above results, the recommended installation torque and pre‐tension of blind bolt are given. The bearing capacity of blind bolt is equal to that of high strength bolt of the same grade, and its stiffness is lower than that of high strength bolt, which has little influence on the rotational stiffness of the joint is very small yet, based on the analysis.
Experimental study of slip‐resistant connections under cyclic load
Authors: Fric Nenad , Mišković Zoran , Budjevac Dragan , Veljković Milan 
Published: September 2021

AbstractThe slip‐resistant shear connections with preload bolts have traditionally use in the steel structures exposed to cyclic / fatigue loading or in the cases when the bolt slipping or connection deformations should be restricted. Hence, the shear load is transferred through the friction surfaces rather than the contact between bolt surface and hole. The main influencing parameters determine the connection slip resistance are the friction between the contact surfaces and the level of preload in the bolts. This paper presents an experimental study of preloaded bolted connections under cyclic load. Experiment was performed on double lap shear connections using high strength bolts and lock bolts, both M20 of grade 10.9. The steel plates used in experiment are grade S355JRG2. Sandblasting was performed using quartz sand as the abrasive after which the zinc‐silicate coating was applied on plate surfaces. To address the required pretension force in the bolts, the strain gauge method was employed. All strain gauges were calibrated. Six specimens were exposed to cyclic loading after monitoring initial and short‐term losses of pretension forces in the bolts. The main objective of the presented study is to investigate the influence of the cyclic load on the losses of pretension force in high strength bolts and lock bolts. The results of comparative experimental analysis are presented and discussed.
Behaviour of Steel Tube Knee Joint Inserts used in Aluminium Portal Frames
Authors: Skejic Davor , Curkovic Ivan , Garasic Ivica , Cudina Ivan , Doksanovic Tihomir 
Published: September 2021

AbstractUsually, prefabricated aluminium halls use portal frame structures with a high strength steel tension tie element. Due to the high reduction of aluminium strength induced by welding, aluminium joints of prefabricated halls are almost exclusively formed using bolts in combination with steel reinforcements. The most convenient type of reinforcement is a steel tube knee joint insert. In these joints, the transmission of forces is realized partially through bolts and partially through a complex contact mechanism between aluminium members and the steel tube knee joint insert. Detailed overview of the behaviour of such joints is still unknown and simple expressions for the assessment of their behaviour are lacking. With that in mind, as a first phase of the research, laboratory tests of steel tube welded knee joints with bolted tie element were performed under the application of static loading. Numerical simulations in ANSYS were performed to enable a deeper insight into the complex interaction of different joint components. Due to the limitations of laboratory equipment and the fact that only a ‘rigid’ tie element (circular tube) was utilized in tests, numerical simulations were also applied to extend experimental results and include different, more realistic, levels of axial stiffness of the tie element. Obtained structural properties of the tested joint type are provided and discussed regarding the advancement of understanding underlying behaviour parameters and outlining further research phases.
Numerical analysis of ring flange connection with defined surface area
Authors: Cheng Lu , Xin Haohui , Veljkovic Milan 
Published: September 2021

AbstractRing flange connections with preloaded high strength bolts are most commonly used to connect two segments of steel tubular towers. Behaviour and durability of ring flange connections is influenced by various factors, including stiffness of ring flanges, fabrication and execution imperfections, welding technology and welding details of the ring flange/segment connection, type of bolts, pretension technique and control of accomplished pretension force in bolts. This paper focuses on ring flange connections with defined contacts compared to the “full ring flange connection”. No imperfections are considered. Behaviour of the ring flange connections is investigated by advanced finite element analysis (FEA). The realistic geometry of bolted connection, ductile damage material model and element removal are used in the advanced FE model with explicit numerical solver. In addition, the influence of two types of high strength bolts, fully‐threaded and partial‐threaded bolts, on the mechanical behaviour of connections is considered. The failure modes and tensile stiffness are compared using different analytical models. Finally, recommendations for calculation of the tensile resistance of the connection and the bolt force with defined surface area are provided.
Distribution of the friction coefficient in the tension connections by the HV set using the combined method
Authors: Dubiel Tomasz , Osetek Mirosław , Majka Monika 
Published: September 2021

AbstractThe use of bolts in steel structures nowadays is one of the cheapest, fastest and easiest solutions for joining elements. HV high‐strength bolts used in tension connections are a special type of fasteners covered by supervision beginning with the selection of the material from which they will be made through the production process and quality confirmation, ending with clearly defined assembly requirements.The tests were focused on two assortments of M16 and M24 bolt assemblies made according to EN 14399. A test of the suitability of the connection was performed, expanding it with tests of the coefficient of friction on the bolt thread and between the nut head and washer according to EN ISO 16047. The dynamic joint load tests showed that the distribution of the coefficient of friction on the thread and between the nut and the washer affects the degree of tension through the preloading force.Tensile tests were carried out on the both aforementioned assortments. The determined yield point of the bolt was analyzed, which was referred to the stress causing plastic deformation in the test of connection suitability. Bolts in two systems of forces were compared with each other (simple ‐ stretching and complex ‐ stretching and torsion) and the difference between them was shown. Based on the correlation of results from both tests, the importance of the K‐factor on the mechanical properties of the HV set was emphasized. The dependence of the K‐factor on the coefficients of friction in a bolted joint has been demonstrated.HV high‐strength bolt sets consider assembly procedures using a combined method according EN 1090‐2. Cases of exceeding the yield point of the bolt during assembly and permanent deformation of the fastener have been shown. The scope of assembly was determined in the elastic range and the transition to the range of plastic deformations. Again, reference was made to the coefficient of friction and its effect on the difference in the obtained preloading force leading to risky assembly in the plastic range.
Non‐destructive damage detection on welded threaded bolts based on electromechanical impedance spectra
Authors: Sahm Daniel , Pak Daniel , Fritzen Claus‐Peter , Dreisbach Anna‐Lena , Dietrich Gerhard , Yokaribas Volkan 
Published: September 2021

AbstractWithin a research project carried out at the Department of Civil Engineering and the Department of Mechanical Engineering of the University of Siegen, a new monitoring method for non‐destructive damage detection on bolts was developed and tested according to its applicability on real life structures. The so‐called EMI‐method is based on the measurement of electromechanical impedance spectra, which change with varying structural states and thus allow for a condition assessment.Structures vibrate in a combination of their natural modes, which can provide information about their structural condition. Their modal characteristics are system‐inherent quantities and are governed by geometry, system stiffnesses and mass allocation. If a system parameter changes, e.g. the bending stiffness of a bridge, this is reflected in the vibration analysis and the modal characteristics. To identify the modal characteristics of civil engineering structures, these are excited and the system response is measured. This principle is also used for damage detection by means of electro‐mechanical impedance spectra (EMI). The observed system‐inherent quantity is the frequency‐dependent mechanical impedance Zs(ω) of the structure. The method is based on the idea that the mechanical impedance of a structure or component to be measured changes as a result of damage (or loss of prestress in the case of bolts) and thus these changes can be detected.In the project, investigations were carried out on steel plates with orthogonally welded threaded bolts, which are used, for example, as fasteners for rail supporting points on bridges. Research objectives were on one hand the detection of the prestress stage and on the other hand the detection of fatigue damage in the weld seam. Within the scope of the project, it has been investigated to what extent a change of the prestressing load can be reliably detected by means of the EMI method. Furthermore, the influence of damage to the bolt on the impedance spectra was investigated.
Experimental investigations on rolled angle sections reinforced with CFRP plates
Authors: Vlachakis Konstantinos , Reygner Sebastien , Tibolt Mike , Vayas Ioannis 
Published: September 2021

AbstractTelecommunication or power transmission lattice towers may be in need of strengthening due to enhanced operational requirements of 5G systems or extension and upgrading of existing power lines. The members of such towers are mostly angle sections that are conventionally strengthened by a second profile to become a built‐up member. As an alternative, hybrid strengthening of tower angle members with carbon fiber reinforced polymers (CFRP) plates may be employed. The present paper provides experimental tests on hybrid angles that include bending tests and compression tests carried out in the frame of the RFCS research project ANGELHY. In 3‐point bending tests the specimens were subjected to loading along the principal and the geometric axes. They allow the definition of the bending capacity and the development of appropriate design rules for hybrid cross‐sections. The compression tests were performed on specimens of different length and loading eccentricity, with FRPs attached to one or both sides of the legs. Important parameters influencing the buckling capacity were detected.
Experimental and numerical analysis of three‐point bending tests of steel beams with web holes
Authors: Matos Rui , Craveiro Hélder , Lopes Tiago , Zanon Riccardo , Tibolt Mike 
Published: September 2021

AbstractSteel profiles are commonly used as filler‐beams for composite decks of road and railway bridges. The filler beams are encased in a concrete slab with reinforcement bars parallel and transversal to the steel profile. To ensure the passing of the transversal reinforcement rebars, the web of the filler‐beams must be previously drilled with a suitable diameter. The closely spaced steel beams and the reinforced concrete act compositely in the longitudinal direction. In current practice, steel profiles are cambered in the vertical plane to compensate the deflection of the steelwork under self‐weight of the deck, permanent loads and equivalent concrete shrinkage load.In this investigation a set of experimental tests was undertaken on simply supported beams aiming to reproduce the precambering procedure of steel profiles with web holes. In the structural tests, the main goal was to assess the overall performance of the steel element with holes on the web for transversal reinforcement, relating the different camber values with the applied load and observed ovalization of the web holes. Material mechanical characterization was also undertaken in this investigation.Based on the experimental results, finite element models were developed and calibrated, aiming to undertake extensive parametric studies to gather relevant data for the definition of a systematic procedure for precambering of steel beams with holes on the web for transversal reinforcement.
Using full‐scale tests results for designing of steel telecommunication towers
Authors: Szafran Jacek 
Published: September 2021

AbstractThe main goal of this paper is to provide recommendations for designing state‐of‐the‐art and lightweight steel lattice telecommunication towers which offer the highest possible load‐carrying capacity. The design rules presented in the paper are based on experimental results obtained for two independent tower structures. Full‐scale facilities, namely 42‐m‐high towers were tested. Stresses in compressed legs of lower segments of the towers, displacements of their tops, and, notably, failure mechanisms are analyzed. Technical solutions including additional equipment, such as service platforms and cable and access ladders, are also considered. Means of reinforcing tower structures with a focus on modifying buckling strength of legs and diagonal bracings are also discussed and justified.
Buckling analysis of tower shells under patch loading for self‐erecting wind energy plants
Authors: Nikesch Philip , Pak Daniel , Korte Sebastian 
Published: September 2021

AbstractTo achieve a higher performance level and lower erection costs for wind turbines in the future, a concept for the automatic erection of a wind turbine with a hybrid tower was investigated in the FOSTA research project P1392. The tubular steel tower is lifted through the lattice tower using a strand lifting system and stabilized during this lifting process with the help of hydraulic cylinders arranged in two levels in the transition piece. This stabilization results in a transverse pressure acting on the tower shell, which does not occur in the load cases during operation, but only in the construction state. In this paper, the transverse forces (patch load) acting on the tower are investigated, whereby different system states are considered.
Experiments on sheathed cold‐formed steel beam‐columns
Authors: Kyprianou Constantinos , Kyvelou Pinelopi , Gardner Leroy , Nethercot David A. 
Published: September 2021

AbstractAn experimental study on sheathed cold‐formed steel C‐lipped columns (studs) with service holes in the web subjected to compression and major axis bending is presented in this paper. A total of 17 experiments was performed with both oriented strand board (OSB) and plasterboard used as the sheathing material and with varying connector spacing employed between the sheathing and the steel members. Material tests and geometric imperfection measurements were also undertaken. The tested specimens comprised a single 2.4 m long cold‐formed steel member sheathed on both sides and secured at its ends to top and bottom tracks. Eight pure compression tests with plasterboard and OSB sheathing and with the spacing of the connectors varying between 75 mm and 600 mm were initially performed. Specimens with OSB were then tested under pure bending and also under combined loading, by first applying a compressive load corresponding to the 75%, 50% or 25% of the predetermined axial resistance and then laterally loaded until failure. Reducing the spacing of the connectors from 600 mm to 75 mm resulted in up to 20% and 30% increases in capacity for the studs sheathed with OSB and plasterboard respectively.
Numerical simulation of ultra‐lightweight concrete encased cold‐formed steel structures
Authors: Eid Nathalie , Joó Attila László 
Published: September 2021

AbstractThe use of thin‐walled structures has been increasingly spread in the last few decades due to their big advantages in both structural design and construction methods. Therefore, the recent researches have discussed a wide range of thin‐walled structures applications. However, the resistance of such structures will be decreased by buckling effect; hence, different ways of strengthening methods have been investigated. One of this method is the use of lightweight concrete as a filling of thin‐walled members. Previous experimental research at the Department of Structural Engineering at Budapest University of Technology and Economics, was carried out to investigate the axial behavior of polystyrene aggregate concrete (PAC) braced CFS elements [1]. The effect of PAC has led to increase the load‐bearing capacity and to restrain the global and distortional buckling modes of steel elements. The results revealed that the ultimate load was increased by 37‐94%. A simplified nonlinear finite element model was developed in ANSYS software to be able to predict the peak resistance of PAC filled thin‐walled members. GMNI analyses were carried out to validate the numerical model by the experimental tests. The concrete was modelled by using springs with adequate stiffness, where a parametric study was conducted to determine the proper imperfection amplitudes of different element lengths. The numerical model showed good agreement with test results.