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Lili Xie - One of the best experts on this subject based on the ideXlab platform.
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the ductility based Strength Reduction Factor for the mainshock aftershock sequence type ground motions
Bulletin of Earthquake Engineering, 2015Co-Authors: Changhai Zhai, Weiping Wen, Lili XieAbstract:This manuscript investigates the Strength Reduction Factor of single degree of freedom system with constant ductility performance subjected to the mainshock–aftershock sequence-type ground motions. The recorded and artificial sequence-type ground motions are used. The aftershock ground motions in sequence are scaled to have different relative intensity levels. Four hysteretic models are used to simulate the different type of structures. The effects of period, ductility Factor, site condition, aftershock, hysteretic behavior and damping are studied statistically. The results indicate that the strong aftershock ground motion has more obvious influences on Strength Reduction Factors in short period region than on those in long period region. The degrading behavior would decrease the Strength Reduction Factor of structure with short period at a magnitude of <20 %, while it would increase that of structure with medium-long period at a maximum level of 20 %. Finally, a predictive model, incorporating the effect of aftershock, is proposed to determine the Strength Reduction Factor in the seismic design.
Ben Young - One of the best experts on this subject based on the ideXlab platform.
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design of cold formed stainless steel lipped channel sections with web openings subjected to web crippling under end one flange loading condition
Advances in Structural Engineering, 2017Co-Authors: Amir M Yousefi, Ying Lian, Asraf Uzzaman, James B.p. Lim, Charles G Clifton, Ben YoungAbstract:This article presents a numerical investigation on the web crippling Strength of cold-formed stainless steel lipped channel sections with circular web openings under end-one-flange loading condition. In order to take into account the influence of the circular web openings, a parametric study involving 1992 finite element analyses was performed, covering duplex EN1.4462, austenitic EN1.4404 and ferritic EN1.4003 stainless steel grades; from the results of the parametric study, Strength Reduction Factor equations are proposed. The web crippling Strengths predicted by the Reduction Factor equations are first compared to the Strengths calculated using the equations recently proposed for cold-formed carbon steel lipped channel sections. It is demonstrated that the Strength Reduction Factor equations proposed for cold-formed carbon steel are unconservative for the stainless steel grades by up to 7%. Unified Strength Reduction Factor equations are then proposed that can be applied to all three stainless steel gr...
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Web crippling behaviour of cold-formed steel channel sections with web holes subjected to interior-one-flange loading condition – Part II: parametric study and proposed design equations
Thin-walled Structures, 2017Co-Authors: Ying Lian, Asraf Uzzaman, James B.p. Lim, Gasser Abdelal, David Nash, Ben YoungAbstract:A parametric study of cold-formed steel sections with web openings subjected to web crippling under interior-one-flange (IOF) loading condition is undertaken, using finite element analysis, to investigate the effects of web holes and cross-sections sizes. The holes are located either centred beneath the bearing plate or with a horizontal clear distance to the near edge of the bearing plate. It was demonstrated that the main Factors influencing the web crippling Strength are the ratio of the hole depth to the depth of the web, the ratio of the length of bearing plate to the flat depth of the web and the location of the holes as defined by the distance of the hole from the edge of the bearing plate divided by the flat depth of the web. In this study, design recommendations in the form of web crippling Strength Reduction Factor equations are proposed, which are conservative when compare with both the experimental and finite element results.
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effect of web holes on web crippling Strength of cold formed steel channel sections under end one flange loading condition part ii parametric study and proposed design equations
Thin-walled Structures, 2016Co-Authors: Ying Lian, Asraf Uzzaman, James B.p. Lim, Gasser Abdelal, David Nash, Ben YoungAbstract:This paper reports the second part of a study on the web crippling Strength of cold-formed steel channel sections with web holes under the end-one-flange (EOF) loading condition. A parametric study is presented, using validated finite element models from the companion paper, that investigates the effect of web hole and cross-section sizes. The holes are located either centred above the bearing plates or with a horizontal clear distance to the near edge of the bearing plates. It was demonstrated that the main Factors influencing the web crippling Strength are the ratio of the hole depth to the depth of the web, the ratio of the length of bearing plates to the flat depth of the web and the location of the holes as defined by the distance of the hole from the edge of the bearing plate divided by the flat depth of web. In this study, design recommendations in the form of web crippling Strength Reduction Factor equations are proposed, which are conservative when compared with the experimental and finite element results.
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web crippling Strength of cold formed stainless steel lipped channel sections with web openings subjected to interior one flange loading condition
Steel and Composite Structures, 2016Co-Authors: Amir M Yousefi, Ying Lian, Asraf Uzzaman, James B.p. Lim, Charles G Clifton, Ben YoungAbstract:In cold-formed stainless steel lipped channel-sections, web openings are becoming increasingly popular. Such openings, however, result in the sections becoming more susceptible to web crippling, especially under concentrated loads applied near the web opening. This paper presents the results of a finite element parametric study into the effect of circular web openings on the web crippling Strength of cold-formed stainless steel lipped channelsections for the interior-one-flange (IOF) loading condition. This involves a bearing load applied to the top flange of a length of member, away from the end supports. The cases of web openings located centred beneath the bearing load (i.e. beneath the bearing plate delivering the load) and offset to the bearing plate, are considered. Three grades of stainless steel are considered: duplex EN1.4462, austenitic EN1.4404 and ferretic EN1.4003. In total, 2218 finite element models were analyzed. From the results of the parametric study, Strength Reduction Factors for load bearing capacity are determined, where these Reduction Factors are applied to the bearing capacity calculated for a web without openings, to take account the influence of the web openings. The Strength Reduction Factors are first compared to equations recently proposed for cold-formed carbon steel lipped channel-sections. It is shown that for the case of the duplex grade, the Strength Reduction Factor equations for cold-formed carbon steel are conservative but only by 2%. However, for the cases of the austentic and ferritic grades, the cold-formed carbon steel equations are around 9% conservative. New Strength Reduction Factor equations are proposed for all three stainless steel grades.
James B.p. Lim - One of the best experts on this subject based on the ideXlab platform.
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cold formed ferritic stainless steel unlipped channels with web openings subjected to web crippling under interior two flange loading condition part ii parametric study and design equations
Thin-walled Structures, 2017Co-Authors: Amir M Yousefi, James B.p. Lim, Charles G CliftonAbstract:Abstract A parametric study of unlipped cold-formed ferritic stainless steel sections with circular web openings subjected to web crippling under interior-two-flange (ITF) loading condition is undertaken, using quasi-static finite element analysis, to investigate the effects of web openings and cross-sections sizes. The circular web openings are located either centred or offset to the bearing plates. The Strengths obtained from Reduction Factor equations are first compared to Strengths calculated from equations recently proposed for cold-formed stainless steel lipped channel-sections. It is demonstrated that the Strength Reduction Factor equations previously proposed for cold-formed stainless steel lipped channel-sections can be unconservative for cold-formed ferritic stainless steel unlipped channel-sections by up to 10%. Design recommendations in the form of web crippling Strength Reduction Factor equations are proposed, which are conservative when compared to the both experimental and finite element results.
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design of cold formed stainless steel lipped channel sections with web openings subjected to web crippling under end one flange loading condition
Advances in Structural Engineering, 2017Co-Authors: Amir M Yousefi, Ying Lian, Asraf Uzzaman, James B.p. Lim, Charles G Clifton, Ben YoungAbstract:This article presents a numerical investigation on the web crippling Strength of cold-formed stainless steel lipped channel sections with circular web openings under end-one-flange loading condition. In order to take into account the influence of the circular web openings, a parametric study involving 1992 finite element analyses was performed, covering duplex EN1.4462, austenitic EN1.4404 and ferritic EN1.4003 stainless steel grades; from the results of the parametric study, Strength Reduction Factor equations are proposed. The web crippling Strengths predicted by the Reduction Factor equations are first compared to the Strengths calculated using the equations recently proposed for cold-formed carbon steel lipped channel sections. It is demonstrated that the Strength Reduction Factor equations proposed for cold-formed carbon steel are unconservative for the stainless steel grades by up to 7%. Unified Strength Reduction Factor equations are then proposed that can be applied to all three stainless steel gr...
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Web crippling behaviour of cold-formed steel channel sections with web holes subjected to interior-one-flange loading condition – Part II: parametric study and proposed design equations
Thin-walled Structures, 2017Co-Authors: Ying Lian, Asraf Uzzaman, James B.p. Lim, Gasser Abdelal, David Nash, Ben YoungAbstract:A parametric study of cold-formed steel sections with web openings subjected to web crippling under interior-one-flange (IOF) loading condition is undertaken, using finite element analysis, to investigate the effects of web holes and cross-sections sizes. The holes are located either centred beneath the bearing plate or with a horizontal clear distance to the near edge of the bearing plate. It was demonstrated that the main Factors influencing the web crippling Strength are the ratio of the hole depth to the depth of the web, the ratio of the length of bearing plate to the flat depth of the web and the location of the holes as defined by the distance of the hole from the edge of the bearing plate divided by the flat depth of the web. In this study, design recommendations in the form of web crippling Strength Reduction Factor equations are proposed, which are conservative when compare with both the experimental and finite element results.
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effect of web holes on web crippling Strength of cold formed steel channel sections under end one flange loading condition part ii parametric study and proposed design equations
Thin-walled Structures, 2016Co-Authors: Ying Lian, Asraf Uzzaman, James B.p. Lim, Gasser Abdelal, David Nash, Ben YoungAbstract:This paper reports the second part of a study on the web crippling Strength of cold-formed steel channel sections with web holes under the end-one-flange (EOF) loading condition. A parametric study is presented, using validated finite element models from the companion paper, that investigates the effect of web hole and cross-section sizes. The holes are located either centred above the bearing plates or with a horizontal clear distance to the near edge of the bearing plates. It was demonstrated that the main Factors influencing the web crippling Strength are the ratio of the hole depth to the depth of the web, the ratio of the length of bearing plates to the flat depth of the web and the location of the holes as defined by the distance of the hole from the edge of the bearing plate divided by the flat depth of web. In this study, design recommendations in the form of web crippling Strength Reduction Factor equations are proposed, which are conservative when compared with the experimental and finite element results.
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web crippling Strength of cold formed stainless steel lipped channel sections with web openings subjected to interior one flange loading condition
Steel and Composite Structures, 2016Co-Authors: Amir M Yousefi, Ying Lian, Asraf Uzzaman, James B.p. Lim, Charles G Clifton, Ben YoungAbstract:In cold-formed stainless steel lipped channel-sections, web openings are becoming increasingly popular. Such openings, however, result in the sections becoming more susceptible to web crippling, especially under concentrated loads applied near the web opening. This paper presents the results of a finite element parametric study into the effect of circular web openings on the web crippling Strength of cold-formed stainless steel lipped channelsections for the interior-one-flange (IOF) loading condition. This involves a bearing load applied to the top flange of a length of member, away from the end supports. The cases of web openings located centred beneath the bearing load (i.e. beneath the bearing plate delivering the load) and offset to the bearing plate, are considered. Three grades of stainless steel are considered: duplex EN1.4462, austenitic EN1.4404 and ferretic EN1.4003. In total, 2218 finite element models were analyzed. From the results of the parametric study, Strength Reduction Factors for load bearing capacity are determined, where these Reduction Factors are applied to the bearing capacity calculated for a web without openings, to take account the influence of the web openings. The Strength Reduction Factors are first compared to equations recently proposed for cold-formed carbon steel lipped channel-sections. It is shown that for the case of the duplex grade, the Strength Reduction Factor equations for cold-formed carbon steel are conservative but only by 2%. However, for the cases of the austentic and ferritic grades, the cold-formed carbon steel equations are around 9% conservative. New Strength Reduction Factor equations are proposed for all three stainless steel grades.
Masanobu Sato - One of the best experts on this subject based on the ideXlab platform.
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analytical study on fatigue Strength Reduction Factor of small diameter socket welded pipe joints
Journal of Pressure Vessel Technology-transactions of The Asme, 1998Co-Authors: Makoto Higuchi, Kunihiro Iida, Akira Nakagawa, Takayoshi Yamauchi, Masahiro Saito, Masaaki Hayashi, Masanobu SatoAbstract:Four-point bending and rotating bending fatigue tests were conducted on socket-welded joints made of carbon, stainless, and Cr-Mo steels for clarification of the effects of diameter, welding pass sequence and post-weld heat treatment (PWHT) on fatigue Strength. The results were evaluated quantitatively. Fatigue Strength of socket-welded joints was found to strongly depend on weld pass sequences in fillet welds, this being possibly due to large change in residual stress distribution at roots and toes. The effects of residual stress were thus examined quantitatively by comparison of fatigue Strength of PWHT stress-free specimens with that of as-welded specimens. By the modified Goodman’s method, the lowest S-N curve corresponding to maximum tensile residual stress and the highest S-N curve corresponding to maximum compression residual stress were obtained for different steels and diameters. Conventional S-N data of socket-welded joints were situated between these two limiting curves. Based on the lowest curve, fatigue Strength Reduction Factors of socket-welded joints were proposed.
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a study on fatigue Strength Reduction Factor for small diameter socket welded pipe joints
1996Co-Authors: Makoto Higuchi, Kunihiro Iida, Akira Nakagawa, Makoto Hayashi, Takayoshi Yamauchi, Masahiro Saito, Fukuhisa Matsuda, Masanobu SatoAbstract:Factors that may exert influence on the fatigue Strength of small diameter socket welded joints of nominal diameter in the 20--50 mm range have been investigated by the fully reversed four-point bending fatigue test with the material, diameter, pipe schedule, throat depth, bead shape, slip-on gap, and root defect as the testing parameters. The fatigue Strength of socket joints depended acutely on the diameter. When the diameter is large, the fatigue Strength tended to be low and the fracture is of the root-failure mode; when it is small, on the other hand, the fatigue Strength is high and the fracture is of the toe-failure mode. Stainless steel proved to be superior to carbon steel; it gave rise to 1.37 times the fatigue Strength of the latter for socket joints of nominal diameter 50 mm; the fatigue Strength Reduction Factor determined at 10{sup 7} cycles with respect to the fatigue Strength of smooth base metal in the fully reversed fatigue was about 4 for stainless steel and about 5 for carbon steel. The fatigue Strength was higher, the larger the Sche number (i.e., the thicker the pipe wall); it was improved markedly by placing one final refinement pass on the toemore » or by eliminating the slip-on gap. An empirical formula relating the size of the root defect to the fatigue Strength Reduction has been proposed.« less
Chatpan Chintanapakdee - One of the best experts on this subject based on the ideXlab platform.
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inelastic deformation ratios for design and evaluation of structures single degree of freedom bilinear systems
Journal of Structural Engineering-asce, 2004Co-Authors: Anil K Chopra, Chatpan ChintanapakdeeAbstract:The relationship between the peak deformations of inelastic and corresponding linear single-degree-of-freedom (SDF) systems is investigated. Presented are the median of the inelastic deformation ratio for 214 ground motions organized into 11 ensembles of ground motions, representing large or small earthquake magnitude and distance, and National Earthquake Hazards Reduction Program (NEHRP) site classes B, C, and D; near-fault ground motions are also included. Two sets of results are presented for bilinear nondegrading systems over the complete range of elastic vibration period, Tn: Cμ for systems with known ductility Factor, μ, and CR for systems with known yield-Strength Reduction Factor, Ry. The influence of postyield stiffness on the inelastic deformation ratios Cμ and CR is investigated comprehensively. All data are interpreted in the context of acceleration-sensitive, velocity-sensitive, and displacement-sensitive regions of the spectrum for broad applications. The median Cμ versus Tn and CR versus Tn...