Academic literature on the topic 'Slenderness limits'
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Journal articles on the topic "Slenderness limits"
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Bradford, M. A., H. Y. Loh, and B. Uy. "Slenderness limits for filled circular steel tubes." Journal of Constructional Steel Research 58, no. 2 (February 2002): 243–52. http://dx.doi.org/10.1016/s0143-974x(01)00043-8.
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Marí, Antonio R., and Jostein Hellesland. "Lower Slenderness Limits for Rectangular Reinforced Concrete Columns." Journal of Structural Engineering 131, no. 1 (January 2005): 85–95. http://dx.doi.org/10.1061/(asce)0733-9445(2005)131:1(85).
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Rasmussen, K. J. R., and G. J. Hancock. "Plate slenderness limits for high strength steel sections." Journal of Constructional Steel Research 23, no. 1-3 (January 1992): 73–96. http://dx.doi.org/10.1016/0143-974x(92)90037-f.
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Elchalakani, M., X. L. Zhao, and R. H. Grzebieta. "Plastic Slenderness Limits for Cold-Formed Circular Hollow Sections." Australian Journal of Structural Engineering 3, no. 3 (January 1, 2002): 127–41. http://dx.doi.org/10.1080/13287982.2002.11464900.
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Sivakumaran, K. S., and Bing Yuan. "Slenderness limits and ductility of high strength steel sections." Journal of Constructional Steel Research 46, no. 1-3 (April 1998): 149–51. http://dx.doi.org/10.1016/s0143-974x(98)00158-8.
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King, C. M., and J. B. Davison. "Cross-section slenderness limits for columns with plastic rotations." Journal of Constructional Steel Research 95 (April 2014): 162–71. http://dx.doi.org/10.1016/j.jcsr.2013.11.019.
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Kaur, Ravpreet, and Harvinder Singh. "Slenderness in Steel Fibre Reinforced Concrete Long Beams." Civil Engineering Journal 8, no. 6 (June 1, 2022): 1240–56. http://dx.doi.org/10.28991/cej-2022-08-06-011.
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Slenderness influences in steel fibre reinforced concrete (SFRC) long beams are not adequately addressed in current concrete design regulations. The present guidelines are confined to semi-empirical formulations for limiting slenderness ratio, but largely restricted to RC beams. Many scholars have already examined RC long beams and successfully presented the slenderness ratio formula for RC long beams. This article proposes a novel term for limiting the slenderness ratio for SFRC long rectangular beams based on the fundamental principle of mechanics and taking into account the slenderness impact of RC long beams as well as the flexural moment capacity of SFRC beams. The suggested formulation for limiting slenderness ratio agrees closely with experimental data and may reliably forecast the mode of collapse. The proposed limiting slenderness ratio formulation takes into consideration beam end circumstances, loading conditions, concrete strengths, steel, tension and compression reinforcement ratios, and transverse reinforcement ratios, among other factors. It is revealed that a wide variety of slenderness limits may be achieved for varied sets of design parameters. The researchers' predictions and the suggested equation are compared to the test results of 9 SFRC beams. The suggested equation fits well with the results of the tests that have been done so far. Doi: 10.28991/CEJ-2022-08-06-011 Full Text: PDF
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Hellesland, Jostein. "Mechanics and Slenderness Limits of Sway-Restricted Reinforced Concrete Columns." Journal of Structural Engineering 134, no. 8 (August 2008): 1300–1309. http://dx.doi.org/10.1061/(asce)0733-9445(2008)134:8(1300).
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Kazemzadeh Azad, Sina, Dongxu Li, and Brian Uy. "Axial slenderness limits for austenitic stainless steel-concrete composite columns." Journal of Constructional Steel Research 166 (March 2020): 105856. http://dx.doi.org/10.1016/j.jcsr.2019.105856.
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KRAHL, P. A., M. C. V. LIMA, and M. K. EL DEBS. "Recommendations for verifying lateral stability of precast beams in transitory phases." Revista IBRACON de Estruturas e Materiais 8, no. 6 (December 2015): 763–74. http://dx.doi.org/10.1590/s1983-41952015000600003.
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Abstract This paper presents recommendations for security check of precast beams in transitory phases, compare results of parametric analyzes with national and international code recommendations and confront the formulations used for the calculation of critical load of lateral instability. In transport and lifting phases, precast beams are susceptible to loss lateral stability because the established supports provides little restriction to the element rotate on its principal axis and move laterally. To recommend limits of slenderness, parametric analysis are performed using formulations based on bifurcacional instability, including eigenvalue problems with the finite element method. The results show that the safety limits for I beams and rectangular beams are different. For the analyzed cases and with reference to beam slenderness equation used by fib Model Code [13], the limit determined for rectangular beams would be 85 and for I beams 53, which could be taken as 50, as recommended by the code. Within the analyzed cases of I beams, only the fib Model Code [13] recommendation attend the slenderness limit for transitory phases.
Dissertations / Theses on the topic "Slenderness limits"
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Krahl, Pablo Augusto. "Instabilidade lateral de vigas pré-moldadas em situações transitórias." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-14052014-104144/.
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O objetivo desta pesquisa é apresentar procedimentos de verificação da estabilidade lateral de vigas de concreto em situações transitórias e com eles realizar análises paramétricas. As fases transitórias estudadas são içamento, transporte e pré-serviço com e sem contraventamento nos apoios. As formulações apresentadas contém cálculo de carga crítica de instabilidade lateral, momento crítico e fator de segurança. São apresentados exemplos numéricos e a partir deles realizadas análises paramétricas com intuito de determinar limites de segurança. Os parâmetros variados foram fck, imperfeições geométricas, vão, largura da mesa comprimida e espessura da alma fazendo uma comparação entre vigas I e retangular. Com os resultados, foram obtidas esbeltezes geométricas limite para fases transitórias, relações entre carga crítica e carga devido ao peso próprio e uma relação entre momento crítico elástico e momento último de flexão para a fase transitória anterior à execução do tabuleiro com contraventamento nos apoios, especificamente. Na comparação entre vigas I e retangular, constatou-se que os dois tipos de seção apresentam limites de segurança distintos. As análises mostraram que os limites de esbeltez geométrica recomendados, como lh/bf², geram elementos, de seção transversal I, muito esbeltos. Este parâmetro apresentou uma variação significativa na tentativa de determinar limites nas análises paramétricas. Portanto, pode ser conservador adotar como limite a menor esbeltez obtida nas análises. Conclui-se que a verificação da segurança por esbeltezes geométricas nem sempre é adequada, pois não são considerados parâmetros como imperfeições geométricas e fck que mostraram serem importantes nas análises paramétricas. A esbeltez representada pela razão entre momento último e momento crítico de instabilidade elástico é mais abrangente e a busca por um valor limite deste parâmetro apresentou resultados com pouca variação para as vigas I. Com relação ao limite clássico de segurança que recomenda uma carga crítica maior que quatro vezes a carga de peso próprio, os resultados mostraram que esta recomendação é conservadora. As análises paramétricas mostraram que para vigas I esta razão igual a dois e meio atende a segurança destes elementos.The objective of this research is to present a contribution to the verification of lateral stability of concrete beams in transient situations through parametric analyzes. The transient phases studied are lifting, transportation and prior to execution of the deck with braced and unbraced supports. Formulations presented contain calculation of buckling load, buckling moment and factor of safety. Numerical examples are presented and parametric analyzes are performed from these aiming to determine safety limits. The varied parameters were fck, geometric imperfections, span, compression flange width and web width by making a comparison between I-beams and rectangular beams. With the results, slenderness limits were obtained for transient phases, relationships between critical load and load due to self-weight and a relationship between elastic critical moment and ultimate moment to the transient situation before the execution of the deck with braced supports, specifically. In the comparison between I-beams and rectangular beams, it was found that the two types of section present different safety limits. Analyzes showed that the geometric slenderness limits recommended, as lh/bf², generate slender elements of I cross section. This parameter showed a significant variation in an attempt to determine limits on parametric analyzes. Therefore adopt the lower slenderness limit obtained in analyzes may be conservative. It is concluded that the safety verification by geometric slenderness is not always adequate, because they do not consider parameters such as geometric imperfections and fck that showed to be important in the parametric analyzes. The slenderness ratio represented by the ultimate moment and elastic critical moment of instability is more comprehensive and the search for a limiting value of this parameter presented results with little variation for the I-beams. With respect to the classical limit of safety which recommends that the critical load is greater than four times the self-weight load, the results showed that this recommendation is conservative. Parametric analyzes showed that for I-beams this ratio equal to two and a half addresses the safety of these elements.
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Kazemzadeh, Azad Sina. "Behaviour and Design of Fabricated Concrete-Filled Stainless Steel Tubular Columns." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/25008.
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The present thesis starts by investigating the local and post-local buckling behaviour of fabricated box and circular concrete-filled stainless steel tubes (CFSSTs) as well as stainless steel partially-encased I-sections. A comprehensive set of experiments considering austenitic, duplex, and lean duplex stainless steel grades is carried out followed by an extensive numerical parametric study. The results are then summarised to propose, for the first time, axial slenderness limits and effective width/diameter formulae for the studied section types.
The investigation on the local stability is extended in the next part of the thesis where a comprehensive numerical study is conducted to clarify the role of concrete infill in the local buckling behaviour of circular tubes. The results strongly suggest that the concrete infill has limited effect on enhancing the local buckling strength of circular tubes. The enhancement is found to be much lower than that implied in international design standards. The roots for this discrepancy are identified and it is suggested that the axial slenderness limit for hollow circular tubes can be significantly relaxed to bring it closer to that of filled circular tubes.
The final part of the thesis focuses on the response of compact and slender box CFSSTs under axial and flexural actions. An experimental programme is first carried out comprising compact and slender CFSSTs fabricated from austenitic and lean duplex plates. Stub columns under axial compression as well as combined compression and bending, CFSST beams under pure bending, and long CFSST columns under axial compression are all included in the experiments. The tests are followed by an extensive numerical study. Outcomes of the investigations are then synthesised to develop comprehensive procedures for the design of compact and slender box CFSSTs under compression, bending, and combined loading. Such procedures have not yet been established for CFSSTs in international design standards.
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Huang, Zhichao. "Behaviour and design of steel-concrete composite columns incorporating high-performance materials." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/24993.
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Composite columns with high-performance materials have gained increasing attention over the past decades. The use of high-performance materials in composite columns can minimise a cross-section area and self-weight for structural components, with consequent savings in materials and labour work. The major scope of this thesis is to investigate the structural behaviour of steel-concrete composite columns incorporating high-performance materials, which can promote the adoption of such composite columns in construction industry. Two major parts are included in this thesis: the first part is to define the section slenderness limits and local and post-local buckling behaviour of high-performance composite columns; the second part is to investigate the load bearing capacities of concrete-filled steel tubular columns subjected to axial compression, flexural bending as well as combined axial and flexural loads.
The first part of the thesis reports a test programme consisting of 32 hollow and composite short columns, of which half are fabricated with high-strength steel (S690) and the other half with ultra-high-strength steel (S960). The primary parameter considered in the test programmes is the slenderness (b/t) of steel plates, specifically, the component plates of square sections and flange outstands of I-sections. The prepared composite columns were tested under axial compression, which was applied to steel sections only. The concrete infills, if any, only restrained the component plates from inward buckling. Failure modes, load-axial shortening response and axial strain development were analysed. Non-linear finite element models were developed and validated against the experimental results, which was used to investigate the section slenderness limits and post-local buckling behaviour of high-performance columns. The developed numerical models allowed for residual stresses and initial geometric imperfections being considered. With the
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obtained experimental and numerical results, existing international design provisions for steel and composite columns were evaluated. Accordingly, recommendations for the section slenderness limits and post-local buckling strength of high-performance columns were suggested.
The second part of the thesis elaborates an experimental program on the axial and flexural behaviour of concrete-filled steel tubular (CFST) columns utilising ultra-high-strength steel (S960) and high-strength concrete (C70 and C100). The effects of concrete strength, load eccentricity and member slenderness (Le/r) on axial and flexural resistance, initial stiffness and ductility were assessed. With the obtained experimental results, finite element models were developed and validated, which accurately predicted the axial and flexural behaviour of the CFST columns. A series of parameters, including steel strength, concrete strength and plate slenderness, were evaluated through parametric studies. A commentary on existing standard provisions for CFST columns was provided based on the acquired experimental and numerical results.
Based on the results obtained from this thesis, the slenderness limits and optimal approaches for post-local buckling strength of hollow and composite columns have been recommended, which are applicable to the steel grades ranging from 250 to 960 MPa. With the presence of concrete infills, the slenderness limits and post-local buckling strength are significantly improved. In addition, existing standard provisions for hollow and composite columns have been evidenced to be safe for the design of high-performance hollow and composite columns if the recommended slenderness limits and design curves can be adopted.
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Wilkinson, Timothy James. "The Plastic Behaviour of Cold-Formed Rectangular Hollow Sections." University of Sydney. Department of Civil Engineering, 2000. http://hdl.handle.net/2123/843.
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The aim of this thesis is to assess the suitability of cold-formed rectangular hollow sections (RHS) for plastic design. The project involved an extensive range of tests on cold-formed Grade C350 and Grade C450 (DuraGal) RHS beams, joints and frames. A large number of finite element analyses was also carried out on models of RHS beams. The conclusion is that cold- formed RHS can be used in plastic design, but stricter element slenderness (b/t) limits and consideration of the connections, are required. Further research, particularly into the effect of axial compression on element slenderness limits, is required before changes to current design rules can be finalised. Bending tests were performed on cold-formed RHS to examine the web and flange slenderness required to maintain the plastic moment for a large enough rotation suitable for plastic design. The major conclusions of the beam tests were: (i) Some sections which are classified as Compact or Class 1 by current steel design specifications do not maintain plastic rotations considered sufficient for plastic design. (ii) The current design philosophy, in which flange and web slenderness limits are independent, is inappropriate. An interaction formula is required, and simple formulations are proposed for RHS. Connection tests were performed on various types of knee joints in RHS, suitable for the column - rafter connection in a portal frame. The connection types investigated were welded stiffened and unstiffened rigid knee connections, bolted plate knee joints, and welded and bolted internal sleeve knee joints, for use in RHS portal frames. The ability of the connections to act as plastic hinges in a portal frame was investigated. The most important finding of the joint tests was the unexpected fracture of the cold-formed welded connections under opening moment before significant plastic rotations occurred. The use of an internal sleeve moved the plastic hinge in the connection away from the connection centre- line thus eliminating the need for the weld between the RHS, or the RHS and the stiffening plate, to carry the majority of the load. The internal sleeve connections were capable of sustaining the plastic moment for large rotations considered suitable for plastic design. Tests on pinned-base portal frames were also performed. There were three separate tests, with two different ratios of vertical to horizontal point loads, simulating gravity and horizontal wind loads. Two grades of steel were used for comparison. The aims of the tests were to examine if a plastic collapse mechanism could form in a cold-formed RHS frame, and to investigate if plastic design was suitable for such frames. In each frame, two regions of highly concentrated curvature were observed before the onset of local buckling, which indicated the formation of plastic hinges and a plastic collapse mechanism. An advanced plastic zone structural analysis which accounted for second order effects, material non-linearity and member imperfections slightly overestimated the strength of the frames. The analysis slightly underestimated the deflections, and hence the magnitude of the second order effects. A second order plastic zone analysis, which did not account for the effects of structural imperfections, provided the best estimates of the strengths of the frames, but also underestimated the deflections. While cold-formed RHS did not satisfy the material ductility requirements specified for plastic design in some current steel design standards, plastic hinges and plastic collapse mechanisms formed. This suggests that the restriction on plastic design for cold-formed RHS based on insufficient material ductility is unnecessary, provided that the connections are suitable for plastic hinge formation, if required. A large number of finite element analyses were performed to simulate the bending tests summarised above, and to examine various parameters not studied in the experimental investigation. To simulate the experimental rotation capacity of the RHS beams, a sinusoidally varying longitudinal local imperfection was prescribed. The finite element analysis determined similar trends as observed experimentally, namely that the rotation capacity depended on both the web slenderness and flange slenderness, and that for a given section aspect ratio, the relationship between web slenderness and rotation capacity was non-linear. The main finding of the finite element study was that the size of the imperfections had an unexpectedly large influence on the rotation capacity. Larger imperfections were required in the more slender sections to simulate the experimental results. There should be further investigation into the effect of varying material properties on rotation capacity.
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Wilkinson, Timothy James. "The Plastic Behaviour of Cold-Formed Rectangular Hollow Sections." Thesis, The University of Sydney, 1999. http://hdl.handle.net/2123/843.
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The aim of this thesis is to assess the suitability of cold-formed rectangular hollow sections (RHS) for plastic design. The project involved an extensive range of tests on cold-formed Grade C350 and Grade C450 (DuraGal) RHS beams, joints and frames. A large number of finite element analyses was also carried out on models of RHS beams. The conclusion is that cold- formed RHS can be used in plastic design, but stricter element slenderness (b/t) limits and consideration of the connections, are required. Further research, particularly into the effect of axial compression on element slenderness limits, is required before changes to current design rules can be finalised. Bending tests were performed on cold-formed RHS to examine the web and flange slenderness required to maintain the plastic moment for a large enough rotation suitable for plastic design. The major conclusions of the beam tests were: (i) Some sections which are classified as Compact or Class 1 by current steel design specifications do not maintain plastic rotations considered sufficient for plastic design. (ii) The current design philosophy, in which flange and web slenderness limits are independent, is inappropriate. An interaction formula is required, and simple formulations are proposed for RHS. Connection tests were performed on various types of knee joints in RHS, suitable for the column - rafter connection in a portal frame. The connection types investigated were welded stiffened and unstiffened rigid knee connections, bolted plate knee joints, and welded and bolted internal sleeve knee joints, for use in RHS portal frames. The ability of the connections to act as plastic hinges in a portal frame was investigated. The most important finding of the joint tests was the unexpected fracture of the cold-formed welded connections under opening moment before significant plastic rotations occurred. The use of an internal sleeve moved the plastic hinge in the connection away from the connection centre- line thus eliminating the need for the weld between the RHS, or the RHS and the stiffening plate, to carry the majority of the load. The internal sleeve connections were capable of sustaining the plastic moment for large rotations considered suitable for plastic design. Tests on pinned-base portal frames were also performed. There were three separate tests, with two different ratios of vertical to horizontal point loads, simulating gravity and horizontal wind loads. Two grades of steel were used for comparison. The aims of the tests were to examine if a plastic collapse mechanism could form in a cold-formed RHS frame, and to investigate if plastic design was suitable for such frames. In each frame, two regions of highly concentrated curvature were observed before the onset of local buckling, which indicated the formation of plastic hinges and a plastic collapse mechanism. An advanced plastic zone structural analysis which accounted for second order effects, material non-linearity and member imperfections slightly overestimated the strength of the frames. The analysis slightly underestimated the deflections, and hence the magnitude of the second order effects. A second order plastic zone analysis, which did not account for the effects of structural imperfections, provided the best estimates of the strengths of the frames, but also underestimated the deflections. While cold-formed RHS did not satisfy the material ductility requirements specified for plastic design in some current steel design standards, plastic hinges and plastic collapse mechanisms formed. This suggests that the restriction on plastic design for cold-formed RHS based on insufficient material ductility is unnecessary, provided that the connections are suitable for plastic hinge formation, if required. A large number of finite element analyses were performed to simulate the bending tests summarised above, and to examine various parameters not studied in the experimental investigation. To simulate the experimental rotation capacity of the RHS beams, a sinusoidally varying longitudinal local imperfection was prescribed. The finite element analysis determined similar trends as observed experimentally, namely that the rotation capacity depended on both the web slenderness and flange slenderness, and that for a given section aspect ratio, the relationship between web slenderness and rotation capacity was non-linear. The main finding of the finite element study was that the size of the imperfections had an unexpectedly large influence on the rotation capacity. Larger imperfections were required in the more slender sections to simulate the experimental results. There should be further investigation into the effect of varying material properties on rotation capacity.
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Palamadai, Subramanian Lakshmi Priya. "Flexural resistance of longitudinally stiffened plate girders." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54436.
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AASHTO LRFD requires the use of longitudinal stiffeners in plate girder webs when the web slenderness D/tw is greater than 150. This practice is intended to limit the lateral flexing of the web plate during construction and at service conditions. AASHTO accounts for an increase in the web bend buckling resistance due to the presence of a longitudinal stiffener. However, when the theoretical bend buckling capacity of the stiffened web is exceeded under strength load conditions, the Specifications do not consider any contribution from the longitudinal stiffener to the girder resistance. That is, the AASHTO LRFD web bend buckling strength reduction factor Rb applied in these cases is based on an idealization of the web neglecting the longitudinal stiffener. This deficiency can have significant impact on girder resistance in regions of negative flexure. This research is aimed at evaluating the improvements that may be achieved by fully considering the contribution of web longitudinal stiffeners to the girder flexural resistance.
Based on refined FE test simulations, this research establishes that minimum size longitudinal stiffeners, per current AASHTO LRFD requirements, contribute significantly to the post buckling flexural resistance of plate girders, and can bring as much as a 60% increase in the flexural strength of the girder. A simple cross-section Rb model is proposed that can be used to calculate the girder flexural resistance at the yield limit state. This model is developed based on test simulations of straight homogenous girders subjected to pure bending, and is tested extensively and validated for hybrid girders and other limit states.
It is found that there is a substantial deviation between the AISC/AASHTO LTB resistance equations and common FE test simulations. Research is conducted to determine the appropriate parameters to use in FE test simulations. Recommended parameters are identified that provide a best fit to the mean of experimental data. Based on FE simulations on unstiffened girders using these recommended parameters, a modified LTB resistance equation is proposed. This equation, used in conjunction with the proposed Rb model also provides an improved handling of combined web buckling and LTB of longitudinally stiffened plate girders.
It is observed that the noncompact web slenderness limit in the Specifications, which is an approximation based on nearly rigid edge conditions for the buckling of the web plate in flexure is optimistic for certain cross-sections with narrow flanges. This research establishes that the degree of restraint at the edges of the web depend largely on the relative areas of the adjoining flanges and the area of the web. An improved equation for the noncompact web slenderness limit is proposed which leads to a better understanding and representation of the behavior of these types of members.
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Ghavamian, Shahrokh. "Méthode simplifiée pour la simulation du comportement sismique des structures en béton armé : traitement des effets de l'élancement et estimateur d'erreurs." Cachan, Ecole normale supérieure, 1998. http://www.theses.fr/1998DENS0007.
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Le traitement en dynamique non linéaire du fonctionnement des structures en b. A. Est un problème complexe et couteux. L'aborder par des méthodes simplifiées est une solution avantageuse, a la condition de pouvoir conserver une description fine et réaliste des phénomènes majeurs. Analyse dans l'environnement d'une méthode par éléments finis multicouches, il a porte sur deux aspects majeurs : celui du traitement de l'élancement et celui de l'évaluation des erreurs liées a la discrétisation. Le code de calcul eficos initialement conçu avec des éléments poutres de type Navier-Bernoulli composés de couches superposées, permettait d'étudier le comportement d'un grand nombre d'éléments structuraux de type poutre/poteau, tant que leur élancement ne posait pas de difficultés particulières. La stratégie proposée ici permet de prendre en considération les effets de moment du second ordre. Ceci ajoute aux précédents travaux réalises sur les effets de cisaillement conduisent a un nouvel outil adapte, vis-à-vis de l'élancement, a un large domaine d'applications. S'agissant des grands déplacements, la méthode proposée, pour la prise en compte de l'effet p-delta en comportement en dommageable, a été appliquée au cas de poteaux en béton charges jusqu'a la ruine ; la comparaison avec l'expérience montre l'efficacité de la méthode. Des applications en réponse non linéaire sismique de piles de montre la capacité de l'outil à reproduire les principaux aspects critiques relatifs a la double non linéarité, matérielle et géométrique. Du cote des faibles élancements, l'étude réalisée dans le cadre du benchmark nupec met en évidence la bonne performance de la stratégie de modélisation simplifiée proposée, pour un mur arme de très faible élancement (inferieur a 1). Cependant, la qualité des résultats, notée par les organisateurs du benchmark comme étant de même niveau que ceux obtenus en éléments finis 2d ou 3 d, doit être associée à une représentation adaptée des conditions aux limites. L'étude est complétée par la proposition d'un estimateur d'erreurs dont la pertinence vis-a-vis de la discrétisation en éléments finis est montrée, aussi bien en statique qu'en dynamique. Une corrélation énergétique est également mise en évidence. C'est un nouveau pas vers l'optimisation et la fiabilité des analyses.
Book chapters on the topic "Slenderness limits"
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Khorramian, Koosha, Pedram Sadeghian, and Fadi Oudah. "A Preliminary Reliability-Based Analysis for Slenderness Limit of FRP-Reinforced Concrete Columns." In 8th International Conference on Advanced Composite Materials in Bridges and Structures, 91–98. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-09632-7_11.
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Carpinteri, Alberto. "Limit Analysis for Elastic-Softening Structures: Scale and Slenderness Influence on Global Brittleness." In Brittle Matrix Composites 1, 497–508. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4319-3_33.
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Su, M., B. Young, and L. Gardner. "Assessment of Eurocode 9 slenderness limits for elements in compression." In Tubular Structures XV, 569–74. CRC Press, 2015. http://dx.doi.org/10.1201/b18410-84.
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Zhao, X., A. Kernot, J. Packer, and T. Haque. "Slenderness limits for EHS and OHS subject to bending using the RHS approach." In Tubular Structures XIII, 293–301. CRC Press, 2010. http://dx.doi.org/10.1201/b10564-41.
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Gonzalo, José Carlos Palacios. "Islamic Stereotomy in Cairo." In Advances in Media, Entertainment, and the Arts, 523–48. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-5225-0029-2.ch022.
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A great number of mosques, madrassas and hospitals compete with the enormous mausolea of the two gigantic historical necropolis of Cairo. The extraordinary Cairene domes have been the subject of really interesting studies. From the early historiography investigations to the most recent contributions, some of them focused on finding an explanation to the stability of these constructions of extraordinary slenderness. However, the remarkable stereotomy of these constructions has only been mentioned in a few of these publications. The art of stonecutting requires geometric knowledge which, although it starts with the professional practice at the workshop associated to the job, reaches extraordinary complexity and abstraction levels. In Islam, the passion for geometry finds in the masonry art a field where it can be developed without limits.
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"Optimum Design of Reinforced Concrete Columns." In Metaheuristic Approaches for Optimum Design of Reinforced Concrete Structures, 92–115. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-2664-4.ch004.
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In the design of reinforced concrete (RC) columns, ductility is provided by allowing yielding of steel in the part of section under tensile stresses. This situation cannot be provided for RC columns since sections of columns are generally under compressive stresses resulting from axial loading including weight of all upper stories, flexural moments, and shear forces. To practically provide ductility, axial force is limited, and stirrups are densely designed. These rules are given in design regulations and must be checked during optimization. In this chapter, an optimum design methodology for biaxial loaded column is presented. Uniaxial loaded column methodology is given with the computer code. Finally, the slenderness effects are presented via ACI 318: Building code requirements for structural concrete and optimum results are given for several numerical cases using various metaheuristic algorithms.
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Reddy, S., and A. Stuedlein. "Effect of slenderness ratio on the reliability-based serviceability limit state design of augered cast-in-place piles." In Geotechnical Safety and Risk IV, 305–10. CRC Press, 2013. http://dx.doi.org/10.1201/b16058-44.
Full textConference papers on the topic "Slenderness limits"
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Slocum, Richard, Daniel Beard, and Grant Cleveland. "Not So Good Vibrations—Design Considerations for Slenderness Limits." In Electrical Transmission and Substation Structures 2022. Reston, VA: American Society of Civil Engineers, 2022. http://dx.doi.org/10.1061/9780784484463.008.
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Wang, Peter Y., Maria E. Garlock, Theodore P. Zoli, and Spencer E. Quiel. "Low-Frequency Sine Webs for Improved Shear Buckling Performance of Plate Girders." In IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.0691.
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<p>Steel plate girders are used extensively in buildings and bridges. Given shear rarely governs, minimizing web thickness is desirable. However, web slenderness can enable shear buckling and fatigue problems. The traditional strategy is to use welded transverse stiffeners; yet transversely-stiffened girders are prone to fatigue cracks and difficult to fabricate at high slenderness ratios. Thus, AASHTO currently limits web slenderness to 150. Alternatively, corrugated web girders overcome these deficiencies but require robotic welding for the web-to-flange weld. Corrugated webs are also limited to small web thicknesses (6mm or less) and girder depths (less than 1.5m) given web forming limits. The authors propose an alternative web geometry, introducing low-frequency sinusoids (LFS) in the web along its length. The LFS web can be welded to the flanges using semi-automatic weld techniques currently employed by bridge fabricators. The reduced web curvature allows for a wider array of web forming techniques with much larger plate thicknesses. In a finite element study, web geometric properties such as sinusoidal frequency and amplitude are varied. Results demonstrate a significant increase in the elastic shear buckling load and ultimate strength using a wavelength equal to the depth of the girder. The results of this study show promise for improved girder durability paired with material efficiency, demonstrating that a web product with constant amplitude and wavelength could work for various girder depths up to 3m and above.</p>
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Lui´s, Rui M., Malgorzata Witkowska, and C. Guedes Soares. "Ultimate Strength of Transverse Plate Assemblies Under Uniaxial Loads." In 25th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/omae2006-92664.
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This paper deals with the strength of panels composed of three and five plates connected transversely and loaded along the longitudinal direction. First, a comparison between the strength of panels having asymmetric imperfections and of single plates is made, which allows evaluating the ability of the single plate to properly simulate the panel strength. Following this, the results obtained for a panel model having symmetric imperfections are confronted with the results of the asymmetric imperfections. The asymmetrical and symmetrical models of the panel give respectively the lowest and highest strengths possible (imperfections in adjacent plates with different amplitudes have “in between” strengths) allowing to establish limits to the variation of the strength. The results show that using a single plate can be conservative or nonconservative, depending of the plate slenderness and shape of initial deflections. It is concluded that for design purposes it will in general be enough to consider assemblies of three plates, as the results for five plate assemblies are not much different.
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Şen, Pelin Keskin, Buse Bozkaplan, and Berra Gültekin Sınır. "Stability of Euler-Bernoulli Beams with Geometric Imperfection." In 6th International Students Science Congress. Izmir International Guest Student Association, 2022. http://dx.doi.org/10.52460/issc.2022.018.
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In this study, we have focused on slightly curved beams which can be used in various fields such as bridges, sensors, pipes, roofs etc. Beams with curvature can be classified as slightly curved or curved only. In slightly curved beams, curvature and beam’s displacement are considered in the same order. Thus, the variation of the moment of inertia due to curvature are ignored. Slightly curved beams are commonly called beams with geometric imperfection or shallow curved beams in the literature. We have discussed the geometric imperfection, in other words the slight curvature, in beam kinematics both in displacement and rotation of the section [3]. While obtaining the mathematical model, we have preferred approach Newton's second law of motion instead of the energy approach. For this purpose, we obtain a mathematical model based on the balance of loads acting on differential element. In literature, the energy principle is commonly used to derive the mathematical model of a slightly curved beam. In our literature scanning, using the vector approach which is called Newton’ second law to obtain the governing equation is firstly used with these beam kinematic assumptions. The dimensionless form of the resulting equation is as obtained. It is solved to provide hinged-hinged support conditions. Thus, the critical load value and the post-buckling graph are obtained depending on the displacement. As a result of the solutions, stability limits depending on slenderness coefficient, curvature amplitude and axial load are determined.
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Jian Yao and Zhegang Lu. "Slenderness limit for hybrid FRP-concrete-steel double-skin tubular columns." In 2011 Second International Conference on Mechanic Automation and Control Engineering (MACE). IEEE, 2011. http://dx.doi.org/10.1109/mace.2011.5988614.
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Kim, Sang-Hyun, Jae-Jun Han, and Yun-Jae Kim. "Mismatch Limit Loads of Circumferential Cracked Pipes With V-Groove Welds." In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-98127.
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The present work reports mis-match limit loads for V-groove welded pipe for a circumferential crack using finite element (FE) analyses. In our previous paper [14], closed-form solutions of mis-match limit loads were proposed for idealized butt weld configuration as a function of the strength mis-match ratio with only one geometry-related slenderness parameter. To integrate the effect of groove angles on mis-match limit loads, the geometry-related slenderness parameter has to be modified by relevant geometric parameters including groove angle, crack depth and root opening based on plastic deformation patterns in theory of plasticity. Circumferential through-wall cracks are located at the centre of the weld considering two different groove angles (45°, 90°). With regards to loading conditions, axial (longitudinal) tension is applied for all cases. For the parent and weld metal, elastic-perfectly plastic materials are used to simulate under-matching and over-matching conditions in plasticity. The overall results from the proposed solutions agree well with FE results.
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Ringsberg, Jonas W., Niklas Blomgren, and Matej Prevc. "Ultimate Limit State Analysis of FRP Composite Sandwich Plates: Development of a Semi-Analytical Method." In ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/omae2016-54069.
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The development of Sandwich PULS, a semi-analytical calculation tool for predicting the ultimate limit state (ULS) of FRP composite sandwich plates is presented. This was done by extending DNV GL’s semi-analytical calculation tool Composite PULS, which is used for quick estimation of the ULS for unstiffened composite plates. ULS was evaluated in terms of the first buckling load and the first ply failure (FPF). The Sandwich PULS code was developed by implementing formulations for sandwich plate theory. First-order shear deformation theory (FSDT) was implemented to include the transverse shear deformations that are highly important for sandwich plates with poor shear stiffness of the core. The Sandwich PULS code was evaluated against nonlinear finite element analyses (FEA). It was concluded that Sandwich PULS shows good agreement with FEA-predicted critical buckling loads. For all inspected plates, Sandwich PULS shows improved results compared to Composite PULS. Differences between Sandwich PULS and FEA are caused by the difference in evaluating shear stiffness. It has been shown that neglecting shear stiffness of faces results in good agreement between Sandwich PULS and FEA, while use of conventional shear correction factors proved to be unfavourable for sandwich plates. It was found that Sandwich PULS is limited in terms of slenderness. Sandwich plates with soft core should not have slenderness below 20 to assure an accurate solution.
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Kim, Sang-Hyun, Jae-Jun Han, Han-Sang Lee, and Yun-Jae Kim. "Effect of Weld Geometry on Mis-Match Limit Load Analyses for Circumferential Surface Cracked Pipes in the Centre of Welds." In ASME 2014 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/pvp2014-28865.
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The weld metal compared to the base metal, is known to be more vulnerable to cracking. Thus, the strength mismatch limit load analysis is necessary for defect assessment. In our previous paper, closed-form solutions of mis-match limit loads were proposed for idealized butt weld configuration as a function of the strength mis-match ratio with geometry-related slenderness parameter. The actual weld geometry is not idealized band configuration but shape of V-grooved welds. The surface crack is more common and significant than through wall crack. The present work provides mis-match limit loads for circumferential surface cracked pipes in the centre of V-groove welds using finite element (FE) analysis. Various crack depth (a/t=0.35∼0.8) and groove angles (20°∼90°) are considered for systematic investigation. With regards to loading conditions, axial tension is applied for all cases.
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Adib, Shady, and Ieva Misiunaite. "High strength steel cold-formed hollow sections: implication of cross-section aspect ratio and slenderness characteristics on flexural behavior." In The 13th international scientific conference “Modern Building Materials, Structures and Techniques”. Vilnius Gediminas Technical University, 2019. http://dx.doi.org/10.3846/mbmst.2019.066.
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Cold-formed tubular sections are widely applicated for a variety of structural solutions, primarily due to their advantageous structural properties, inherent aesthetic characteristics and ease of prefabrication and mass production. High strength steels (HSS) are attaining growing attention from structural engineers and researchers due to their potential on the design of lightweight and more economic structures. In combination with cold-formed tubular sections HSS might serve as improvement on structural efficiency as well as solution for structural problems when usage of normal steel is limited due to insufficient strength. However, innovative structural solutions are often faced problems related with absence of appropriate design procedures. In most of the design codes cross-section design is performed following the traditional classification procedure based on the slenderness of the individual constituents without respect to their interaction. Moreover, tubular sections are generally treated in the same manner without respect to their formation route, embedding an elastic-perfectly plastic material model, without reference to the cold-formed sections increased strength and reduced ductility over the flat material. This paper reports on the numerical study of cold-formed HSS tubular beams deformation response, with a focus on the effect of cross-section constituent’s interaction and strength enhancement influence on the cross-section slenderness. Finite element (FE) models were first developed and validated against existing test results. Upon validation against the experimental results, parametric studies were carried out to expand the available flexural response data over a range of cross-section aspect ratio, cross-section slenderness and steel grades. The obtained numerical results were used to assess the suitability of the current design codes cross-sections classification for cold-formed HSS tubular beams.
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Paik, Jeom Kee, Bong Ju Kim, Sung Kuk Park, Do Kyun Kim, Chang Hee Park, Dong Hee Park, and Bong Suk Jang. "On the Crashworthiness of Steel-Plated Structures in an Arctic Environment: An Experimental and Numerical Study." In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20760.
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The aim of this study is to investigate the crashworthiness characteristics of steel-plated structures subject to low temperatures that are equivalent to the Arctic environment. Structural crashworthiness with regard to crushing and fracture is a key element in the strength performance assessment of ship collisions in the Arctic, which provides the primary motivation for the study. This article is a sequel to the authors’ previous paper [1]. In contrast to the previous paper, which dealt with test structures made of American Society for Testing and Materials (ASTM) A500-type carbon steel with the wall slenderness coefficient (b/t) of 37.5, the present paper considers grade A steel with the wall slenderness coefficient (b/t) of 25. Crushing tests are undertaken on square tubes subject to a quasi-static crushing load at both room and low temperatures. The effect of low temperatures on the material properties is examined on the basis of tensile coupon test results. The crushing behavior of the square tubes in this test is compared with LS-DYNA computations. It is found that low temperatures have a significant effect on the crashworthiness of steel-plated structures in terms of mean crushing loads and brittle fracture. The use of grade A steel for ships and offshore structures in an Arctic environment is not relevant. The modeling techniques for the structural crashworthiness analysis presented in this paper are found to be pertinent by comparison with experimental results and nonlinear finite element method computations. It is suggested that the collision-accidental limit state design of ships intended to operate in the Arctic region be carried out by taking the effect of low temperatures into account.
Reports on the topic "Slenderness limits"
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FINITE ELEMENT ANALYSIS ON BEHAVIOR OF HCFHST MIDDLE LONG COLUMNS WITH INNER I-SHAPED CFRP UNDER AXIAL LOAD. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.033.
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In this paper, the behavior of high-strength concrete filled high-strength square steel tube (HCFHST) middle long columns with inner I-shaped CFRP profile under axial load was studied. The finite element analysis models were established by ABAQUS software based on reasonable material constitutive relationship models. The whole process curve of load-deformation was analyzed. In addition, effects of concrete strength, steel yield strength, slenderness ratio, steel ratio and configuration ratio of CFRP on mechanical behavior of middle long columns were studied. On the basis of the parametric analysis, the limit slenderness ratio of middle long columns was obtained. Results show that with the increase of steel yield strength, the bearing capacity increases gradually, but ductility decreases. The higher the concrete strength is, the greater the ultimate bearing capacity is. Effect of steel ratio on the ultimate bearing capacity and ductility is relatively obvious. The ultimate bearing capacity of HCFHST middle long columns with inner I-shaped CFRP profile decreases with the increase of slenderness ratio.
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LOCAL BUCKLING BEHAVIORS OF COLD-FORMED CIRCULAR HOLLOW SECTIONS HIGH STRENGTH STEEL STUB COLUMNS BASED ON A HIGH-FIDELITY NUMERICAL MODEL (ICASS’2022). The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.337.
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This paper establishes a high-fidelity numerical model to systematically investigate the local buckling behaviors of cold-formed circular hollow section (CHS) high-strength steel stub columns. Material nonlinearity and geometric nonlinearity are carefully accounted for in the FE model. Based on the Menegotto-Point model, the material constitutive of cold-formed CHS is calibrated considering the characteristics of the curvature of the stress-strain curve. The mesh is uniformly patterned according to the cross-section of the CHSs steel under compression. Subsequently, parametric studies are carried out to study the local buckling mode, buckling strength and ductility of the cold-formed high-strength CHS. The cross-sectional slenderness limit and local buckling strength of CHSs with material strength more than 500 MPa are proposed.