bluuebunny/crossref_metadata_2025_split huggingface dataset:
12.02: High strength steel I‐section arches: Inelastic lateral buckling and moment capacity
Authors: Pi Yong‐Lin , Bradford Mark Andrew , Liu Airong 
Published: September 2017

ABSTRACTLittle research has been reported about high strength steel (HSS) arches and no adequate code provisions are available for their strength design although HSS structures are increasingly used in engineering construction. This paper presents an investigation of global inelastic lateral‐torsional buckling and strength of HSS I‐section arches using a validated finite element model. HSS arches in uniform bending are considered and the yield strength of the HSS used in the investigation is 460MPa, 690MPa, and 960MPa. Initial out‐of‐plane bow and twist imperfections and residual stresses are included in the investigation. It is demonstrated that the HSS influences inelastic lateral‐torsional buckling and strength of HSS arches significantly. The high yield strength of the HSS increases the moment capacity of HSS arches and reduces the difference between their inelastic and elastic lateral‐torsional buckling moments. Formulas for the dimensionless capacity of HSS arches in uniform bending, which is consistent with those in AS4100‐1998 and in Eurocode 3 for mild steel members, are developed. It is shown that the predictions of the new formulas for the dimensionless moment capacities of HSS arches in uniform bending agree with the finite element results very well.
12.08: Cross‐section stability of stainless steel channel sections subjected to combined loading
Authors: Liang Yating , Zhao Ou , Long Yue‐ling , Gardner Leroy 
Published: September 2017

ABSTRACTThis paper presents a comprehensive experimental and numerical study of the cross‐section stability of stainless steel channel sections under combined axial compressive load and major axis bending moment. The experimental investigation included material coupon tests, initial geometric imperfection measurements and eight eccentrically loaded stub column (combined loading) tests, while the numerical modelling programme comprised a valiadtion study and a parametric study to generate further structural performance data. Both the experimental and numerical results were carefully analysed and then used to assess the accuracy of the current Eurocode design provisions for stainless steel channel sections subjected to combined loading. Generally, the Eurocode was found to result in unduly conservative and scattered strength predictions. Improved design rules have been proposed through extension of the deformation‐based continuous strength method (CSM) to the case of channel sections under combined loading. Comparisons between the proposal and the test and numerical results indicate a high level of design accuracy and consistency in the predictions. The reliability of the new proposal has also been confirmed by means of statistical analyses according to EN 1990.
12.13: On recent characterisations of the post‐yield properties of structural carbon steels
Authors: Sadowski Adam J. , Rotter J. Michael , Ummenhofer Thomas 
Published: September 2017

ABSTRACTNew design methodologies are being developed that permit the full plastic condition and strain hardening properties of steel members and structures to be exploited. However, it has long been recognised that even the full plastic moment of a cross‐section cannot be attained assuming only an ideal elastic‐plastic material law, since infinite curvatures would be required to do so. Further, tests on structural members routinely show that, due to strain hardening, the full plastic condition is exceeded at finite slendernesses where one might expect stability to affect the result. This indicates that strain hardening should be a key consideration in design. Unfortunately, the strain hardening properties of carbon steels are not guaranteed by any standard or steel manufacturer, and no reliable depository of information is known to exist. Similarly, the proliferation of powerful modern finite element software that can handle significant geometric and material complexities is at odds with the paucity of information available to the analyst on the reliable choice of post‐yield material properties for carbon steels.This paper presents a brief overview of the results presented in recent publications by the authors that attempt to tackle this problem. The intention is to alert the structural engineering community to the wealth of information contained in a typical tensile stress‐strain curve relationship beyond that which is commonly reported, and to show the tentative progress that has been made in characterising the post‐yield properties of some of the most common structural steels. A specialised algebraic formulation is used to process a database of 225 stress‐strain curves of various grades, allowing an accurate assessment of their post‐yield material properties. These include the length and gradient of the yield plateau, the initial tangent strain hardening modulus of the post‐plateau region, and preliminary statistical bounds for these for the most common grades. The paper additionally flags the novel notion that the yield plateau itself exhibits a small but finite and statistically significant positive gradient, which is potentially important in structural resistance calculations.
12.14: Ultimate response and design of stainless steel continuous beams
Authors: Kokosis Georgios , Gkantou Michaela , Theofanous Marios , Dirar Samir 
Published: September 2017

ABSTRACTDue to lack of available experimental data, plastic design of stainless steel (SS) indeterminate structures is currently not permitted by Eurocode 3: Part 1.4, despite the excellent material ductility and the existence of a Class 1 slenderness limit, thereby compromising design efficiency. The high initial material cost warrants the development of novel design procedures, in line with the observed structural response, which fully utilise its merits, improve cost‐effectiveness and minimise material consumption. This paper focuses on the response and design of stainless steel continuous beams. FE models of austenitic and lean duplex stainless steel SHS and RHS were developed and validated against published test data. The validated FE models were used to conduct parametric studies, in order to obtain structural performance data over a range of cross‐sectional slendernesses, cross section aspect ratios, moment gradients and loading arrangements. Based on obtained results, it was concluded that the current Eurocode 3: Part 1.4 approach significantly underestimates the strength of continuous beams. This is because the formation of successive plastic hinges and moment redistribution in indeterminate structures with adequate deformation capacity, as well as the effect of strain‐hardening at cross‐sectional level, are not accounted for. It is shown that accounting for both strain‐hardening and moment redistribution is of paramount importance for design. To this end, the application of the Continuous Strength Method (CSM), which rationally accounts for local buckling at cross‐section level, is extended to the design of stainless steel indeterminate structures. Further research is underway to quantify the effect of high shear stresses on the design procedure and to extend the method to the design of pinned based and fixed based stainless steel frames.
12.15: Structural performance of stainless lap bolted joints
Authors: Freire Raphael , da Silva Vellasco Pedro Colmar Gonçalves , da Silva André Tenchini , de Lima Luciano Rodrigues Ornelas 
Published: September 2017

ABSTRACTThe stainless steel employed in the structural elements present high corrosion resistance, durability, fire resistance and high aesthetic value compared to those constructed using carbon steel. In contrast, the stainless steel structures design is made following the requirements based on the carbon steel analogies. In fact, the structural performance of stainless steel is complex and dissimilar where some stainless grades presenting nonlinear tension versus strain curves without a defined yield plateau and large strain hardening. These properties influence on structural performance of the lap bolted joints. The Eurocode 3 pt. 1.4, one of the most adopted design codes, recommends two structural design criteria for the stainless steel elements under tension: ultimate resistance of the net cross‐section at holes or plastic resistance of the gross cross‐section. The present work aimed to investigate the structural response of lap bolted joints made of three stainless steel grades: austenitic, ferritic and duplex. Nonlinear numerical analyses has been carried out using ABAQUS 6.14 program where the response have shown a good agreement in terms of the maximum loads and failure modes when compared to the performed experiments. The results indicated a conservative level of safety from Eurocode 3 pt. 1.4 code provisions in comparison to the experimental results.
12.17: Economical design of high strength steel trusses using multi‐criteria optimization
Authors: Mela Kristo , Tiainen Teemu , Heinisuo Markku 
Published: September 2017

ABSTRACTEvaluating the economy of high strength steel in structural applications is typically difficult since accurate cost data is not available. In this study, multi‐criteria optimization approach is employed to provide the designer with a decision‐making tool for finding compromise solutions between material and fabrication costs without the need for cost data. Structural weight, painted area and volume of welds are the three conflicting and non‐commensurable criteria considered. These quantities represent the main sources of costs in tubular trusses, namely material, surface treatment and welding. By examining the Pareto optimal solutions, the trade‐off between weight savings and fabrication costs can be assessed. The proposed approach is especially suitable when applying topology optimization, as the number of braces can be varied during optimization, which has clear impact on the fabrication costs.
12.20: Mechanical properties of cold‐formed stainless steel
Authors: Mařík Jan , Jandera Michal 
Published: September 2017

ABSTRACTStainless steel is a material of many specific properties, which significantly differs from carbon steel ones. One of the main attributes of all stainless steel grades that haven't been satisfactorily investigated is the significant change of stress‐strain behaviour due to cold‐forming in fabrication process of structural elements. In the last decades some proposals for the most basic material properties have been developed. However they don't predict the whole stress strain diagram. In the paper presented research involves testing programme focused on virgin and cold‐worked elements of four stainless steel grades: austenitic (1.4404), ferritic (1.4003), duplex (1.4462) and lean duplex (1.4162). Selected grades represent the most used families of stainless steel specified for structural purposes and used for section fabricating via cold‐forming. Gathered data together with other available experimental results serve as a base for analytical part of the research. The main output was establishment of an analytical solution for a stress‐strain diagram of a whole structural cross‐section represented by square and rectangular hollow sections. Further objective was to establish relationships for mechanical properties such as ductility or ultimate strength as these issues have not been sufficiently investigated before. Conclusions contribute to the common design of stainless steel structures and help to precise finite element analyses using enhanced properties of cold‐worked stainless steel.
12.23: Research on low‐yield‐point steels in Tsinghua University
Authors: Shi Gang , Wang Xun , Zhang Yong 
Published: September 2017

ABSTRACTFor the advantages of low yield strength, high tensile‐to‐yield strength ratio and excellent ductility, low‐yield‐point steels are extremely applicable for energy dissipation in seismic design of steel structures, so they are more and more used in steel structures in seismic areas. To get comprehensive understanding on material properties of low‐yield‐point steels and give support to the design and engineering application, the research group in Tsinghua University has conducted the study on the LY100, LY160 and LY255 three grades of low‐yield‐point steels in China. The data of mechanical properties such as tensile strength, yield strength, percentage elongation and impact work from the steel manufacturer have been collected and analyzed by the mathematical statistics method based on the reliability theory, and the partial factors for resistance of low‐yield‐point steels have been proposed. Also low‐yield‐point steel coupon specimens were tested by different cyclic loading programs, and the constitutive models under cyclic loading were proposed and calibrated. Furthermore, the low‐cycle fatigue behavior of low‐yield‐point steels were studied by tests, and the test results can be used to predict the cyclic loading safety and life of low‐yield‐point steel components in steel structures under earthquakes.
13.01: Net cross‐section failure of steel plates at bolt holes: Numerical work and statistical assessment of design rules
Authors: Snijder H.H. , Dekker R.W.A. , Teeuwen P.A. 
Published: September 2017

ABSTRACTThis paper concentrates on the design rule for net cross‐section resistance as one of the design rules relevant for bolted connections. In a previous paper twelve experimental test results were presented of a test program containing 28 specimens in total, with different bolt hole configurations, ranging from one bolt hole to multiple staggered and non‐staggered holes. The specimens contain bolts or not, meaning that plates with only bolt holes are tested as well as plates connected by bolts. This paper now summarizes all experimental test results.Subsequently, these experimental test results were used to validate a finite element model. Strain hardening needs to be taken into account in the numerical model. The paper discusses the result for different strain hardening models available in codes.The validated finite element model was then used to create a database of numerical test results. In the database, configurations of plates with and without bolts are included. Bolts M16, M20 and M24 are considered. Both staggered and non‐staggered bolt configurations are included with different end and edge distances and pitches. Plate thicknesses range from 8 to 26 mm. Most configurations use steel grade S235 but S460 was also considered.The database was used to perform a statistical assessment of the current design rule for net‐section resistance, using the procedure of Annex D of EN 1990 as further developed in the RFCS project Safebrictile together with the statistical distributions for steel properties of Safebrictile.It was found that the current partial factor is over‐conservative and can be substantially lowered. Alternatively, the design rule can be modified. The paper concludes with a proposal for a new design rule.
13.03: Bending‐shear interaction of steel I‐shaped cross‐sections: Statistical investigation
Authors: Dekker R.W.A. (Rianne) , Snijder H.H. (Bert) , Maljaars J. (Johan) 
Published: September 2017

ABSTRACTClause 6.2 of EN 1993‐1‐1 covers the cross‐sectional resistance of steel sections. The bending‐shear interaction design rules for I‐shaped cross‐sections make use of a reduced yield stress for the web area. On this basis, a reduced design plastic resistance moment allowing for the shear force is presented. The effect of shear on the bending resistance may be neglected if the shear force is less than half of the plastic shear resistance of the cross‐section. Plasticity in the Eurocode is described by the well‐known Von‐Mises yield criterion, however, the formula used for the reduced yield stress deviates from this criterion, resulting in sometimes greater and sometimes smaller values. The background of the Eurocode formula for reduced yield stress can be found in a publication by Drucker. The purpose of the present research is to investigate the influence of shear on the bending resistance of I‐shaped steel cross‐sections with as result a possible reconsideration of the Eurocode design rules.At Eindhoven University of Technology an experimental investigation on bending‐shear interaction in rolled steel I‐shaped sections was performed. A numerical model was developed in Abaqus Finite Element software to simulate the experiments. With the validated numerical model a larger database of numerical ‘test’ results was generated, which was subsequently used in a statistical analysis following Annex D of EN 1990 as further developed in the RFCS project Safebrictile. The statistical distributions of the steel properties recommended by Safebrictile were adopted.This paper presents the results of the statistical analysis and safety assessment of the strong axis bending‐shear interaction design rule currently present in Eurocode 3. The parametric test group consists of HEA, HEM and IPE sections in the steel grades S235, S355 and S460: in total 180 numerical simulations with increasing amount of shear. A stress‐strain model including strain hardening was used in the numerical simulations, since the influence of strain hardening is also largely present in the experimental test program. Based on strain hardening material behavior it is show in this paper that the current partial factor is un‐conservative for shear dominated beams and should be increased. Alternatively, the design rule should be modified.
13.06: Calibration of Eurocode design models of thin‐walled cylinder under bending with full scale tests
Authors: Peters Dirk Jan , Sadowski Adam , Rotter J. Michael , Taras Andreas 
Published: September 2017

ABSTRACTDesign formulas for thin‐walled cylinders in bending show remarkable differences in various codes, including versions of the Eurocodes. Thin‐walled, high grade steel cylinders are used in piles, e.g. in combined walls for quay wall construction or in large mono‐piles for mooring structures or offshore foundations. These piles experience a dominant loading in bending, and may be designed with Eurocode formulas for shell buckling of prismatic cylinders.In recent years, a relatively large number of new results of full scale experiments has become available. These results can be combined with test results from the literature and can be used for calibration of the design model formulas for thin‐walled tubes, in particular in the range that has a high susceptibility to elastic or plastic local buckling. The diameter range of the tests is 400 to 900 mm. The d/t ratios range from 40 to 110 and the steel grades from S235 to S460.New capacity‐based formulas for Reference Resistance Design (RRD) of cylinders in bending have been developed from extensive GMNIA calculations (geometrically and materially nonlinear analyses with imperfections included) that included many variations of the relevant parameters and buckling pre‐conditions. A calibration against the tests forms a potentially valuable confirmation of those design rules. The methodology of the calibration is based on statistical procedures that prove sufficient reliability according to the Eurocode requirements.Similar to other calibration exercises, it appears that the difference between the nominal and real material strength is, amongst other aspects, an important input parameter for the calibration result.The evaluation performed here shows that the published Eurocode EN 1993–1–6 2007 strength‐based formulas produce conservative results and that the new RRD amendment which produces less‐conservative design values can still be safe.
00.03: European research on steel structures in seismic areas
Authors: Mazzolani Federico M. 
Published: September 2017

ABSTRACTIn Europe the research activities on steel structures in seismic areas is very intense and productive since the ‘80s of the last century. Many research projects have been developed. In particular, the activity started within the Technical Committee 13 (seismic design) of ECCS deeply contributed to the scientific debate and to the genesis of current Eurocode 8, which is currently under maintenance. This paper summarizes the main topics already consolidated and the related research activities currently ongoing, together with the ones needing further developments, in order to highlight the research perspectives of the European community of experts working on the field of steel structures in seismic areas. In particular, the discussion focuses on material properties, local ductility, full strength and dissipative joints, innovative types of links in eccentrically braced frames, capacity design rules, cold‐formed applications, new structural types and devices, the use of steel in structural consolidation.
13.07: Extension of EN 1993‐1‐10 and EN 1993‐1‐12: To higher strengths and thinner sections
Authors: Wallin Kim , Karjalainen‐Roikonen Päivi , Suikkanen Pasi 
Published: September 2017

ABSTRACTThe Eurocode 3 sections EN 1993‐1‐10 and EN 1993‐1‐12 contain tables for the maximum permissible values of element thickness as a function of steel grade, quality and reference temperature. The tables cover steel strengths from S235 to S700 and section thicknesses above 10 mm. The tables have been constructed based on a fracture mechanical brittle fracture analysis using a Charpy‐V impact energy criterion as reference.Ultra high strength steels above 700 MPa are not covered by the tables. Such steels are generally used in thinner sections than 10 mm, when the tables in EN 1993‐1‐10 and EN 1993‐1‐12 are limited to section thicknesses above 10 mm. Here, the same basic procedure as used for the tables in EN 1993‐1‐10 and EN 1993‐1‐12 is used to extend them to higher strength steels and thinner sections. The procedure is modified slightly to account for special characteristics of ultra high strength steels and thin sections. These modifications do not affect the present tables, but they provide a smooth transition to higher strength steels and thinner sections. The strong inherent conservatism in the EN 1993‐1‐10 procedure is not affected either.
13.09: Yield stress independent column buckling curves
Authors: Stan Tudor‐Cristian , Jönsson Jeppe 
Published: September 2017

ABSTRACTUsing GMNIA and shell finite element modelling of steel columns it is ascertained that the buckling curves for given imperfections and residual stresses are not only dependent on the relative slenderness ratio and the cross section shape but also on the magnitude of the yield stress. The influence of the yield stress is to some inadequate degree taken into account in the Eurocode by specifying that steel grades of S460 and higher all belong to a common set of “raised” buckling curves. This is not satisfying as it can be shown theoretically that the current Eurocode formulation misses an epsilon factor in the definition of the normalised imperfection magnitudes. By introducing this factor it seems that the GMNIA analysis and knowledge of the independency of residual stress levels on the yield stress can be brought together and give results showing consistency between numerical modelling and a simple modified Ayrton‐Perry formulation. In this paper magnitudes of imperfections and residual stresses in relation to the Eurocode will be discussed. It will be shown that the use of equivalent imperfections may be very conservative if considered by finite element analysis as described in the current Eurocode code. A suggestion is given for a slight modification of the Eurocode formulations of imperfections leading to adequate inclusion of modern high grade steels within the four bucking curves.