208 research outputs found
Ultimate load of randomly sampled stainless steel frames under gravity plus wind loads
No full text<p>Data was generated using the general purpose finite element software ABAQUS and performing advanced nonlinear analyses. The database is comprised of ultimate load factors corresponding to different random samples of six different nominal stainless steel frames under gravity and wind load combinations. The values of the random variable assignments are given for each case.</p>
<p>The full details of the finite element model can be found in: Arrayago, I.; Rasmussen, K.J.R.; Zhang, H. System-based reliability analysis of stainless steel frames subjected to wind loads. "Structural Safety", July 2022, vol. 97, art. No. 102211.</p>
<p>DOI: https://doi.org/10.1016/j.strusafe.2022.102211</p>
Stiffness of randomly sampled stainless steel frames under gravity and gravity plus wind load scenarios
No full text<p>Data was generated using the general purpose finite element software ABAQUS and performing advanced nonlinear analyses. The database is comprised of vertical and lateral system stiffness values corresponding to different random samples of six different nominal stainless steel frames under gravity and gravity plus wind load combinations. The values of the random variable assignments are given for each case. </p>
<p>The full details of the finite element model can be found in: Arrayago, I.; Rasmussen, K.J.R. Reliability of stainless steel frames designed using the Direct Design Method in serviceability limit states. Journal of Constructional Steel Research 196, 107425, 2022. DOI: https://doi.org/10.1016/j.jcsr.2022.107425</p>
<p>The data included in the dataset corresponds to the vertical & lateral stiffness of each frame under different load conditions.</p>
<p>Although the data has been generated using the finite element software ABAQUS, no special software is required to read or interpret the data.</p>
Interaction of geometric and material nonlinearities in stainless steel frames
No full textAdequate mechanical properties make stainless steel an excellent construction material for structures. The current stainless steel European structural code EN1993-1-4 (2015) is largely based on provisions given for carbon steel EN1993-1-1 (2005) and does not establish specific design rules for the global analysis of stainless steel structures. Thus, the same classification criterion applies in both codes for sway and non-sway structures, as well as providing the same predicting expressions for the amplification of bending moments in basic structures, despite the considerable differences between the mechanical behaviour of these two materials. However, recent numerical research on stainless steel frames with H cross-sections by Walport et al. (2019) showed that the degradation of stiffness due to material nonlinearities considerably affects the response of stainless steel frames, causing greater deformations and increasing second order effects. In order to contribute to the optimal design of stainless steel structures, this paper investigates the influence of the nonlinear material response of stainless steel alloys on frame-type structures with Rectangular Hollow Sections based on the experimental results conducted by Arrayago et al. (2019), and the interaction of material and geometric nonlinearities.The authors acknowledge the funding from MINECO (Spain) under Project BIA2016-75678-R, AEI/FEDER, UE “Comportamiento estructural de pórticos de acero inoxidable. Seguridad frente a ac-ciones accidentales de sismo y fuego”. The first author would also like to acknowledge the financial support provided by FPI-MINECO PhD fellowship Ref. BES-2017-082958. The second author would like to acknowledge the financial support received funding from the European Union’s Horizon 2020 research and innovation pro-gramme under the Marie Sklodowska-Curie grant agreement No. 842395.Postprint (published version
System-based reliability analysis of stainless steel frames under gravity loads
No full textCurrent structural codes for steel and stainless steel structures such as AISC 360-16, AISC 370-21, AS/NZS 4100 and Eurocode 3 are based on the traditional two-step member-based design approach, in which internal actions are first obtained from a structural analysis, usually elastic, and the strength of each member and connection is subsequently checked using a structural design standard. However, the most recent versions of these standards already incorporate preliminary versions of the direct, or one-step, system-based design alternative, which is based on the design-by-analysis concept and allows evaluating the strength of structures directly from numerical simulations, although the standards in their current form do not provide reliability requirements for structural systems. Therefore, it is necessary to build a rigorous structural reliability framework to investigate acceptable target reliability indices for structural systems and to provide adequate system safety factors and system resistance factors. While this framework has been developed based on advanced Finite Element analysis for hot-rolled and cold-formed carbon steel structures in recent years in the form of the Direct Design Method (DDM), the framework does not exist for stainless steel structures. This paper presents an extension of the DDM to the analysis of stainless steel structures, in which system reliability calibrations are presented for six stainless steel portal frames under gravity loads covering the three most common stainless steel families and different failure modes using advanced numerical simulations. From the derived reliability calibrations, suitable system safety factors and system resistance factors are proposed for the direct design of stainless steel frames in the European, US and Australian design frameworks under gravity loads
Tests on ferritic stainless steel simply supported and continuous SHS and RHS beams
No full textThis is the accepted version of the following article: [Arrayago, I., Real, E. and Mirambell, E. (2016), Tests on ferritic stainless steel simply supported and continuous SHS and RHS beams. Steel Construction, 9: 291–295. doi:10.1002/stco.201610033], which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/stco.201610033/fullDevelopment of efficient design guidance for stainless steel structures (considering non-linear behaviour, strain hardening and allowing for moment redistribution in indeterminate structures) is crucial for the widespread use of this corrosion-resistant material. This paper presents an experimental programme involving ferritic stainless steel simply supported and continuous beams (RHS and SHS) and the assessment of existing cross-sectional classifications and different plastic design methods available in the literature for indeterminate stainless steel structures, not currently allowed in stainless steel standards. The analysis indicated that some cross-sectional classification limits seem to be too optimistic for ferritic stainless steels and further research is needed in order to extend plastic design to these grades.Peer Reviewe
The Continuous Strength Method for the design of stainless steel members under combined loading
No full textThe Continuous Strength Method (CSM) provides accurate cross-section resistance predictions since allowance is made for the partial spread of plasticity and the beneficial effects of strain hardening. Although CSM design provisions for different loading conditions are available, the method was limited to the determination of cross-sectional resistance until recent research by Arrayago et al. (2020) proposed a consistent new approach to the design of stainless steel hollow section members subjected to compression. Extension of the CSM to the design of stainless steel members subjected to combined compression and bending moment is presented in this paper. The analysis is based on numerical results generated in the current study and existing results collected from the literature on stainless steel hollow section members. The results demonstrate that the adoption of the CSM design equations to predict column strength considerably improves the ac-curacy of the calculated beam-column capacities. The reliability of the proposed approach is demonstrated through statistical analyses performed in accordance with EN 1990.The authors acknowledge the funding from the MINECO (Spain) under Project BIA2016-75678-R, AEI/FEDER, UE “Comportamiento estructural de pórticos de acero inoxidable. Seguridad frente a acciones accidentales de sismo y fuego”. The first author would also like to acknowledge the financial support received from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 842395.Postprint (published version
Experimental load-displacement response of a stainless steel specimen under cyclic loading
No full text<p>Experimental load-displacement data was obtained by testing a autenitic stainless steel RHS member under cyclic bending around its major axis following a cantilever loading scheme. The database is comprised of the horizontal displacement measured by a string potentiometer attached at the free end of the specimen and the horizontal force introduced by the actuator. </p>
<p>The data corresponds to the specimen named S1-L1, which was an austenitic stainless steel RHS specimen, with a cross-section S1 (120 × 80 × 6 mm) and an effective length of L1 = 1650 mm. </p>
<p>The full details of the experimental test can be found in: González-de-León I., Nastri E., Arrayago I., Montuori R., Piluso V., Real E. Experimental study on stainless steel tubular members under cyclic loading. Thin-Walled Structures 181, 109969, 2022. DOI: https://doi.org/10.1016/j.tws.2022.109969.</p>
Reliability of stainless steel frames designed using the Direct Design Method in serviceability limit states
Get PDFSteel structures can be consistently and efficiently designed using system-based design-by-analysis approaches such as the Direct Design Method. However, since direct design approaches lead to potentially lighter structural configurations, they can also result in larger deformations under service loads. Thus, greater attention may be required to serviceability limit states in structures designed using design-by-analysis approaches than for structures designed elastically at their ultimate limit state following current two-stage approaches, especially for materials showing highly nonlinear stress vs strain responses such as stainless steel alloys. With the aim of investigating the influence of allowing larger deformations in the ultimate limit state design of stainless steel structures, this paper presents an explicit analysis framework for assessing serviceability reliability at system level. Using this framework, the paper investigates the serviceability reliability of cold-formed stainless steel portal frames designed using the Direct Design Method for different load cases, including the gravity load and the combined gravity plus wind load combinations. The study considers six baseline frames covering the most common stainless steel families and international design frameworks (i.e., Eurocode, US and Australian frameworks), for which the reliability of vertical deflection and lateral drift serviceability limit states is investigated using advanced numerical simulations and First-Order Reliability Methods. From the comparison of the calculated average annual reliability indices and the relevant target reliabilities for the different design frameworks, it was found that the reliability of stainless steel frames appears to be adequate for the serviceability limit states investigated for the Eurocode, US and Australian frameworks.Peer ReviewedPostprint (published version
System-based reliability analysis of stainless steel frames subjected to gravity and wind loads
Get PDFIn the process of developing the next generation of design standards for steel structures, most relevant international structural codes including AISC 360, AISC 370, AS/NZS 4100 and Eurocode 3 already incorporate preliminary versions of system-based design-by-analysis approaches that allow a direct evaluation of the strength of steel and stainless steel structures from advanced numerical simulations. As a result, recent research works have focused on building rigorous structural reliability frameworks to investigate acceptable target reliability indices for structural systems and to develop new design methods in conjunction with adequate system safety factors and system resistance factors. Although design recommendations exist for the direct design of hot-rolled and cold-formed steel structures based on advanced finite element analysis, the extension of the method to other materials such as stainless steel is under development. This paper is part of a research effort to build a reliability framework for stainless steel structures subject to different load combinations and presents the results of system reliability calibrations carried out on six stainless steel portal frames subjected to combined gravity and wind loads. The study covers the most common stainless steel families and three international design frameworks (i.e., Eurocode, US and Australian frameworks). From the reliability calibrations derived, suitable system safety factors and system resistance factors are proposed for the direct design of stainless steel frames under combined gravity and wind loads using advanced numerical simulations.The project leading to this research has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement No. 84239.Peer ReviewedPostprint (published version
Comportamiento estructural de vigas de acero inoxidable ferrítico frente a cargas concentradas
Get PDFLos elementos de acero conformados en frío son muy útiles dado su elevado ratio de resistencia/peso en comparación con otros materiales estructurales. Generalmente son elementos con valores elevados en ratios como altura/espesor y anchura/espesor, por lo que debe tenerse un especial cuidado en lo que se refiere a los fenómenos de inestabilidad, entre los que se encuentra el web crippling o abolladura del alma frente a cargas transversales localizadas. Por otra parte, los aceros inoxidables presentan, además de buenas características mecánicas, una excelente resistencia a la corrosión en distintos tipos de ambientes. De entre todos ellos, el acero inoxidable ferrítico cuenta con un precio estable en el mercado, debido a su bajo contenido en níquel, manteniendo unas magníficas prestaciones mecánicas. Por ello, los elementos conformados en frío de acero inoxidable ferrítico se presentan como elementos con un gran futuro como alternativa a los aceros inoxidables austeníticos. Dado que las especificaciones para elementos conformados en frío de acero inoxidable coinciden con las de los aceros al carbono y no cubren los aceros ferríticos, se están desarrollando proyectos para la elaboración de nuevas guías de diseño que permitan incluir los aceros inoxidables ferríticos y poder desarrollar técnicas de proyección eficientes. Este trabajo ha formado parte de uno de estos proyectos, estudiando el fenómeno de web crippling en aceros inoxidables en general, y en ferríticos en particular, para comprobar la aplicabilidad de las especificaciones existentes y la propuesta de nuevas expresiones
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