bluuebunny/crossref_metadata_2025_split huggingface dataset:
05.09: Experiment study on square steel tubular columns: Under compressive axial force with monotonic antisymmetric bending moment
Authors: Aoyama Masahiro , Mitsui Kazuya , Sato Atsushi 
Published: September 2017

ABSTRACTIn Japan, square steel tubular columns are widely used. When the building is subjected to a lateral force, columns will subject axial force with antisymmetric bending moment simultaneously. Therefore, it is important to design the column under these combined loading in the ultimate limit state to guarantee the safety. Recommendation for Limit State Design of Steel Structure (LSD) [1] specifies the requirements for columns to guarantee sufficient strength and ductility. The plastic deformation capacity of the columns that are subjected to the compressive axial force with one end monotonic bending moment are ensured more than 3 by LSD. However, specific deformation capacity of the column that are subjected to the compressive axial force with monotonic antisymmetric bending moment is hardly shown in experimental test. Therefore, it is necessary to gather more data of maximum strength, deformation capacity, and elasto‐plastic behaviour of square steel tubular columns by testing. Moreover, second‐order effects is needed to take into account because high compressive axial force leads to elasto‐plastic instability.In this study, testing where axial force with monotonic antisymmetric bending moment are applied to the columns simultaneously are conducted. Maximum bending moment, deformation capacity, and second‐order effect that will be caused by Pδ moment were evaluated from the test results. Comparison between LSD requirements and test results were also shown.From the test results, followings are found.
1) The plastic deformation capacity of the square steel tubular column will be determined by either local buckling or Pδ moment.
2) When second‐order effects determined the plastic deformation capacity, the plastic deformation capacity R of the columns had a linear relation between N/Ny.λc02. When the value of N/Ny.λc02 is smaller than 0.25, a plastic hinge was formed at the end of the column, and the plastic hinge determined the collapse mechanism.
3) The current LSD limitation provided conservative results, and the plastic deformation capacity greater than 3 was observed even if the limitation was not satisfied.
05.14: Lateral torsional buckling of steel beams: Effect of discrete flexible intermediate supports at the upper flange
Authors: Unterweger Harald , Kettler Markus , Loschan Sarah 
Published: September 2017

ABSTRACTTo avoid lateral torsional buckling in steel constructions, beams are often stiffened with discrete flexible intermediate supports (e.g. purlins in roof structures with bracings), which reduce lateral deformations of the flanges out of plane. Very often, these intermediate lateral supports can't be assumed as fully rigid and only restrain one of the flanges (i.e. no torsional restraint available), leading to a design situation that is only insufficiently reflected in EN 1993‐1‐1. Neither commonly used interaction formulae, derived on the basis of free single span members with fork end conditions and for members supported laterally and torsionally by intermediate rigid restraints, nor the simplified assessment method for beams with restraints in buildings (clause 6.3.2.4), based on a lateral buckling check of the compression flange, lead to an appropriate solution.In this paper, the results of an extensive numerical parametric study on beams with intermediate flexible lateral supports at the upper flange are presented.In the first part of the paper the focus is on the appropriate selection of the relevant buckling mode for the geometric imperfections, to obtain the minimum load carrying capacity within a numerical nonlinear calculation. As expected, a decrease of the spring stiffness always leads to a reduced elastic critical buckling load. Nevertheless, when assuming geometric imperfections based on the 1st buckling mode, this may lead to a higher ultimate load than for the system with rigid intermediate supports, when identical imperfection amplitudes are used.In the second part of the paper a first design proposal is presented, valid for different moment distributions and number and stiffness of intermediate supports.
05.15: Development of circular tube slenderness classifications under axial and bending actions
Authors: Rotter John Michael , Sadowski Adam Jan 
Published: September 2017

ABSTRACTLocal buckling in circular tubes differs from that in cross‐sections formed from flat plate elements (I, H, RHS etc.) because the latter retain their original shape up to the point of local buckling and plates are not very sensitive to minor geometric imperfections. By contrast, the curved form of the circular tube or cylindrical shell is very sensitive to minor imperfections and under bending is also strongly affected by geometric nonlinearity when the tube is significantly long. The classification of circular hollow tubular sections (CHS) into Classes 2, 3 and 4 is thus more complicated than for flat plate sections. It may be also noted that the “effective section” treatment of flat plates in Class 4 cannot be used for cylindrical shells. These differences, often ignored, have led to a very wide discrepancy in the classification rules for tubes in different international standards.This paper sets out a clear description of the factors behind the development of new classification rules for CHS designed for adoption into EN 1993‐1‐1 [1]. The effects of length, full and partial plasticity, imperfections and cross‐section distortion are all included using individual provisions. It is also believed that these are the first rules to attempt a rigorous treatment of the resistance of Class 3 CHS subject to both bending and axial compression. The fully plastic resistance of tubes under axial force and bending is also treated with great precision. The formulation is novel, so may prove interesting to others who seek to develop similar rules for other structural shapes.
05.28: Deformation capacity of steel column under combined loading: Compressive axial force with double curvature bending moment
Authors: Sato Atsushi , Ono Tetsuro 
Published: September 2017

ABSTRACTHorizontal forces subjected to the moment resisting frame will be essentially resisted by the flexural manner of the columns. Horizontal forces are significant under seismic action; combined loading condition have a possibility to destabilize the columns. In ultimate limit state design, formation of the plastic hinge at the columns are allowed; however, it not permitted to lose its resistance. Moreover, sufficient deformation capacity at the plastic hinge should be guaranteed to fulfill the collapse mechanism of the structure. Following failure modes can occur in the column; 1) local buckling, 2) lateral torsional buckling for the open section subjected to strong axis bending, and 3) in‐plane second‐order effect instability. These failure modes should be prevented to guarantee the ductility of the plastic hinge which is formed in the column.In this paper, column instability due to second‐order effect introduced by compressive axial force is studied. Numerical simulation is used to clarify this issue and in‐plane behaviour is evaluated. Parameters selected for the analysis are cross‐section shape, slenderness ratio, compressive axial force, bending moment distribution, material strength, and initial imperfection. From the results, it was found that material strength is not a significant parameter for column instability which is caused by the second‐order effect. Finally, the formula which can guarantee a sufficient deformation capacity to the column was proposed. Proposed formula was composed by the information of cross‐section shape, slenderness ratio, bending moment distribution, and force level subjected to the column.
05.31: Experiments and fem‐simulations of local buckling of sand‐filled tubular piles
Authors: Winkel Jort , Kostis Nikolaos , Peters Dirk Jan , van Es Sjors Harry Jan 
Published: September 2017

ABSTRACTThin‐walled large‐diameter tubular piles loaded in bending are susceptible to local buckling. Depending on the bending moment distribution over the length of the pile, this local buckling failure may occur in the part of the pile that is embedded in the soil. In large‐diameter piles, soil is also present at the inside of the pile. The soil mass inside and outside of the pile may influence the bending behaviour and local buckling behaviour of the piles.In case the internal soil plug consists of granular material and is sufficiently stiff and resistant, the soil influences the buckling shape and the critical stress and strain at which local buckling occurs.Experiments that were performed in 2012 on empty and fully sand‐filled tubes loaded in pure bending showed a significant effect of the sand‐fill. The experiments were verified with finite element analyses to better understand the occurring failure mechanisms in tube and soil and the effects of parameter variations.In 2014, new experiments were carried out in the port of Rotterdam on 914 mm diameter piles installed in the harbour bed. After installation, the embedded part the piles remained predominantly filled with soil, whereas the upper part was empty. Eight piles were installed and were loaded with a lateral force up to excessive yielding and local buckling failure. These experiments were analysed with FEM calculations. These analyses included effects of the soil plug and the soil around the pile.The outcomes of the FEM model calculations confirm the experimental findings of a change in buckling shape as a result of the presence of sand inside the pile. The experiments and finite element analyses show that there is an evident contribution of the inside sand with certain properties to the resistance to local buckling. For the piles that are not completely filled with sand but have a plug at a certain level, design rules for the effect of the sand plug were derived.
05.33: LTB resistance of rolled I‐section beams: FEM verification of Eurocode's buckling curve formulation
Authors: Giżejowski Marian Antoni , Szczerba Radosław Bronisław , Gajewski Marcin Daniel 
Published: September 2017

ABSTRACTThis paper attempts to verify the Eurocode's buckling resistance criteria in case of rolled I‐ and H‐sections in monoaxial bending about their major axis using finite element simulations and two imperfection modelling techniques, namely a) using the equivalent geometric imperfection concept in which the effect of material and geometrical imperfections is represented by an equivalent minor axis bow amplitude and the lowest eigenmode imperfection profile, and b) the separate inclusion of material and geometrical imperfections. In the latter approach, material imperfections are based on the standard rolled residual stress patterns consisting of compression/tension peak values dependent upon the h/b ratio. Moreover, the geometric imperfections are included as the tolerance limit of steel I‐section rolled products. Common and higher grades of steel products are considered. The finite element shell model is utilized and built within the ABAQUS software. The Eurocode's resistance criteria are verified by using the results of FEM simulations. An impact of the moment gradient on the member buckling resistance as well as the plateau limit evaluation and the resistance increase as a result of large twist rotations accounted for are assessed. Remarks in relation to analytical formulations presented in Eurocode 3 are drawn.
05.34: Influence of temporary bridge decks on continuously welded rails
Authors: De Backer Hans , Mys Jan , Van Puymbroeck Evy 
Published: September 2017

ABSTRACTThe possibility of omitting rail expansion devices from the track configuration, when continuously welded rail is continued over temporary bridge decks, is investigated in detail. More specifically, the related rail track to temporary bridge interaction phenomena are analysed using finite element modelling. A parametric analysis assesses the additional rail stresses due to moving trainloads and temperature variations, based on stipulations provided in the unit identification code 774‐3R. In addition, the model is expanded to a more complex structure that is able to simulate the buckling behaviour of the rail track using non‐linear methods. It can be concluded that, depending on the magnitude of two main factors, the lateral ballast resistance and the amplitude of the initial track misalignment, a considerable reduction of the track stability might arise.
05.37: On stability of unbraced steel frames with semi‐rigid joints
Authors: Krystosik Przemysław 
Published: September 2017

ABSTRACTThe paper presents the issue of unbraced and semi‐rigid steel frames stability with special attention paid to the problem of determining buckling length Lcr of columns in these frames.The paper discusses ways of buckling length determination in frames columns with the use of selected, simplified procedure, as well as numerical method of stability analysis. The presented procedures and the analysis methods were used in calculations of certain steel frames. On the basis of presented results, it has been shown that in many practical cases, the simplified procedure of buckling length determination can give error‐prone results.The issues presented in the paper are important from the practical point of view, and therefore, they should be taken into account in the design process of such frames.
05.38: Design procedure development of light gauge built‐up beam to ensuer yield bending strength: Antisymmetric bending moment
Authors: Yoshimoto Shun , Sato Atsushi 
Published: September 2017

ABSTRACTAmerican Iron and Steel Institute (AISI) stipulates a lateral force resisting system called CFS‐SBMF. In this system, built‐up beams are connected to hollow section columns by bolts to compose moment frame.Structural system proposed in previous study used built‐up beam in shape of rectangular section. Built‐up beams are composed by double channels toe‐to‐toe. When the beam is subjected to loads, 4 pattern of collapse mechanisms can be expected.
1) Yielding;
2) Lateral torsional buckling (LTB) of built‐up member;
3) LTB of individual channel between the connecting plates;
4) LTB of individual channel due to lack of the connecting plates stiffness and strength.
Yielding, full capacity of the member, is expected in seismic design to maximize the performance of the structural system; therefore, it is necessary to prevent collapse mechanisms from No.2 to No.4.To prevent the collapse mechanism No.2, following shall be fulfilled. Assuming that the section of the beam is rectangular steel tubular member. Then the length of the beam will be checked with this length; it is fulfilled when the beam is shorter or equal to the computed allowable length.To prevent the collapse mechanism No.3, following numerical simulation shall be conducted to propose design procedure. Length between connecting plates is set as parameter; connecting location was distributed equally in the longitudinal direction of built‐up member.To prevent the collapse mechanism No.4, following design procedure is proposed. It was assumed that failure at the connecting plate, i.e., yielding, will not occur when it is designed to be stronger than the connected channel flange out‐of‐plane strength.Finally, design procedure that can prevent unexpected collapse modes was verified by numerical simulation. Proposed design procedure is applicable to design appropriate built‐up beam in an economical manner.
05.41: A unified catastrophe theory approach for the in‐plane buckling of steel arches under point gravitational loading
Authors: Pantazi Vasiliki S. , Sophianopoulos Dimitrios S. 
Published: September 2017

ABSTRACTThe problem of the buckling response of various types of steel arches has been the subject of a vast number of earlier as well as recent papers and chapters of books. Namely, the majority of all these works aimed – via analytical and/or computational approaches – to establish the nature of the postbuckling response of the foregoing structures. It has been found over the years that two types of loss of in‐plane stability are dominant: (a) snap‐through, a characteristic of shallow (flat) arches (low height to span ratio), in a symmetric or asymmetric mode (limit point or bifurcation), and (b) sideways buckling (deep arches). In the latter situation, the axial inextensibility (being a justified simplifying assumption) becomes dominant and in the case of radial load and circular arch configuration the whole analysis is rather easy and convenient, using equilibrium considerations. On the other hand, low arches (with unavoidable shortening of their center line) can be thought of as curved beams; hence their buckling analysis may be performed from the viewpoint of energy. However, there not seems to be a unified approach overall, especially since the geometry of arches may be significantly varying, from circular to elliptical, parabolic, sinusoidal and catenary, and hence the height at the crown and the span are not the only parameters this geometry is dependent on. Moreover, if one considers a point gravitational loading acting on the arch, a case scarcely reported, then the whole analysis is multiparametric, since it involves (a) the value of the load and its position, (b) the cross‐sectional and material characteristics and (c) the geometrical configuration parameters. This work aims to provide a unified approach for the foregoing problem based on the Theory of Catastrophes. The total potential energy function involving all the parameters is firstly established, and furthermore all restrictions related to boundary conditions, geometry, material and cross‐sectional properties. Using an approximate 4th order polynomial postbuckling shape, it was found that the problem at hand is governed by a singularity that strongly resembles the butterfly. The work is ongoing and will hopefully reveal interesting future results for structural design purposes.
05.43: Lateral‐torsional buckling of beams of double symmetrical and mono‐symmetrical cross‐sections loaded perpendicularly to the axis of symmetry: Experimental verification
Authors: Horáček Martin , Melcher Jindřich 
Published: September 2017

ABSTRACTThe current design procedures listed in the European standards provide general rules for the calculation of the effects of lateral torsional buckling of steel members. The buckling resistance of the ideal beam (without any imperfections) is represented by the elastic critical moment, which is used for the determination of the relative slenderness. In the general document of Eurocode 3 are no analytical solutions for the calculation of the elastic critical moments. The Czech and Slovak National Annex of EN 1993‐1‐1 provide the procedures for the elastic critical moment calculation for at least mono‐symmetrical profiles loaded in the plane perpendicular to the axis of symmetry. There are no comments in the national annexes of the other European Countries related to the determination of elastic critical moment by analytical way.This paper focuses on the experimental verification performed in the laboratory conditions in order to prove the save and efficient design of bended beams with respect to lateral torsional buckling based on the procedures listed in the Czech or Slovak National Annex. Freely supported beams are loaded in the 1/3 of the beam with 2 point loads. The special attention is given to the method of loading, which allows free lateral torsional buckling of the beam without any restraints to the horizontal displacement and rotation of the beam. In order to examine the pure effects of lateral torsional buckling the effects of local instabilities such as for example local buckling or web crushing under the concentrated load, the test specimens are supplemented by suitably located stiffeners.
07.03: Distortional‐global interaction in lipped channel beams: Part II: Strength, relevance and DSM design
Authors: Martins André Dias , Camotim Dinar , Dinis Pedro Borges 
Published: September 2017

ABSTRACTThis work aims at presenting and discussing numerical results concerning the post‐buckling behaviour, strength and design of two types of simply supported lipped channel (LC) beams under uniform major‐axis bending and undergoing distortional‐global (D‐G) interaction. The relevance of the interaction effects is assessed by determining the beams whose ultimate strength and/or failure mode are visibly affected by them. Distinct (i) global‐to‐distortional critical buckling moment ratios (RGD) and (ii) yield‐to‐non critical buckling (distortional or global) moment ratios (Ry) are considered and, thus, different failure mode natures (global, distortional or interactive) are expected. For each beam type, combinations of 41 geometries and 11 yield stresses are dealt with, in order to (i) characterise the beams experiencing “true D‐G interaction” (RGD≈1.0) and “secondary global‐bifurcation D‐G interaction” (RGD >1.0 + high Ry) and (ii) investigate the possible occurrence of “secondary distortional‐bifurcation D‐G interaction” (RGD <1.0 + high Ry). The results presented consist of (i) relevant non‐linear equilibrium paths, (ii) deformed configuration evolutions along those paths and (iii) figures providing the failure mode characterisation. Then, the numerical failure moments obtained are compared with their predictions by (i) the currently codified DSM (Direct Strength Method) beam global and distortional strength curves, and (ii) proposed DSM‐based design approaches, specifically developed to handle D‐G interactive failures.
07.09: Trapezoidal sheet hangers and concentrated or linear load distribution in profiled sheeting
Authors: Šorf Marek , Jandera Michal 
Published: September 2017

ABSTRACTWith increasing depth and load‐bearing capacity of cold‐formed trapezoidal sheeting, they are used more often with hangers bolted to the webs of the sheeting. Several tests of the hangers resistance are shown for various type profile, sheet thickness and possible perforation of the web which are the main variable factors affecting the load capacity of the hanger connections. A simple and safe design procedure is given. More importantly, the distribution of the load applied by the hangers to the profiled sheeting ribs as concentrated load per the rib is often critical for the profile resistance in bending or to satisfy the deflection limit however the distribution of the load between the ribs is not known. Therefore an advanced numerical study (GMNIA) in software Abaqus was carried out for several section types and loading conditions. The model used for the analytical study was again validated by tests. The main conclusion of the paper is a developed design procedure allowing the possible redistribution of concentrated load between the ribs in case of simply supported members whose design is governed by deflection or bending resistance.