In the Eurocode system, for fatigue design of bridges, the recommended partial factor for fatigue... more In the Eurocode system, for fatigue design of bridges, the recommended partial factor for fatigue traffic loads is set to 1. In this paper, the adequacy of this approach is investigated by performing a reliability analysis on two types of welded joint in a main girder of a steel motorway bridge. For this purpose, a weigh in motion measurement dataset belonging to a main Dutch motorway has been compared with the fatigue load model 4 of Eurocode EN 1991-2 with respect to the stress spectrum and the fatigue damage of two structural steel details. Several structural schemes have been considered to study the effect of the shape and length of the influence line. The distributions of the stochastic variables such as dynamic amplification, accuracy of the structural model, and future traffic trends have been estimated or taken from literature. Partial factors for fatigue loads have then been calibrated in such a way that the target reliability is obtained. The influence of each stochastic v...
This paper reports the on-going research into traditional timber frames at the Eindhoven Universi... more This paper reports the on-going research into traditional timber frames at the Eindhoven University of Technology (TU/e) in the Netherlands, see e.g. [1] for a paper presented at WCTE 2014. Traditional timber frames were common structures for centuries. They lost popularity due to high manufacturing costs and low rated perception related to durability and load carrying capacity. Today’s technology provides timber frames and especially connections with high precision at relatively low production costs. This, together with the fact that these structures are still appealing, result in an increasing popularity although, as shown in this paper, the load carrying capacity of the frame regarded as a sway system is (very) low. The realisation of traditional timber frames is still based on craftsmanship without knowledge about strength, stability and stiffness. Traditional portal frames as shown in figure 1 are analysed. The analyses of numerical and experimental results show the peg diamete...
Estimating and reducing uncertainty in fatigue test data analysis is a relevant task in order to ... more Estimating and reducing uncertainty in fatigue test data analysis is a relevant task in order to assess the reliability of a structural connection with respect to fatigue. Several statistical models have been proposed in the literature with the aim of representing the stress range vs. endurance trend of fatigue test data under constant amplitude loading and the scatter in the finite and infinite life regions. In order to estimate the safety level of the connection also the uncertainty related to the amount of information available need to be estimated using the methods provided by the theory of statistic. The Bayesian analysis is employed to reduce the uncertainty due to the often small amount of test data by introducing prior information related to the parameters of the statistical model. In this work, the inference of fatigue test data belonging to cover plated steel beams is presented. The uncertainty is estimated by making use of Bayesian and frequentist methods. The 5% quantile of the fatigue life is estimated by taking into account the uncertainty related to the sample size for both a dataset containing few samples and one containing more data. The S-N curves resulting from the application of the employed methods are compared and the effect of the reduction of uncertainty in the infinite life region is quantified.
An approximate hand method for estimating horizontal deflections in high-rise steel frames with f... more An approximate hand method for estimating horizontal deflections in high-rise steel frames with flexible beamcolumn connections subjected to horizontal loading is presented. The method is developed from the continuous medium theory for coupled walls which is expressed in non-dimensional structural parameters. It accounts for bending deformations in all individual members as well as axial deformations in the vertical members and is more accurate for very tall structures. Additional deformations in the beam-column connections contributing to the overall frame deformations are also included in the analysis. This reduction in the frame stiffness requires the nondimensional structural parameters to be modified. A closed solution of the differential equation for the cantilevered structure yields a rapid assessment of the influence of different types of connection on the overall behaviour. Results for structures that are uniform with height compare closely with results from stiffness matrix analyses.
The use of precast concrete floor slabs in steel framed structures is quite common. In the design... more The use of precast concrete floor slabs in steel framed structures is quite common. In the design of the steel beams, the lateral restraining effect of the precast concrete slab is normally safely neglected. However, the concrete slab will provide some horizontal restraint, even without special provisions such as dowels being present. It may even be that the restraint provided by the floor slab prevents lateral torsional buckling. To investigate the restraining effect of a concrete slab on the top flange of a steel beam subject to lateral torsional buckling, two experimental load tests were performed. The first test is a so called reference test where a steel beam with lateral restraints at the supports only (fork conditions), was loaded in four point bending. In a second test, a single 1.2 m wide non-connected concrete slab was placed on a strip of rubber at mid span of the steel beam with the same support conditions. The tests were carried out on 7.2 m long IPE240, S235 beams subject to identical loading conditions. The test results have been compared with results obtained from Finite Element simulations and theoretical analyses. It was observed that the non-connected precast concrete slab, placed on top of the steel beam, performed as a lateral support against lateral torsional buckling such that the beam almost reached its full plastic mechanism capacity. This preliminary study shows promising results. Further research is planned to quantify the restraining effect of floor slabs on the lateral torsional buckling behaviour of steel floor beams.
DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
Structural components of aluminium alloys are relatively sensitive to local buckling, due to the ... more Structural components of aluminium alloys are relatively sensitive to local buckling, due to the thin walls usually applied in combination with he high strength over stiffness ratios. Well evaIuated verification models are available to check he resistance for local buckling at room temperature. For fire design, however, such verification models are not available in case of aluminium structures. Based on a finite element study, this paper gives a verification model for local buckling of aluminium alloy structural components when exposed to fire.
This paper gives an overview of the work necessary and underway for the next version of part 1-1-... more This paper gives an overview of the work necessary and underway for the next version of part 1-1- of Eurocode 3 on steel structures: EN 1993-1-1. The work is until now done by Working Group 1 of subcommittee CEN/TC250/SC3 and soon the Project Team will start working on the next version of EN 1993-1-1. WG1 collected a longlist of items that may need improvement and the recently carried out systematic review also yielded topics that need to be considered for the next version of EN 1993-1-1. The work of WG1 already resulted in amendments for EN 1993-1-1 which were accepted by CEN/TC250/SC3. It was decided to include these amendments in the next version of EN 1993-1-1, that is due in a few years. In this paper, an overview is given of the already accepted amendments. They concern among others several strength and stability related design rules.
Kipsteunen worden vaak toegepast bij op buiging belaste stalen liggers om de draagkracht te vergr... more Kipsteunen worden vaak toegepast bij op buiging belaste stalen liggers om de draagkracht te vergroten. Bij een kipsteun is de optimale positie daar waar de knikvorm de grootste uitbuiging vertoont. Soms kan een kipsteun niet optimaal worden geplaatst. Bovendien zijn kipsteunen niet volledig stijf maar ietwat flexibel. Kloppen de toetsingsregels voor kipstabiliteit bij niet-optimaal geplaatste enigszins flexibele kipsteunen
Hat-sections of thin-walled steel are subject to a concentrated load and a bending moment at an i... more Hat-sections of thin-walled steel are subject to a concentrated load and a bending moment at an interior support. For a large concentrated load and a small bending moment, two failure mechanisms can occur: the yield-arc and the rolling mechanisms. Research indicated that the corner radius has a strong influence on the failure mechanism to occur [1-2}. It has been investigated whether small strips of the hat-section cross-sections can be used to gather insight into the differences of the two failure mechanisms. For small corner radii, strip behaviour and section behaviour are comparable. For large corner radii, this is not the case. Finite element models have been used to describe the cross-sectional behaviour of hat-sections for varying corner radii. Relatively simple analytical models have been derived which determine the location of first yield in the cross-section's web and the cross-section's rigid-plastic behaviour. Except for the largest corner radius, analytical model...
Problem statement: The present study investigated with the application of a robust control scheme... more Problem statement: The present study investigated with the application of a robust control scheme to improve the performance of a simplified indirect field oriented for small power surface mounted Permanent Magnet (PM) synchronous actuators. Approach: The suggested model was implemented using a simplified state feedback with no need to measure the current values to compute the control algorithm. Results: The current values were estimated by an accurate prediction model estimated from real input/output data. The suggested control scheme was enabling the possibility to perform a position controller by using only a position sensor. Conclusion: The performance of the controller was evaluated and validated by digital simulation using SIMNON package and the usefulness of the suggested method was proved.
To perform geometrically and materially nonlinear analyses including imperfec-tions for steel bea... more To perform geometrically and materially nonlinear analyses including imperfec-tions for steel beam lateral torsional buckling, the size and shape of the geometric imperfec-tion can be obtained from EN 1993-1-1. The shape is prescribed as an initial bow along the weak axis of the section, excluding torsion of the cross-section. The shape of the imperfection can alternatively be taken equal to the lateral torsional buckling mode, including torsion. Sev-eral tables and formulas exist to determine the size of the imperfection. Different imperfection approaches were applied in finite element simulations to evaluate the lateral torsional nonlin-ear buckling resistances and to compare them to the results obtained with design rules.
In dit artikel is het belastinggeval wateraccumulatie beschouwd voor star en verend gesteunde lig... more In dit artikel is het belastinggeval wateraccumulatie beschouwd voor star en verend gesteunde liggers. Voor de star gesteunde liggers is een aantal basisbelastinggevallen geanalyseerd. In de praktijk komen verend gesteunde liggers vaak voor, bijvoorbeeld bij dakconstructies opgebouwd uit hoofdliggers en gordingen. Ook verend gesteunde liggers zijn geanalyseerd. Voor een dakconstructie bestaande uit hoofdliggers en gordingen is een stelsel van vergelijkingen afgeleid waarmee zowel een schatting kan worden gemaakt van de benodigde profielen in het voorontwerp, als een controleberekening ter verificatie van het belastinggeval wateraccumulatie. Dit allemaal zonder iteratieve berekeningsmethoden, om het mechanisme van wateraccumulatie zo helder mogelijk te illustreren.
In the Eurocode system, for fatigue design of bridges, the recommended partial factor for fatigue... more In the Eurocode system, for fatigue design of bridges, the recommended partial factor for fatigue traffic loads is set to 1. In this paper, the adequacy of this approach is investigated by performing a reliability analysis on two types of welded joint in a main girder of a steel motorway bridge. For this purpose, a weigh in motion measurement dataset belonging to a main Dutch motorway has been compared with the fatigue load model 4 of Eurocode EN 1991-2 with respect to the stress spectrum and the fatigue damage of two structural steel details. Several structural schemes have been considered to study the effect of the shape and length of the influence line. The distributions of the stochastic variables such as dynamic amplification, accuracy of the structural model, and future traffic trends have been estimated or taken from literature. Partial factors for fatigue loads have then been calibrated in such a way that the target reliability is obtained. The influence of each stochastic v...
This paper reports the on-going research into traditional timber frames at the Eindhoven Universi... more This paper reports the on-going research into traditional timber frames at the Eindhoven University of Technology (TU/e) in the Netherlands, see e.g. [1] for a paper presented at WCTE 2014. Traditional timber frames were common structures for centuries. They lost popularity due to high manufacturing costs and low rated perception related to durability and load carrying capacity. Today’s technology provides timber frames and especially connections with high precision at relatively low production costs. This, together with the fact that these structures are still appealing, result in an increasing popularity although, as shown in this paper, the load carrying capacity of the frame regarded as a sway system is (very) low. The realisation of traditional timber frames is still based on craftsmanship without knowledge about strength, stability and stiffness. Traditional portal frames as shown in figure 1 are analysed. The analyses of numerical and experimental results show the peg diamete...
Estimating and reducing uncertainty in fatigue test data analysis is a relevant task in order to ... more Estimating and reducing uncertainty in fatigue test data analysis is a relevant task in order to assess the reliability of a structural connection with respect to fatigue. Several statistical models have been proposed in the literature with the aim of representing the stress range vs. endurance trend of fatigue test data under constant amplitude loading and the scatter in the finite and infinite life regions. In order to estimate the safety level of the connection also the uncertainty related to the amount of information available need to be estimated using the methods provided by the theory of statistic. The Bayesian analysis is employed to reduce the uncertainty due to the often small amount of test data by introducing prior information related to the parameters of the statistical model. In this work, the inference of fatigue test data belonging to cover plated steel beams is presented. The uncertainty is estimated by making use of Bayesian and frequentist methods. The 5% quantile of the fatigue life is estimated by taking into account the uncertainty related to the sample size for both a dataset containing few samples and one containing more data. The S-N curves resulting from the application of the employed methods are compared and the effect of the reduction of uncertainty in the infinite life region is quantified.
An approximate hand method for estimating horizontal deflections in high-rise steel frames with f... more An approximate hand method for estimating horizontal deflections in high-rise steel frames with flexible beamcolumn connections subjected to horizontal loading is presented. The method is developed from the continuous medium theory for coupled walls which is expressed in non-dimensional structural parameters. It accounts for bending deformations in all individual members as well as axial deformations in the vertical members and is more accurate for very tall structures. Additional deformations in the beam-column connections contributing to the overall frame deformations are also included in the analysis. This reduction in the frame stiffness requires the nondimensional structural parameters to be modified. A closed solution of the differential equation for the cantilevered structure yields a rapid assessment of the influence of different types of connection on the overall behaviour. Results for structures that are uniform with height compare closely with results from stiffness matrix analyses.
The use of precast concrete floor slabs in steel framed structures is quite common. In the design... more The use of precast concrete floor slabs in steel framed structures is quite common. In the design of the steel beams, the lateral restraining effect of the precast concrete slab is normally safely neglected. However, the concrete slab will provide some horizontal restraint, even without special provisions such as dowels being present. It may even be that the restraint provided by the floor slab prevents lateral torsional buckling. To investigate the restraining effect of a concrete slab on the top flange of a steel beam subject to lateral torsional buckling, two experimental load tests were performed. The first test is a so called reference test where a steel beam with lateral restraints at the supports only (fork conditions), was loaded in four point bending. In a second test, a single 1.2 m wide non-connected concrete slab was placed on a strip of rubber at mid span of the steel beam with the same support conditions. The tests were carried out on 7.2 m long IPE240, S235 beams subject to identical loading conditions. The test results have been compared with results obtained from Finite Element simulations and theoretical analyses. It was observed that the non-connected precast concrete slab, placed on top of the steel beam, performed as a lateral support against lateral torsional buckling such that the beam almost reached its full plastic mechanism capacity. This preliminary study shows promising results. Further research is planned to quantify the restraining effect of floor slabs on the lateral torsional buckling behaviour of steel floor beams.
DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
Structural components of aluminium alloys are relatively sensitive to local buckling, due to the ... more Structural components of aluminium alloys are relatively sensitive to local buckling, due to the thin walls usually applied in combination with he high strength over stiffness ratios. Well evaIuated verification models are available to check he resistance for local buckling at room temperature. For fire design, however, such verification models are not available in case of aluminium structures. Based on a finite element study, this paper gives a verification model for local buckling of aluminium alloy structural components when exposed to fire.
This paper gives an overview of the work necessary and underway for the next version of part 1-1-... more This paper gives an overview of the work necessary and underway for the next version of part 1-1- of Eurocode 3 on steel structures: EN 1993-1-1. The work is until now done by Working Group 1 of subcommittee CEN/TC250/SC3 and soon the Project Team will start working on the next version of EN 1993-1-1. WG1 collected a longlist of items that may need improvement and the recently carried out systematic review also yielded topics that need to be considered for the next version of EN 1993-1-1. The work of WG1 already resulted in amendments for EN 1993-1-1 which were accepted by CEN/TC250/SC3. It was decided to include these amendments in the next version of EN 1993-1-1, that is due in a few years. In this paper, an overview is given of the already accepted amendments. They concern among others several strength and stability related design rules.
Kipsteunen worden vaak toegepast bij op buiging belaste stalen liggers om de draagkracht te vergr... more Kipsteunen worden vaak toegepast bij op buiging belaste stalen liggers om de draagkracht te vergroten. Bij een kipsteun is de optimale positie daar waar de knikvorm de grootste uitbuiging vertoont. Soms kan een kipsteun niet optimaal worden geplaatst. Bovendien zijn kipsteunen niet volledig stijf maar ietwat flexibel. Kloppen de toetsingsregels voor kipstabiliteit bij niet-optimaal geplaatste enigszins flexibele kipsteunen
Hat-sections of thin-walled steel are subject to a concentrated load and a bending moment at an i... more Hat-sections of thin-walled steel are subject to a concentrated load and a bending moment at an interior support. For a large concentrated load and a small bending moment, two failure mechanisms can occur: the yield-arc and the rolling mechanisms. Research indicated that the corner radius has a strong influence on the failure mechanism to occur [1-2}. It has been investigated whether small strips of the hat-section cross-sections can be used to gather insight into the differences of the two failure mechanisms. For small corner radii, strip behaviour and section behaviour are comparable. For large corner radii, this is not the case. Finite element models have been used to describe the cross-sectional behaviour of hat-sections for varying corner radii. Relatively simple analytical models have been derived which determine the location of first yield in the cross-section's web and the cross-section's rigid-plastic behaviour. Except for the largest corner radius, analytical model...
Problem statement: The present study investigated with the application of a robust control scheme... more Problem statement: The present study investigated with the application of a robust control scheme to improve the performance of a simplified indirect field oriented for small power surface mounted Permanent Magnet (PM) synchronous actuators. Approach: The suggested model was implemented using a simplified state feedback with no need to measure the current values to compute the control algorithm. Results: The current values were estimated by an accurate prediction model estimated from real input/output data. The suggested control scheme was enabling the possibility to perform a position controller by using only a position sensor. Conclusion: The performance of the controller was evaluated and validated by digital simulation using SIMNON package and the usefulness of the suggested method was proved.
To perform geometrically and materially nonlinear analyses including imperfec-tions for steel bea... more To perform geometrically and materially nonlinear analyses including imperfec-tions for steel beam lateral torsional buckling, the size and shape of the geometric imperfec-tion can be obtained from EN 1993-1-1. The shape is prescribed as an initial bow along the weak axis of the section, excluding torsion of the cross-section. The shape of the imperfection can alternatively be taken equal to the lateral torsional buckling mode, including torsion. Sev-eral tables and formulas exist to determine the size of the imperfection. Different imperfection approaches were applied in finite element simulations to evaluate the lateral torsional nonlin-ear buckling resistances and to compare them to the results obtained with design rules.
In dit artikel is het belastinggeval wateraccumulatie beschouwd voor star en verend gesteunde lig... more In dit artikel is het belastinggeval wateraccumulatie beschouwd voor star en verend gesteunde liggers. Voor de star gesteunde liggers is een aantal basisbelastinggevallen geanalyseerd. In de praktijk komen verend gesteunde liggers vaak voor, bijvoorbeeld bij dakconstructies opgebouwd uit hoofdliggers en gordingen. Ook verend gesteunde liggers zijn geanalyseerd. Voor een dakconstructie bestaande uit hoofdliggers en gordingen is een stelsel van vergelijkingen afgeleid waarmee zowel een schatting kan worden gemaakt van de benodigde profielen in het voorontwerp, als een controleberekening ter verificatie van het belastinggeval wateraccumulatie. Dit allemaal zonder iteratieve berekeningsmethoden, om het mechanisme van wateraccumulatie zo helder mogelijk te illustreren.
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