{"id":1180,"date":"2017-06-23T08:55:39","date_gmt":"2017-06-23T08:55:39","guid":{"rendered":"http:\/\/buildsoftsupport.com\/?post_type=ht_kb&#038;p=1180"},"modified":"2025-09-08T07:37:44","modified_gmt":"2025-09-08T07:37:44","slug":"what-is-the-global-buckling-factor","status":"publish","type":"ht_kb","link":"https:\/\/support.buildsoft.eu\/es\/knowledge-base\/what-is-the-global-buckling-factor\/","title":{"rendered":"What is the global buckling factor?"},"content":{"rendered":"<p>The global buckling factor <strong><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/> <\/strong>is the factor with which the loads in a load combination should be multiplied to obtain buckling in the structure. It is thus an elastic property of the structure and the applied loads. It does not depend upon a standard, but some standards (like Eurocode 3) make use of this property.<\/p>\n<p style=\"text-align: center;\">critical_load_for_global_buckling<strong> = <img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/><\/strong>* current_loads<strong><br \/>\n<\/strong><\/p>\n<p>The global buckling factor is determined during a second order analysis and can be viewed with <img decoding=\"async\" loading=\"lazy\" class=\"img_inline alignnone size-full wp-image-1209 aligncenter\" src=\"http:\/\/buildsoftsupport.com\/wp-content\/uploads\/2017\/06\/KnopEvenwichtscontrole.png\" alt=\"\" width=\"28\" height=\"29\" \/>.<img decoding=\"async\" loading=\"lazy\" class=\"size-full wp-image-15547 aligncenter\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2025\/08\/VensterEvenwichtscontrole.png\" alt=\"\" width=\"486\" height=\"379\" \/><\/p>\n<p>These values are relevant:<\/p>\n<ul>\n<li><strong><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/><\/strong> &lt;1:\u00a0the current loading is <strong>more<\/strong> than the critical loading, and therefore the structure will fail with the current loads. The load combinations for which this is the case, are shown in red. The <strong>shape of the first buckling mode<\/strong> can be requested with the deformations.<br \/>\nThe displacements are scaled in such a way that a global buckling factor <img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/> = 1 is equivalent to a deformation of 1m. A deformation greater than 1m is an accordance with an overall buckling factor <img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/> &lt;1.<img decoding=\"async\" loading=\"lazy\" class=\"wp-image-1208 size-large\" src=\"http:\/\/buildsoftsupport.com\/wp-content\/uploads\/2017\/06\/VensterGlobaleKnik-1024x612.png\" alt=\"\" width=\"643\" height=\"384\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/VensterGlobaleKnik-1024x612.png 1024w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/VensterGlobaleKnik-300x179.png 300w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/VensterGlobaleKnik-768x459.png 768w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/VensterGlobaleKnik-50x30.png 50w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/VensterGlobaleKnik-60x36.png 60w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/VensterGlobaleKnik-35x21.png 35w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/VensterGlobaleKnik.png 1440w\" sizes=\"(max-width: 643px) 100vw, 643px\" \/><br \/>\nThe shape of the first buckling mode gives away how to solve the issue. We distinguish between global and local problems:<\/p>\n<div class=\"su-table su-table-responsive\">\n<table>\n<tbody>\n<tr>\n<th style=\"width: 50%;text-align: center\">Buckling problem is global<\/th>\n<th style=\"text-align: center\">Buckling problem is local<\/th>\n<\/tr>\n<tr>\n<td>\u00a0<img loading=\"lazy\" class=\"alignnone size-large wp-image-15205\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/GlobaleKnikfactor2a.jpg\" alt=\"\" width=\"643\" height=\"335\" \/><\/td>\n<td><img loading=\"lazy\" class=\"alignnone size-full wp-image-15204\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/GlobaleKnikfactor2b.jpg\" alt=\"\" width=\"1116\" height=\"560\" \/><\/td>\n<\/tr>\n<tr>\n<td>The entire structure moves.<br \/>\nReason: stabilising elements (like tie rods) are missing<\/td>\n<td>Only one, for a few bars in the structure are moving.<br \/>\nReason: cross-section of those bars is unsufficient for buckling. If you&#8217;d do a first order calculation followed by a steel verification, these bars wouldn&#8217;t be sufficient either.<\/p>\n<p>Note: because <img loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#092;&#097;&#108;&#112;&#104;&#097;&#095;&#123;&#099;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px\" \/> is based on the buckling load in and element, and different bars can have different buckling loads, it is not excluded that this is only bar in the model with a problem.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div><\/li>\n<li><strong><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/><\/strong> &gt;1:\u00a0the current loading is <strong>less<\/strong> than the critical loading, and therefore the structure will NOT fail (collapse) as a whole with the current loads. Which doesn&#8217;t mean you&#8217;re excused from the steel check!\u00a0 <img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/> looks at the behaviour of the structure as a whole, while the steel check looks at every member separately.<\/li>\n<li><strong><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/><\/strong> = *: the global buckling factor could not be determined. Because we can&#8217;t make any conclusions, these load combinations will also be shown in red. For example: a simply supported beam loaded with self weight. The self weight will because bending, bending can&#8217;t cause global buckling.<\/li>\n<\/ul>\n<p>The global buckling factor <strong><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/><\/strong>\u00a0is independent of a standerd, but some standards use this property . In particular EN 1993-1-1 \u00a75.2.1 uses the global buckling factor to distinguish the difference between a <strong>sway<\/strong> (sensitive to lateral displacements) and a <strong>non-way<\/strong> (insensitive to lateral displacements) structure.<\/p>\n<ul>\n<li><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/> <span style=\"text-decoration: underline;\">&gt;<\/span>\u00a010 or &#8216;-&#8216;: the structure is non-sway<\/li>\n<li><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/ql-cache\/quicklatex.com-699eec6991505f1f9d7a07321aad8a64_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#97;&#108;&#112;&#104;&#97;&#95;&#123;&#99;&#114;&#125;\" title=\"Rendered by QuickLaTeX.com\" height=\"11\" width=\"23\" style=\"vertical-align: -3px;\"\/> &lt; 10: the structure is sway<\/li>\n<\/ul>\n<p>Depending if it&#8217;s a sway or non-sway structure different assumptions apply during <a href=\"https:\/\/support.buildsoft.eu\/knowledge-base\/how-to-do-the-elastic-analysis-for-steel\/\">the analysis and design<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The global buckling factor is the factor with which the loads in a load combination should be multiplied to obtain buckling in the structure. It is thus an elastic property of the structure and the applied loads. It does not depend upon a standard, but some standards (like Eurocode 3)&#8230;<\/p>\n","protected":false},"author":3,"comment_status":"open","ping_status":"closed","template":"","format":"standard","meta":[],"ht-kb-category":[62],"ht-kb-tag":[598,102,103,104,974,204,203,1158,1159,1049,105,205],"_links":{"self":[{"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb\/1180"}],"collection":[{"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb"}],"about":[{"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/types\/ht_kb"}],"author":[{"embeddable":true,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/comments?post=1180"}],"version-history":[{"count":2,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb\/1180\/revisions"}],"predecessor-version":[{"id":17391,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb\/1180\/revisions\/17391"}],"wp:attachment":[{"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/media?parent=1180"}],"wp:term":[{"taxonomy":"ht_kb_category","embeddable":true,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb-category?post=1180"},{"taxonomy":"ht_kb_tag","embeddable":true,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb-tag?post=1180"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}