bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conception and design of high‐performance steel‐concrete composite slabs
Authors: Pereira Miguel , Simões Rui , Craveiro Hélder 
Published: September 2021

AbstractThe main advantages of steel‐concrete composites slabs are the speed of construction, the elimination of conventional shuttering and the reduction of props. This structural system is widely used, mainly in the execution of floors in composite buildings. Usually, the longitudinal shear resistance is commonly provided by the embossments along the steel sheet. This paper presents an innovative reinforcing system that increases the longitudinal shear capacity and consequently the structural performance of composite slabs. The system is constituted by a set of transversal reinforcement crossing the steel sheeting which allows to take more advantage of the high bending resistance of composite slabs and increase their ductility. Two experimental campaigns were carried out: a small‐scale test programme, to study the resistance provided by the reinforcing system, and a full‐scale test programme, to assess the efficacy of the proposed reinforcing system. The present study allowed to conclude that the resistance and the ductility of composite slabs using the proposed reinforcing system are significantly increased. The design methodology based on the partial connection method can be used to predict the resistance of a composite slab incorporating the proposed reinforcing system.
FEM Analysis of Bridges with Encased Continuous Shear Connectors
Authors: Vanova Patricia , Kvocak Vincent , Kozlejova Viktoria , Dubecky Daniel , Kanishchev Ruslan 
Published: September 2021

AbstractComposite steel‐concrete constructions with encased I‐beams were initially used as composite floors. Nowadays, they can be usually seen as short railway bridges with span up to 20m. Their main advantages include simplicity of their construction, their low construction height and their effectiveness. To make them more effective, the steel I‐beams were replaced with perforated steel strips. At Technical University of Košice, Faculty of Civil Engineering, several continuous shear connectors with new design were proposed. In order to prove their effectiveness, numerous experiments – push‐out tests, four point flexural tests – were performed at Laboratory of Excellent Research. The purpose was to determine the shear and bending resistance of the connectors. Afterwards, the finite element models were created and analyzed using ABAQUS/CAE software. This paper deals with numerical program of four‐point flexural tests of two strips. The most clue modules ‐ properties, load, step, interaction and mesh are described.
Macro‐modelling of 3D tubular column‐to‐truss beam joints
Authors: NGUYEN Tien Minh , RODIER Anthony 
Published: September 2021

AbstractThe European Research Project “Innovative 3D joints for robust and economic hybrid tubular construction” aims at developing innovative plug‐and‐play joints for hybrid tubular construction where square (or rectangular) tubular columns are combined with truss‐beams composed of cold‐formed lightweight steel beams. This kind of joints provides a highly efficient structural system for modular solutions that are essential for fast‐track construction. An important task of this project is to develop a 3D joint model that takes into account 3D behavior of joints. The 1D component method presented in the Eurocode 3 part 1‐8 is extended to a 3D level by considering all relevant components and interactions between them.In the literature, some studies showed that the out‐of‐plane deformation of the tubular column faces depends on the loading and boundary conditions of the other faces. The first objective of this article is thus to propose a new 2D springs model taking into account the correlation between out‐of‐plane deformations of the faces of rectangular hollow section (RHS) columns. Then, a formulation of a 3D macro‐element of the joint is presented. Finally, the model is validated using two distinct procedures: 1) an analytical procedure implemented in a symbolic calculation software; 2) a modelling by finite elements.
Yield load estimation of plug & play N type RHS truss connections
Authors: Szlendak Jerzy K. , Szpyrka Adrian 
Published: September 2021

AbstractThe article presents a new concept of II generation N type RHS plug & play truss connection, made in non‐welded technology. In II generation of such joints the tension bracing is not made with two flat bars on both sides of RHS chord and connected with a screw passing through the chord (I generation), but with single round rod going through the clamping blocks and threaded at the ends what allows to screw and fix it to the blocks. Representative connections of such truss are analyzed. Concept of resistance calculations of these joints, using the component method, is shown. Test results and the theoretical resistance follows the different modes of the connections failure are compared.
Numerical analysis of the influence of curling on the strength of connections with one bolt
Authors: Toporiš Matej , Može Primož 
Published: September 2021

AbstractCurling failure typically appears in bolted connections with thin plates, where the force is transferred by bolt bearing. The curling phenomena is related to the high compressive stresses caused by bolt bearing, which cause the plates to buckle, reducing the bearing strength of connections. Since the reduction of the bearing strength due to curling is not considered in design codes, the curling phenomenon has been studied numerically to understand the mechanical behaviour and to develop simple design rules that take into account reduction in bearing strength. The reduction factor for reducing the bearing resistance by curling was developed taking into account the Eurocode approach, i.e. by calculating the elastic critical force associated to curling and the relative slenderness. Therefore, the elastic critical force in relation to curling was obtained by parametric buckling analysis in finite element software Abaqus. These results were used to develop a simple analytical model for the calculation of the elastic critical curling force. The reduction factor was obtained from the relationship between the results of parametric GMNIA and relative slenderness. The strength of single bolt connections was determined by geometrical and material nonlinear analysis with imperfections (GMNIA) considering various parameters, namely ratio of the bolt diameter to plate thickness, end distance e1, edge distance e2, material grade (S235, S690), shape and amplitude of imperfections and boundary conditions. The accuracy of the reduction factor for bearing strength is checked on the basis of experimental data given in literature.
Innovative 3D joint for steel modular construction
Authors: da Silva Luís Simões , Tankova Trayana , Craveiro Hélder David , Silva Luís Carlos , Simões Rui , Costa Ricardo 
Published: September 2021

AbstractIn recent years, the modular construction has been used in multi‐story and even high‐rise construction. Pre‐fabrication by off‐site manufacture leads to faster construction, improved quality and reduced resources and waste.The research work presented in this paper is carried out in the scope of the European project INNO3DJOINTS and it aims to develop innovative plug‐and‐play joints which enable modularity. The developed modular construction system is hybrid, whereby tubular columns are combined with cold‐formed lightweight steel profiles to provide a highly efficient structural system. The innovative connection is a device that connects the lightweight truss girder with the tubular column. It consists of a socket welded to the column and a T‐plug which is connected to the truss girder with a lap‐joint. Upon assembly, the T‐plug is simply fitted into the socket. Moreover, the newly developed innovative hybrid plug‐and‐play joints are also suitable for other specific situations such as retrofitting of existing buildings.This paper presents the developed structural system and the characterization of the plug‐and‐play joints based on experimental tests.
Critical Comparison of Assessment Codes for Steel Moment Resisting Frames
Authors: Gutiérrez‐Urzúa Fernando , Freddi Fabio , Sarno Luigi Di 
Published: September 2021

AbstractMany existing steel multi‐storey frame buildings worldwide were designed prior to the introduction of modern seismic design provisions or based on outdated hazard maps considering low values of seismic intensity. This often resulted in buildings showing low performances with respect to earthquake loads. Assessment codes, such as the Eurocode 8 Part 3 and the ASCE 41, have been conceived to provide tools to assess the seismic performance of existing structures, to evaluate their adequacy with respect to the current safety standards and the need for seismic retrofit. However, recent research studies have revealed the necessity for a revision of these codes. In particular, for steel moment resisting frames, the current European regulation shares many similarities with older versions of the American codes, but has failed to incorporate changes based on the state‐of‐the‐art knowledge. In addition, the undergoing update of other parts of the Eurocode motivates a full revision of the current standards. This paper compares the assessment procedures of the European and American codes. Two low‐code steel Moment Resisting Frames were considered for case study purposes and the assessment was performed based on three local Engineering Demand Parameters (EDPs), i.e., column's rotation, beam's rotation and panel zone's shear distortion, and the inter‐story drift as global EDP. Incremental Dynamic Analyses were performed for the development of component and system fragility curves. The present work aims to identify some challenges and to provide some preliminary insights for the revision of the Eurocode 8 Part 3.
Study of behaviour of S235‐S460 structural steel elements cut using laser processes
Authors: Zanon Gabriele , Bursi Oreste S. , Bison Paolo , Valli Alberto 
Published: September 2021

AbstractLaser cutting is an appealing solution to promote steel construction for high machining speed and precision. As a thermal process, it alters the material properties in the heat affected zone (HZA) and, consequently, the structural response at high‐cycle fatigue loadings. With these premises and by means of a multidisciplinary research, the work studies the effects on S235‐S460 steel elements. In order to study the thermo‐mechanical effects produced by the laser cutting process, with particular attention to fiber laser, a finite elements (FE) numerical model was developed with ABAQUS. Both numerical model calibration and validation were carried out through experimental results obtained by means of monitored cutting processes and material tests. The agreement observed between numerical and experimental results highlights the importance of the interdisciplinary research in the study of complex non‐linear thermo‐mechanical problems like those involving laser cutting. Main results of this study concern the effects of laser cutting on the residual stress distribution and on the response of steel elements subjected to high‐cycle fatigue loadings.
Fatigue design in penstocks – comparison of the nominal stress and structural stress method for common details
Authors: Ecker Alexander , Unterweger Harald 
Published: September 2021

AbstractPenstocks in hydro power plants have a very long working life. They can have high pressure variations during service life, especially in pumped storage power plants caused by the dynamic pressure. Therefore, the fatigue design can be a dominating factor in the design of penstocks. In this paper, two common used construction details in penstocks are investigated with the nominal stress and the structural hot‐spot stress method for fatigue verification. The investigated construction details are: i) a wall thickness transition of the penstock with a weld along the circumference and ii) a ring stiffener welded to the penstock. The results of the different methods for fatigue verification for these two construction details are compared with each other, with variation of different geometric parameters. Also an analytical solution for the stresses in the hot‐spot for the two construction details, based on the semi‐membrane theory of cylindrical shells, was developed. Based on that stresses, stress concentration factors kHS are calculated and are available for practical applications in form of presented Tables in this paper. With the calculated stresses by the semi‐membrane theory in the hot‐spot it can be shown, that they are nearly equal to the hot‐spot stresses of a Finite‐Element‐Analysis, based on the IIW recommendation. Finally, a recommendation for fatigue verification of the two common details in penstocks is given.
Detection of short cracks in riveted connections using Lock‐In‐Thermography
Authors: Sieber Lars , Urbanek Ralf , Bär Jürgen 
Published: September 2021

AbstractAlthough many riveted bridge structures made of old structural steel from the 19th and early 20th centuries are still in use today, there is usually no need to replace them. When assessing these steel structures with regard to necessary refurbishment or strengthening measures, engineers need information about the remaining fatigue lifetime in particular.Often no sufficient remaining fatigue life can be determined based on normative S‐N‐curve assessment. An initiation of fatigue cracks has to be assumed. These cracks occur primarily at the edge of the rivet holes. In the early phase of crack growth below the rivet head, the crack cannot be found in a visual inspection of the structure. For this reason, the remaining cyclic lifetime based on fracture mechanics is determined assuming a start length of the crack beyond the rivet head.This paper reports investigations using thermoelastic stimulated Lock‐In‐Thermography as a NDT method for detection of hidden cracks in riveted joints. The results have shown that cracks below rivet heads can be detected. This is possible despite the presence of a corrosion protection coating. The detectable crack length depends mainly on the level of stress and the loading frequency.
Fatigue Life Prediction of Welded Girders with Flange Thickness Transitions and Cope Hole
Authors: Röscher Stefanie , Knobloch Markus 
Published: September 2021

AbstractThe paper presents an analytical and numerical approach for the fatigue life prediction using local concepts. A Two‐Stage‐Model is applied to a welded girder with thickness transition and cope hole to determine its fatigue life. The model follows the distinction between crack initiation and crack propagation according to the phenomenological background. Using the Strain‐Life‐Approach and the Crack Propagation Approach the local geometry and likely failure position influence the determined fatigue life for the initiation and propagation phase individually. The results are presented in terms of S‐N curves for initiation, propagation, and total fatigue life.
Numerical‐experimental analysis of a braced steel frame subjected to fire following earthquake
Authors: Covi Patrick , Tondini Nicola , Korzen Manfred , Tsionis Georgios 
Published: September 2021

AbstractMany historical events have shown that, after an earthquake, fire may be triggered by seismic‐induced rupture of gas piping, failure of electrical systems, etc. The current engineering design methods still ignores many aspects of multi‐hazard and in particular fire following earthquake (FFE) analysis. In this respect, the aim of this paper is to study the behaviour of a braced steel frame subjected to seismic‐induced fire. In particular, FFE numerical analyses were conducted on a four‐storey three‐bay braced steel frame with concentric bracings. The results of the numerical analyses served to design the FFE tests performed on unprotected and protected columns belonging to the bracing system. The fire tests after the seismic event were carried out by considering the effects of the surrounding seismically damaged structure. Results of the FFE tests on unprotected columns are reported along with the numerical model calibration.
Dissipative joints under impact loadings
Authors: D'Antimo Marina , Latour Massimo , Demonceau Jean‐François 
Published: September 2021

AbstractUnforeseen and unpredictable exceptional events can lead to abnormal loading distribution in the structures; however, in such situation, structures have to withstand additional loadings to avoid disproportionate damage and progressive collapse. Impact loadings are among the exceptional events that a structure can experience during its lifetime. In order to give a contribution to the research on impulsive loading on structural joints, this work focuses on the behavior of slide hinge joints (SHJ) with a Symmetric Friction Damper (SFD) under drop weight impact tests. Six drop weight impact tests on a double‐sided beam‐to‐column joints were performed and a 3D finite element model was created and validated in ABAQUS/CAE Explicit. The model includes the calibration of material damage, correlating the equivalent plastic strain to the stress triaxiality, damping of the system, calibrated on elastic impact tests using Rayleigh's classical damping and strain rate sensitivity through the Johnson Cook model. Furthermore, a parametric analysis was performed in order to investigate the influence of three parameters on the joint behavior: the impact velocity, the impact mass and the impact energy. The energy is used to estimate the dissipation rate of the joint, which can be considered as a reliable parameter to quantify the joint behavior under drop weight impact.
Investigation of residual stresses on the fire resistance of unrestrained cellular beams
Authors: Oribi Sabrina Benyettou , Kada Abdelhak , Lamri Belkacem , Mesquita Luis MR 
Published: September 2021

AbstractIt is being a common engineering practice to use steel beams with web openings in buildings requiring long spans, besides giving an important additional advantage of allowing services through instead of underneath the beams. The presence of these openings is penalizing the carrying capacity at ambient temperature and in the case of fire due to large cells and double nonlinearity geometric and material a complex behaviour take place. In this study, numerical models for beams having closely spaced large openings are simulated with ISO834 fire loading including both nonlinearities cited above in the primal investigation. Followed as a second investigation, is the effect of residual imperfections added to the numerical model mentioned above and simulated for different diagrams as presented within updated literature. All simulations were done using the finite element software ANSYS, to analyse the results captured for lateral torsional buckling (LTB) behaviour in terms of vertical and lateral displacement, von Mises stresses for different sections at ambient and fire conditions. For this parametric study, the change in cross‐section geometries, opening spacing, beam length on the LTB of cellular beams is analysed.
Post‐fire ductility of reinforcing steel
Authors: Lapuebla‐Ferri Andrés , Pons David , Romero Manuel L. 
Published: September 2021

AbstractIn this work, the post‐fire ductility of steel reinforcements in reinforced concrete structures was studied experimentally. Specimens were subjected simultaneously to a constant tensile load and a heating up to a target temperature, which was a percentage of the ‘critical temperature’ for the load level applied. After that, the specimen was left to cool to room temperature and submitted to tensile testing in order to evaluate its residual ductility. Critical temperatures for each load level tested were obtained by performing transient‐state tests. In addition, unloaded specimens were subjected to the same thermal cycle of heating and cooling for comparison purposes.Results indicated that the residual ductility of a reinforcement depends on the maximum temperature reached and the load level it was bearing during the heating and cooling thermal cycle. It was demonstrated that ductility properties were not always recovered after cooling down, and the current code requirements for the ductility class of a reinforcement bar were not fulfilled. The obtained information can be relevant when deciding on the eventual reinstatement of a reinforced concrete structure in a post‐fire scenario.
Attempts to improve on the V‐hull structural design for air‐blast loading applications
Authors: Langdon Genevieve , Curry Andrew , Shekhar Vinay , Siddiqui Aashir , Murray Christopher , von Klemperer Chris 
Published: September 2021

AbstractMine resistant ambush protected vehicles often use mono‐V structures in the design of their hulls for blast protection purposes. These hulls deflect blast waves laterally in the event of a landmine detonation directly beneath the vehicle. Lower internal angles offer greater deflection capability, reducing the impulse transfer to the vehicles, but at the cost of increased ride height. This paper reports results of attempts to improve on V‐hull structural designs for air‐blast loading applications, where scaled blast tests are performed to evaluate the designs in terms of structural deformation, rupture and impulse transfer characteristics. Structures with double V and W profiles are compared to mono V structures with a 120° internal angle, such that the proposed designs do not increase the ride height. Results showed that the double V‐structures limit the central deformation, but some designs have severe deformation at the interface of the central V plate and the shallow base angle structure. W structures seem to be susceptible to rupture at low charge masses. There is no single answer to improved blast protection of vehicle hulls, as design choices must be driven by the anticipated threat range, the important performance metrics and other operational considerations.
Simplified and advanced design for stainless steel members under concentrated transverse loading
Authors: dos Santos Gabriel , Gardner Leroy 
Published: September 2021

AbstractA comprehensive investigation into the behaviour of structural stainless steel members under concentrated transverse loading is presented in this paper. A total of 34 member tests and over 500 finite element simulations have been performed covering three types of concentrated transverse loading – internal one‐flange, internal two‐flange and end one‐flange loading, three stainless steel grades – austenitic, duplex and ferritic and key influential parameters such as bearing length, web slenderness and beam span. The results have shown that existing design recommendations are conservative and that there is considerable scope for the development of more economical design guidance. New design equations are proposed that offer 10% to 20% improvements in capacity predictions over the current design formulae in EN 1993‐1‐4. These proposed design equations are to be included in the next revision of the European standards. An alternative design approach based on numerically generated reference loads – i.e. the plastic collapse and elastic buckling loads – in conjunction with strength curves, has also been proposed. This advanced FE‐based design approach allows the extension of the design scope to non‐standard cases, such as webs with partial depth stiffeners and members with web holes. The reliability of both design approaches has been successfully verified by statistical analysis.