{"id":2119,"date":"2017-12-22T10:45:11","date_gmt":"2017-12-22T10:45:11","guid":{"rendered":"http:\/\/buildsoftsupport.com\/?post_type=ht_kb&#038;p=2119"},"modified":"2026-08-12T08:50:03","modified_gmt":"2026-08-12T08:50:03","slug":"the-cross-section-of-some-elements-is-insufficient","status":"publish","type":"ht_kb","link":"https:\/\/support.buildsoft.eu\/fr\/knowledge-base\/the-cross-section-of-some-elements-is-insufficient\/","title":{"rendered":"About the skulls"},"content":{"rendered":"<p>After the reinforcement calculation <img decoding=\"async\" loading=\"lazy\" class=\"img_inline alignnone size-full wp-image-3859\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2019\/01\/ButtonReinforcement.jpg\" alt=\"\" width=\"23\" height=\"23\" \/>, you get the following message:<\/p>\n<p style=\"text-align: center;\"><em><img decoding=\"async\" loading=\"lazy\" class=\"size-full wp-image-4695 aligncenter\" src=\"http:\/\/buildsoftsupport.com\/wp-content\/uploads\/2017\/12\/CrossSectionInsufficient.png\" alt=\"\" width=\"290\" height=\"132\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/CrossSectionInsufficient.png 290w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/CrossSectionInsufficient-50x23.png 50w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/CrossSectionInsufficient-60x27.png 60w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/CrossSectionInsufficient-35x16.png 35w\" sizes=\"(max-width: 290px) 100vw, 290px\" \/><\/em><\/p>\n<p><em>[FR]: La section de quelques \u00e9l\u00e9ments est insuffisante.<\/em><br \/>\n<em>[ES]: La secci\u00f3n de algunos elementos es insufieciente.<\/em><\/p>\n<h2>How to handle the skulls<\/h2>\n<h3>What causes the skulls?<\/h3>\n<ul>\n<li>This message is given when the theoretical reinforcement calculated by Diamonds, is more than the maximum allowed reinforcement percentage<sup><a id=\"ref1\" href=\"#fn1\">1<\/a><\/sup> (usually 4% of the concrete section) imposed by the selected concrete standard.<\/li>\n<li>Click &lsquo;OK&rsquo; to close the error.<\/li>\n<li>A skull will be shown in (the centre of gravity of) each element with a problem.<br \/>\n<table>\n<tbody>\n<tr>\n<th style=\"width: 50%;\">Example: skull in a line element<\/th>\n<th>Example: skull in a surface element<\/th>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" loading=\"lazy\" class=\"size-full wp-image-2120 aligncenter\" src=\"http:\/\/buildsoftsupport.com\/wp-content\/uploads\/2017\/12\/Skull.png\" alt=\"\" width=\"732\" height=\"170\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull.png 732w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull-300x70.png 300w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull-50x12.png 50w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull-60x14.png 60w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull-35x8.png 35w\" sizes=\"(max-width: 732px) 100vw, 732px\" \/><\/td>\n<td><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-8735\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull2.png\" alt=\"\" width=\"1021\" height=\"715\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull2.png 1021w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull2-300x210.png 300w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull2-768x538.png 768w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull2-50x35.png 50w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull2-60x42.png 60w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull2-35x25.png 35w\" sizes=\"(max-width: 1021px) 100vw, 1021px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The position of the skull is thus not representative for the position of the problem. It is always drawn at the centre of gravity of the element.<br \/>\nAlthough you can see where the problem lies in a surface element: in the white zones, the reinforcement could not be calculated. More on this later in this article.<br \/>\n<img decoding=\"async\" loading=\"lazy\" class=\"aligncenter wp-image-8736\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull3.png\" alt=\"\" width=\"500\" height=\"442\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull3.png 893w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull3-300x265.png 300w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull3-768x679.png 768w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull3-50x44.png 50w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull3-60x53.png 60w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull3-35x31.png 35w\" sizes=\"(max-width: 500px) 100vw, 500px\" \/><\/li>\n<li>While looking at a reinforcement result, double click an element to see the cause of the problem.<img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-2131 aligncenter\" src=\"http:\/\/buildsoftsupport.com\/wp-content\/uploads\/2017\/12\/SkullCause-1024x690.png\" alt=\"\" width=\"643\" height=\"433\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/SkullCause-1024x690.png 1024w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/SkullCause-300x202.png 300w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/SkullCause-768x517.png 768w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/SkullCause-50x34.png 50w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/SkullCause-60x40.png 60w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/SkullCause-35x24.png 35w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/SkullCause.png 1075w\" sizes=\"(max-width: 643px) 100vw, 643px\" \/><br \/>\nPossible causes are:<\/p>\n<ul>\n<li>ULS (Ultimate Limit State)<br \/>\nToo much reinforcement required to take axial force N and\/or bending moment M in ULS.<\/li>\n<li>SLS (Service Limit State)<br \/>\nToo much reinforcement required to limit the concrete and steel stresses based on the internal forces in SLS.<\/li>\n<li>Shear and\/or torsion<br \/>\nToo much reinforcement required to take the shear V and\/or torsional force Mx in ULS.<\/li>\n<li>Buckling<br \/>\nToo much reinforcement required to meet the requirements for buckling according to EN 1992-1-1 \u00a75.8.8.<br \/>\nDiamonds uses the method based on nominal curvature to calculate second order effects. However, this method has a limited range of use. If an element is too slender, it requires non-linear analyis and the method implemented in Diamonds can no longer be used. In that case Diamonds will also show a skull and the caption will say &lsquo;buckling&rsquo;.<\/li>\n<li>Fire<br \/>\nThe additional reinforcmeent to meet a certain fire resistance results in the maximum allowed reinforcement percentage to be exceeded.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>Solution<\/h2>\n    \t\t<div class=\"hts-messages hts-messages--alert    \" id=\"\" style=\"\">\r\n    \t\t\t    \t\t\t    \t\t\t\t<p>\r\n    \t\t\t\t\tThe &lsquo;solutions&rsquo; in the table below only make sense when the geometry, boundary conditions and loads are defined properly.<\/p>\n<ul>\n<li>If you&rsquo;ve applied a load twice by accident, no function in Diamonds will be able to detect that.<\/li>\n<li>If you didn&rsquo;t apply the correct <a href=\"https:\/\/support.buildsoft.eu\/knowledge-base\/how-to-define-the-correct-beam-plate-interaction\/\" target=\"_blank\" rel=\"noopener\">beam-plate interactions<\/a>, no function in Diamonds will tell you that.<\/li>\n<li>If you accidently adjusted the floor height by playing with the level manager, no function in Diamonds will tell you that.<\/li>\n<li>If you accidently entered the wrong dimensions of the concrete element, no function in Diamonds will tell you that.<\/li>\n<li>&#8230;<\/li>\n<\/ul>\n<p>So before you start with the solutions below, verify the geometry and loads. Additionally: it&rsquo;s a good habit to know what you&rsquo;re calculating and what you expect as a result. It will help you detect error and understand the results. For example: what bending moment do I expect in beam X? And what longitudinal reinforcement corresponds to this? Does that amount of reinforcement exceeds the maximum allowed reinforcement percentage?     \t\t\t\t<\/p>\r\n    \t\t\t    \t\t\t\r\n    \t\t<\/div><!-- \/.ht-shortcodes-messages -->\r\n    \t\t\n<table>\n<tbody>\n<tr>\n<th><\/th>\n<th>skull in a line element<\/th>\n<th>skull in a surface element<\/th>\n<\/tr>\n<tr>\n<td>ULS or SLS<\/td>\n<td>Increase section, choose better concrete quality.<\/p>\n<p>In case of columns, try <a href=\"https:\/\/support.buildsoft.eu\/knowledge-base\/what-is-the-difference-between-the-reinforcement-patterns-and-why-is-one-more-economic-than-another\/\" target=\"_blank\" rel=\"noopener\">an identical or proportional distribution pattern for the reinforcement<\/a>. If that doesn&rsquo;t help, maybe you need more columns?<\/td>\n<td>Determine if the skull is a peak-related problem or a field related problem (more info below).<\/td>\n<\/tr>\n<tr>\n<td>Shear and\/or torsion<\/td>\n<td>Check if the correct internal boundary conditions between <a href=\"https:\/\/support.buildsoft.eu\/knowledge-base\/how-to-define-the-correct-beam-plate-interaction\/\" target=\"_blank\" rel=\"noopener noreferrer\">beams and plates <\/a>are defined.<br \/>\nIf so, and the element is not sufficiant: increase section, choose better concrete quality<\/td>\n<td>Diamonds doesn&rsquo;t verify shear\/ torsion in surface elements<\/td>\n<\/tr>\n<tr>\n<td>Buckling<\/td>\n<td>\n<ul>\n<li>When a beam and plate are poured together, the beam is often placed eccentric. The eccentricity will cause axial forces (compression) in the beam. Since Diamonds doesn&rsquo;t know they will be poured together, and that the beam can&rsquo;t buckle, he&rsquo;ll perform a buckling check on it, causing high reinforcement. To turn off the buckling check for this type of beam, select the beam, click on <img decoding=\"async\" loading=\"lazy\" class=\"img_inline alignnone size-large wp-image-2122\" src=\"http:\/\/buildsoftsupport.com\/wp-content\/uploads\/2017\/12\/KnopKnikParameters.png\" alt=\"\" width=\"37\" height=\"36\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/KnopKnikParameters.png 37w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/KnopKnikParameters-35x35.png 35w\" sizes=\"(max-width: 37px) 100vw, 37px\" \/>in the geometry configuration <img decoding=\"async\" loading=\"lazy\" class=\"img_inline alignnone size-full wp-image-2121\" src=\"http:\/\/buildsoftsupport.com\/wp-content\/uploads\/2017\/12\/GeometryConfiguration.png\" alt=\"\" width=\"22\" height=\"26\" \/>. Unselect the boxes before the buckling lengths.<\/li>\n<li>In case of a column:\n<ul>\n<li>check if buckling length is well defined.<\/li>\n<li>Try <a href=\"https:\/\/support.buildsoft.eu\/knowledge-base\/what-is-the-difference-between-the-reinforcement-patterns-and-why-is-one-more-economic-than-another\/\" target=\"_blank\" rel=\"noopener\">an identical or proportional distribution pattern<\/a>.<\/li>\n<li>Increase section, choose better concrete quality, add more columns.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/td>\n<td>Diamonds doesn&rsquo;t verify buckling in surface elements<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Note: sometimes it is interesting to know the results behind the skull (to see how much exceedance there is) or to even hide the skull (if the skulls result from peaks). Read <a href=\"http:\/\/buildsoftsupport.com\/knowledge-base\/how-to-show-the-reinforcement-results-behind-a-skull\/\">here <\/a>how to do so.<\/p>\n<h3>Peak-related versus a field related problem in surface-elements<\/h3>\n<p>In order to judge how to deal with skulls in surface elements, you need to know the cause of the skull. Or by extension: where are the white zones located? In a peak-sensitive area or in the middle of the plate?<\/p>\n<table>\n<tbody>\n<tr>\n<th style=\"width: 50%;\">Peak related<\/th>\n<th>Field related<\/th>\n<\/tr>\n<tr>\n<td>If the skull is peak related, the white zone has <strong>a radius of one mesh triangle<\/strong>.<br \/>\n<img decoding=\"async\" loading=\"lazy\" class=\"size-large wp-image-8738 aligncenter\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull6.png\" alt=\"\" width=\"597\" height=\"543\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull6.png 597w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull6-300x273.png 300w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull6-50x45.png 50w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull6-60x55.png 60w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull6-35x32.png 35w\" sizes=\"(max-width: 597px) 100vw, 597px\" \/><\/td>\n<td>If the skull is field related, the white zone has a radius of <strong>more than one mesh triangle.<\/strong><br \/>\n<img decoding=\"async\" loading=\"lazy\" class=\"size-full wp-image-8737 aligncenter\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull7.png\" alt=\"\" width=\"592\" height=\"536\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull7.png 592w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull7-300x272.png 300w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull7-50x45.png 50w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull7-60x54.png 60w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull7-35x32.png 35w\" sizes=\"(max-width: 592px) 100vw, 592px\" \/><\/td>\n<\/tr>\n<tr>\n<td>There are a few typical places where peak results intend to occur:<\/p>\n<ul>\n<li>Above point supports<\/li>\n<li>Where a line support suddenly ends<\/li>\n<li>Inner corners<\/li>\n<\/ul>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-8739\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull8-1024x239.png\" alt=\"\" width=\"643\" height=\"150\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull8-1024x239.png 1024w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull8-300x70.png 300w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull8-768x179.png 768w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull8-50x12.png 50w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull8-60x14.png 60w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull8-35x8.png 35w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/12\/Skull8.png 1133w\" sizes=\"(max-width: 643px) 100vw, 643px\" \/><\/p>\n<p><a href=\"https:\/\/support.buildsoft.eu\/knowledge-base\/how-to-handle-peaks\" target=\"_blank\" rel=\"noopener noreferrer\">This article<\/a> gives more information on what peaks are, how they arise and how to handle them.<\/td>\n<td>When a surface-elements contains a field-related skull, the only solution is to increase the cross-section or choose a better concrete quality.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><sup id=\"fn1\">1. The maximum allowed reinforcement percentage can be consulted in Diamonds via the menu <em>Edit &gt; Material library<\/em> &gt; * Find the relevant concrete quality in the list * &gt; select the relevant standard &gt; go to the tab page <em>Advanced<\/em>.\u00a0\u00bb href=\u00a0\u00bb#ref1&Prime;&gt;\u21a9<\/sup><\/p>\n","protected":false},"excerpt":{"rendered":"<p>After the reinforcement calculation , you get the following message: [FR]: La section de quelques \u00e9l\u00e9ments est insuffisante. [ES]: La secci\u00f3n de algunos elementos es insufieciente. How to handle the skulls What causes the skulls? This message is given when the theoretical reinforcement calculated by Diamonds, is more than the&#8230;<\/p>\n","protected":false},"author":3,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":[],"ht-kb-category":[68],"ht-kb-tag":[263,429,1034,1035,428,426,1200,427,129,1036,920,1348,613,615,614,425,123,1107,1033,1032],"_links":{"self":[{"href":"https:\/\/support.buildsoft.eu\/fr\/wp-json\/wp\/v2\/ht-kb\/2119"}],"collection":[{"href":"https:\/\/support.buildsoft.eu\/fr\/wp-json\/wp\/v2\/ht-kb"}],"about":[{"href":"https:\/\/support.buildsoft.eu\/fr\/wp-json\/wp\/v2\/types\/ht_kb"}],"author":[{"embeddable":true,"href":"https:\/\/support.buildsoft.eu\/fr\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/support.buildsoft.eu\/fr\/wp-json\/wp\/v2\/comments?post=2119"}],"version-history":[{"count":3,"href":"https:\/\/support.buildsoft.eu\/fr\/wp-json\/wp\/v2\/ht-kb\/2119\/revisions"}],"predecessor-version":[{"id":30949,"href":"https:\/\/support.buildsoft.eu\/fr\/wp-json\/wp\/v2\/ht-kb\/2119\/revisions\/30949"}],"wp:attachment":[{"href":"https:\/\/support.buildsoft.eu\/fr\/wp-json\/wp\/v2\/media?parent=2119"}],"wp:term":[{"taxonomy":"ht_kb_category","embeddable":true,"href":"https:\/\/support.buildsoft.eu\/fr\/wp-json\/wp\/v2\/ht-kb-category?post=2119"},{"taxonomy":"ht_kb_tag","embeddable":true,"href":"https:\/\/support.buildsoft.eu\/fr\/wp-json\/wp\/v2\/ht-kb-tag?post=2119"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}