EFFECT OF GEOMETRICAL IMPERFECTION ON ANALYTICAL BUCKLING STRENGTH OF COLD-FORMED LIPPED CHANNEL STEEL MEMBER UNDER COMPRESSION

Thin waled cold-formed steel member is manufactured by cold-forming a galvanized steel sheet of less than 2.3 mm. It is possible to manufacture a variety of cross-sectional shapes with less expensive manufacturing equipment than the conventional hot rolling process. This thin waled cold-formed steel...

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Veröffentlicht in:	Journal of Structural and Construction Engineering (Transactions of AIJ) 2021, Vol.86(779), pp.157-167
Hauptverfasser:	MITSUI, Kazuya, WATANABE, Akane, KOBASHI, Tomoki, IKARASHI, Kikuo
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Sprache:	eng ; jpn
Schlagworte:	Buckling Cold Cold Formed Member Cold rolling Cold working Cold-formed steel Compression tests Compressive strength Cross-sections Defects Distortional Buckling Effective Width Eigenvalues Galvanized steel Galvanized steels Galvanizing Hot rolling Industrial applications Initial geometric imperfections Local Buckling Metal sheets Modular systems Numerical analysis Post Buckling Strength Thickness ratio Webs
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creator	MITSUI, Kazuya WATANABE, Akane KOBASHI, Tomoki IKARASHI, Kikuo
description	Thin waled cold-formed steel member is manufactured by cold-forming a galvanized steel sheet of less than 2.3 mm. It is possible to manufacture a variety of cross-sectional shapes with less expensive manufacturing equipment than the conventional hot rolling process. This thin waled cold-formed steel member allows for greater customization (different web, flange and lip width) that can cater for many industrial applications of ﬂooring, rooﬁng, or modular building systems. In this thin waled cold-formed steel members, since the width-to-thickness ratio of the plate elements that make up the cross-section is large, local buckling is likely to occur at the plate elements before the maximum strength is reached. In addition, since a unique buckling mode called distortional buckling that includes the collapse of the cross-section is occurred, one of the important research subjects is to analyze the buckling behavior in detail and to establish a quantitative evaluation method of member strength. Numerical analysis by the ﬁnite element method is a useful tool for analyzing the complex buckling behavior of thin waled cold-formed steel members. However, regarding the validity of buckling behavior combined with eigenvalue analysis, there are very few studies that analyzed in detail the effect of changes in initial imperfections on the analysis results, and it is necessary to clarify the application range of the method that introduces the initial imperfections based on the eigenvalue analysis results. In this paper, the effect of initial imperfections in the ﬁnite element analysis on the buckling behavior of cold-formed lipped channel steel member is investigated. Firstly, the buckling behavior and its buckling mode are clariﬁed by stub column tests. Then, the effect of the differences in the shape of the initial imperfections in ﬁnite element analysis is investigated. From the stub column tests, the following are found. 1) In the case of a cross-section that satisﬁes the required lip width and the maximum strength is determined by local buckling, the maximum strength can be evaluated by accumulating the maximum strength of each plate element. On the other hand, in the case of a cross-section that does not satisfy the required lip width, the maximum strength determined by local buckling cannot be evaluated by this method. 2) Based on the DSM, the local bucling and the distorsional buckling strength are evaluated on the safe side. Also, the coupled buckling strength, w
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It is possible to manufacture a variety of cross-sectional shapes with less expensive manufacturing equipment than the conventional hot rolling process. This thin waled cold-formed steel member allows for greater customization (different web, flange and lip width) that can cater for many industrial applications of ﬂooring, rooﬁng, or modular building systems. In this thin waled cold-formed steel members, since the width-to-thickness ratio of the plate elements that make up the cross-section is large, local buckling is likely to occur at the plate elements before the maximum strength is reached. In addition, since a unique buckling mode called distortional buckling that includes the collapse of the cross-section is occurred, one of the important research subjects is to analyze the buckling behavior in detail and to establish a quantitative evaluation method of member strength. Numerical analysis by the ﬁnite element method is a useful tool for analyzing the complex buckling behavior of thin waled cold-formed steel members. However, regarding the validity of buckling behavior combined with eigenvalue analysis, there are very few studies that analyzed in detail the effect of changes in initial imperfections on the analysis results, and it is necessary to clarify the application range of the method that introduces the initial imperfections based on the eigenvalue analysis results. In this paper, the effect of initial imperfections in the ﬁnite element analysis on the buckling behavior of cold-formed lipped channel steel member is investigated. Firstly, the buckling behavior and its buckling mode are clariﬁed by stub column tests. Then, the effect of the differences in the shape of the initial imperfections in ﬁnite element analysis is investigated. From the stub column tests, the following are found. 1) In the case of a cross-section that satisﬁes the required lip width and the maximum strength is determined by local buckling, the maximum strength can be evaluated by accumulating the maximum strength of each plate element. On the other hand, in the case of a cross-section that does not satisfy the required lip width, the maximum strength determined by local buckling cannot be evaluated by this method. 2) Based on the DSM, the local bucling and the distorsional buckling strength are evaluated on the safe side. Also, the coupled buckling strength, which does not directly speciﬁed, can be evaluated on the safe side. 3) In the case of a cross-section that does not satisfy the required lip width, the buckling mode changes due to the initial geometric imperfections. From the numerical analysis results with initial imperfections as parameters, the following are found. 4) The buckling mode determines the maximum strength changes in the cross-section that does not satisfy the required lip width due to the diﬀerence in the shape of the initial imperfections. On the other hand, regardless of the required lip width requirement, the shape of the initial imperfect has a small effect on the maximum strength. 5) Regardless of the conformance of the required lip width condition, the analysis condition that introduces the maximum imperfection obtained from the larger value of the web or ﬂange width-to-thickness ratio and eq. (5.a) into the analysis model based on the ﬁrst-order eigenmode can almost reproduce the maximum yield strength obtained from the short column compression test.</description><identifier>ISSN: 1340-4202</identifier><identifier>EISSN: 1881-8153</identifier><identifier>DOI: 10.3130/aijs.86.157</identifier><language>eng ; jpn</language><publisher>Tokyo: Architectural Institute of Japan</publisher><subject>Buckling ; Cold ; Cold Formed Member ; Cold rolling ; Cold working ; Cold-formed steel ; Compression tests ; Compressive strength ; Cross-sections ; Defects ; Distortional Buckling ; Effective Width ; Eigenvalues ; Galvanized steel ; Galvanized steels ; Galvanizing ; Hot rolling ; Industrial applications ; Initial geometric imperfections ; Local Buckling ; Metal sheets ; Modular systems ; Numerical analysis ; Post Buckling Strength ; Thickness ratio ; Webs</subject><ispartof>Journal of Structural and Construction Engineering (Transactions of AIJ), 2021, Vol.86(779), pp.157-167</ispartof><rights>2021 Architectural Institute of Japan</rights><rights>Copyright Japan Science and Technology Agency 2021</rights><lds50>peer_reviewed</lds50><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c2707-dd34dfa3f4495ab2625efdf5cd96add65e499f2c881131bd4cf26e078233cf6b3</citedby><cites>FETCH-LOGICAL-c2707-dd34dfa3f4495ab2625efdf5cd96add65e499f2c881131bd4cf26e078233cf6b3</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><link.rule.ids>314,776,780,1877,4010,27900,27901,27902</link.rule.ids></links><search><creatorcontrib>MITSUI, Kazuya</creatorcontrib><creatorcontrib>WATANABE, Akane</creatorcontrib><creatorcontrib>KOBASHI, Tomoki</creatorcontrib><creatorcontrib>IKARASHI, Kikuo</creatorcontrib><title>EFFECT OF GEOMETRICAL IMPERFECTION ON ANALYTICAL BUCKLING STRENGTH OF COLD-FORMED LIPPED CHANNEL STEEL MEMBER UNDER COMPRESSION</title><title>Journal of Structural and Construction Engineering (Transactions of AIJ)</title><addtitle>J. Struct. Constr. Eng.</addtitle><description>Thin waled cold-formed steel member is manufactured by cold-forming a galvanized steel sheet of less than 2.3 mm. It is possible to manufacture a variety of cross-sectional shapes with less expensive manufacturing equipment than the conventional hot rolling process. This thin waled cold-formed steel member allows for greater customization (different web, flange and lip width) that can cater for many industrial applications of ﬂooring, rooﬁng, or modular building systems. In this thin waled cold-formed steel members, since the width-to-thickness ratio of the plate elements that make up the cross-section is large, local buckling is likely to occur at the plate elements before the maximum strength is reached. In addition, since a unique buckling mode called distortional buckling that includes the collapse of the cross-section is occurred, one of the important research subjects is to analyze the buckling behavior in detail and to establish a quantitative evaluation method of member strength. Numerical analysis by the ﬁnite element method is a useful tool for analyzing the complex buckling behavior of thin waled cold-formed steel members. However, regarding the validity of buckling behavior combined with eigenvalue analysis, there are very few studies that analyzed in detail the effect of changes in initial imperfections on the analysis results, and it is necessary to clarify the application range of the method that introduces the initial imperfections based on the eigenvalue analysis results. In this paper, the effect of initial imperfections in the ﬁnite element analysis on the buckling behavior of cold-formed lipped channel steel member is investigated. Firstly, the buckling behavior and its buckling mode are clariﬁed by stub column tests. Then, the effect of the differences in the shape of the initial imperfections in ﬁnite element analysis is investigated. From the stub column tests, the following are found. 1) In the case of a cross-section that satisﬁes the required lip width and the maximum strength is determined by local buckling, the maximum strength can be evaluated by accumulating the maximum strength of each plate element. On the other hand, in the case of a cross-section that does not satisfy the required lip width, the maximum strength determined by local buckling cannot be evaluated by this method. 2) Based on the DSM, the local bucling and the distorsional buckling strength are evaluated on the safe side. Also, the coupled buckling strength, which does not directly speciﬁed, can be evaluated on the safe side. 3) In the case of a cross-section that does not satisfy the required lip width, the buckling mode changes due to the initial geometric imperfections. From the numerical analysis results with initial imperfections as parameters, the following are found. 4) The buckling mode determines the maximum strength changes in the cross-section that does not satisfy the required lip width due to the diﬀerence in the shape of the initial imperfections. On the other hand, regardless of the required lip width requirement, the shape of the initial imperfect has a small effect on the maximum strength. 5) Regardless of the conformance of the required lip width condition, the analysis condition that introduces the maximum imperfection obtained from the larger value of the web or ﬂange width-to-thickness ratio and eq. (5.a) into the analysis model based on the ﬁrst-order eigenmode can almost reproduce the maximum yield strength obtained from the short column compression test.</description><subject>Buckling</subject><subject>Cold</subject><subject>Cold Formed Member</subject><subject>Cold rolling</subject><subject>Cold working</subject><subject>Cold-formed steel</subject><subject>Compression tests</subject><subject>Compressive strength</subject><subject>Cross-sections</subject><subject>Defects</subject><subject>Distortional Buckling</subject><subject>Effective Width</subject><subject>Eigenvalues</subject><subject>Galvanized steel</subject><subject>Galvanized steels</subject><subject>Galvanizing</subject><subject>Hot rolling</subject><subject>Industrial applications</subject><subject>Initial geometric imperfections</subject><subject>Local Buckling</subject><subject>Metal sheets</subject><subject>Modular systems</subject><subject>Numerical analysis</subject><subject>Post Buckling Strength</subject><subject>Thickness ratio</subject><subject>Webs</subject><issn>1340-4202</issn><issn>1881-8153</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2021</creationdate><recordtype>article</recordtype><recordid>eNo9kEtPg0AUhYnRxFpd-QdIXBrqvBhgJ6UDJfIKpQtXkynMaEltK7QLV_51B9s0mdx7k_OdezPHMB4hmGCIwYtYt_3EpRNoO1fGCLoutFxo42s9YwIsggC6Ne76vgWAEo_CkfHLwpAFlZmHZsTylFVlHPiJGacFKwchzjNTPz_zk_fqX5oug7ckziJzUZUsi6r54A3yZGaFeZmymZnERaFbMPezjCUaY7qmLJ2y0lxmM12DPC1Ktljo5ffGjRKbXj6c-9hYhqwK5laSR8M5q0YOcKymwaRRAitCPFusEEW2VI2y68ajommoLYnnKVTrH0MMVw2pFaISOC7CuFZ0hcfG02nvvtt9H2V_4O3u2G31SY6IS7XJI1hTzyeq7nZ930nF9936S3Q_HAI-JMyHhLlLuU5Y068nuu0P4kNeWNEd1vVGXljH8c6Wi1R_io7LLf4DJiJ7xw</recordid><startdate>2021</startdate><enddate>2021</enddate><creator>MITSUI, Kazuya</creator><creator>WATANABE, Akane</creator><creator>KOBASHI, Tomoki</creator><creator>IKARASHI, Kikuo</creator><general>Architectural Institute of Japan</general><general>Japan Science and Technology Agency</general><scope>AAYXX</scope><scope>CITATION</scope><scope>8FD</scope><scope>FR3</scope><scope>KR7</scope></search><sort><creationdate>2021</creationdate><title>EFFECT OF GEOMETRICAL IMPERFECTION ON ANALYTICAL BUCKLING STRENGTH OF COLD-FORMED LIPPED CHANNEL STEEL MEMBER UNDER COMPRESSION</title><author>MITSUI, Kazuya ; WATANABE, Akane ; KOBASHI, Tomoki ; IKARASHI, Kikuo</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c2707-dd34dfa3f4495ab2625efdf5cd96add65e499f2c881131bd4cf26e078233cf6b3</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng ; jpn</language><creationdate>2021</creationdate><topic>Buckling</topic><topic>Cold</topic><topic>Cold Formed Member</topic><topic>Cold rolling</topic><topic>Cold working</topic><topic>Cold-formed steel</topic><topic>Compression tests</topic><topic>Compressive strength</topic><topic>Cross-sections</topic><topic>Defects</topic><topic>Distortional Buckling</topic><topic>Effective Width</topic><topic>Eigenvalues</topic><topic>Galvanized steel</topic><topic>Galvanized steels</topic><topic>Galvanizing</topic><topic>Hot rolling</topic><topic>Industrial applications</topic><topic>Initial geometric imperfections</topic><topic>Local Buckling</topic><topic>Metal sheets</topic><topic>Modular systems</topic><topic>Numerical analysis</topic><topic>Post Buckling Strength</topic><topic>Thickness ratio</topic><topic>Webs</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>MITSUI, Kazuya</creatorcontrib><creatorcontrib>WATANABE, Akane</creatorcontrib><creatorcontrib>KOBASHI, Tomoki</creatorcontrib><creatorcontrib>IKARASHI, Kikuo</creatorcontrib><collection>CrossRef</collection><collection>Technology Research Database</collection><collection>Engineering Research Database</collection><collection>Civil Engineering Abstracts</collection><jtitle>Journal of Structural and Construction Engineering (Transactions of AIJ)</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>MITSUI, Kazuya</au><au>WATANABE, Akane</au><au>KOBASHI, Tomoki</au><au>IKARASHI, Kikuo</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>EFFECT OF GEOMETRICAL IMPERFECTION ON ANALYTICAL BUCKLING STRENGTH OF COLD-FORMED LIPPED CHANNEL STEEL MEMBER UNDER COMPRESSION</atitle><jtitle>Journal of Structural and Construction Engineering (Transactions of AIJ)</jtitle><addtitle>J. Struct. Constr. Eng.</addtitle><date>2021</date><risdate>2021</risdate><volume>86</volume><issue>779</issue><spage>157</spage><epage>167</epage><pages>157-167</pages><issn>1340-4202</issn><eissn>1881-8153</eissn><abstract>Thin waled cold-formed steel member is manufactured by cold-forming a galvanized steel sheet of less than 2.3 mm. It is possible to manufacture a variety of cross-sectional shapes with less expensive manufacturing equipment than the conventional hot rolling process. This thin waled cold-formed steel member allows for greater customization (different web, flange and lip width) that can cater for many industrial applications of ﬂooring, rooﬁng, or modular building systems. In this thin waled cold-formed steel members, since the width-to-thickness ratio of the plate elements that make up the cross-section is large, local buckling is likely to occur at the plate elements before the maximum strength is reached. In addition, since a unique buckling mode called distortional buckling that includes the collapse of the cross-section is occurred, one of the important research subjects is to analyze the buckling behavior in detail and to establish a quantitative evaluation method of member strength. Numerical analysis by the ﬁnite element method is a useful tool for analyzing the complex buckling behavior of thin waled cold-formed steel members. However, regarding the validity of buckling behavior combined with eigenvalue analysis, there are very few studies that analyzed in detail the effect of changes in initial imperfections on the analysis results, and it is necessary to clarify the application range of the method that introduces the initial imperfections based on the eigenvalue analysis results. In this paper, the effect of initial imperfections in the ﬁnite element analysis on the buckling behavior of cold-formed lipped channel steel member is investigated. Firstly, the buckling behavior and its buckling mode are clariﬁed by stub column tests. Then, the effect of the differences in the shape of the initial imperfections in ﬁnite element analysis is investigated. From the stub column tests, the following are found. 1) In the case of a cross-section that satisﬁes the required lip width and the maximum strength is determined by local buckling, the maximum strength can be evaluated by accumulating the maximum strength of each plate element. On the other hand, in the case of a cross-section that does not satisfy the required lip width, the maximum strength determined by local buckling cannot be evaluated by this method. 2) Based on the DSM, the local bucling and the distorsional buckling strength are evaluated on the safe side. Also, the coupled buckling strength, which does not directly speciﬁed, can be evaluated on the safe side. 3) In the case of a cross-section that does not satisfy the required lip width, the buckling mode changes due to the initial geometric imperfections. From the numerical analysis results with initial imperfections as parameters, the following are found. 4) The buckling mode determines the maximum strength changes in the cross-section that does not satisfy the required lip width due to the diﬀerence in the shape of the initial imperfections. On the other hand, regardless of the required lip width requirement, the shape of the initial imperfect has a small effect on the maximum strength. 5) Regardless of the conformance of the required lip width condition, the analysis condition that introduces the maximum imperfection obtained from the larger value of the web or ﬂange width-to-thickness ratio and eq. (5.a) into the analysis model based on the ﬁrst-order eigenmode can almost reproduce the maximum yield strength obtained from the short column compression test.</abstract><cop>Tokyo</cop><pub>Architectural Institute of Japan</pub><doi>10.3130/aijs.86.157</doi><tpages>11</tpages><oa>free_for_read</oa></addata></record>
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subjects	Buckling Cold Cold Formed Member Cold rolling Cold working Cold-formed steel Compression tests Compressive strength Cross-sections Defects Distortional Buckling Effective Width Eigenvalues Galvanized steel Galvanized steels Galvanizing Hot rolling Industrial applications Initial geometric imperfections Local Buckling Metal sheets Modular systems Numerical analysis Post Buckling Strength Thickness ratio Webs
title	EFFECT OF GEOMETRICAL IMPERFECTION ON ANALYTICAL BUCKLING STRENGTH OF COLD-FORMED LIPPED CHANNEL STEEL MEMBER UNDER COMPRESSION
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