{"id":32504,"date":"2020-08-24T19:02:34","date_gmt":"2020-08-24T19:02:34","guid":{"rendered":"https:\/\/www.simscale.com\/?page_id=32504"},"modified":"2023-09-04T21:00:20","modified_gmt":"2023-09-04T21:00:20","slug":"follower-pressure","status":"publish","type":"page","link":"https:\/\/www.simscale.com\/docs\/validation-cases\/follower-pressure\/","title":{"rendered":"Validation Case: Cantilever Plate Subjected to a Follower Pressure"},"content":{"rendered":"\n\n\n\n<p class=\"wp-block-paragraph\">This validation case belongs to solid mechanics. It uses a cantilever plate geometry to validate the follower pressure boundary condition.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">SimScale results are compared to simulation results, presented in [SSNV145]\\(^1\\). The reference uses Code_Aster to perform the analysis.<\/p>\n\n\n\n<div class=\"hw-block hw-btnWrapper hw-btnWrapper--alignCenter \">\n    <a href=\"https:\/\/www.simscale.com\/workbench\/?pid=8947568796839447788\" class=\"hw-btn    \" rel=\"noopener \" target=\"_blank\"    >\n        View Project    <\/a>\n<\/div>\n\n\n\n\n<h2 id=\"geometry\" class=\"wp-block-heading\" >Geometry<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The geometry for this project consists of a cantilever plate, as seen in Figure 1:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_18-05-03.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"591\" height=\"338\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_18-05-03.jpg\" alt=\"cantilever plate follower pressure validation case\" class=\"wp-image-32653\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_18-05-03.jpg 591w, https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_18-05-03-300x172.jpg 300w\" sizes=\"auto, (max-width: 591px) 100vw, 591px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 1: Cantilever plate geometry. The results will be assessed at point P.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">The dimensions of the geometry are given in Table 1:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td><strong>Coordinates<\/strong><\/td><td><strong>A<\/strong><\/td><td><strong>B<\/strong><\/td><td><strong>C<\/strong><\/td><td><strong>D<\/strong><\/td><td><strong>E<\/strong><\/td><td><strong>F<\/strong><\/td><td><strong>G<\/strong><\/td><td><strong>H<\/strong><\/td><td><strong>P<\/strong><\/td><\/tr><tr><td>x \\([m]\\)<\/td><td>0<\/td><td>0<\/td><td>0<\/td><td>0<\/td><td>10<\/td><td>10<\/td><td>10<\/td><td>10<\/td><td>10<\/td><\/tr><tr><td>y \\([m]\\)<\/td><td>0.5<\/td><td>-0.5<\/td><td>-0.5<\/td><td>0.5<\/td><td>0.5<\/td><td>-0.5<\/td><td>-0.5<\/td><td>0.5<\/td><td>0<\/td><\/tr><tr><td>z \\([m]\\)<\/td><td>-0.05<\/td><td>-0.05<\/td><td>0.05<\/td><td>0.05<\/td><td>-0.05<\/td><td>-0.05<\/td><td>0.05<\/td><td>0.05<\/td><td>0<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">Table 1: Coordinates of points within the cantilever plate geometry<\/figcaption><\/figure>\n\n\n\n<h2 id=\"analysis-type-and-mesh\" class=\"wp-block-heading\" >Analysis Type and Mesh<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Tool Type<\/strong>: <a aria-label=\"undefined (opens in a new tab)\" href=\"https:\/\/www.code-aster.org\/\" target=\"_blank\" rel=\"noreferrer noopener\">Code_Aster<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Analysis Type<\/strong>: Nonlinear <a href=\"https:\/\/www.simscale.com\/docs\/analysis-types\/static\/\">static<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Mesh and Element Types<\/strong>: Two meshes are used in this case. The first one is a second-order mesh created in SimScale with the <a href=\"https:\/\/www.simscale.com\/docs\/simulation-setup\/meshing\/standard\/\">standard algorithm<\/a>. Case B uses a second-order hexahedral mesh. It was created locally and imported to SimScale.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Table 2 contains details of the resulting meshes:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td><strong>Case<\/strong><\/td><td><strong>Mesh Type<\/strong><\/td><td><strong>Nodes<\/strong><\/td><td><strong>Element Type<\/strong><\/td><\/tr><tr><td>A<\/td><td>Second-order standard<\/td><td>9700<\/td><td>Standard<\/td><\/tr><tr><td>B<\/td><td>Second-order hexahedral<\/td><td>3502<\/td><td>Standard<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">Table 2: Characteristics of the meshes used for cases A and B<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 2 shows the standard mesh, used for case A:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_19-33-35.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"445\" height=\"387\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_19-33-35.jpg\" alt=\"second order standard mesh cantilever beam\" class=\"wp-image-32654\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_19-33-35.jpg 445w, https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_19-33-35-300x261.jpg 300w\" sizes=\"auto, (max-width: 445px) 100vw, 445px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 2: Discretization obtained with a second-order standard mesh<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Similarly, Figure 3 shows the second-order hexahedral mesh, that was imported to SimScale.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_19-39-56.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"583\" height=\"426\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_19-39-56.jpg\" alt=\"hexahedral mesh imported to simscale med\" class=\"wp-image-32655\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_19-39-56.jpg 583w, https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_19-39-56-300x219.jpg 300w\" sizes=\"auto, (max-width: 583px) 100vw, 583px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 3: Hexahedral mesh imported to SimScale. It contains a total of 3502 nodes.<\/figcaption><\/figure>\n<\/div>\n\n\n<div class=\"hw-block hw-note hw-note--info hw-note\">\n    <div class=\"hw-note__title\">\n        <p class=\"hw-note__titleText\"><i class=\"fa fa-exclamation-circle\" aria-hidden=\"true\"><\/i>Note<\/p>\n    <\/div>\n    <div class=\"hw-note__body\">\n        <p>Especially for nonlinear analysis, such as this one, we recommend second-order meshes. They provide more accurate results, due to the higher number of nodes.\r\n<br>\r\n<br>\r\nThe following <a href=\"https:\/\/www.simscale.com\/knowledge-base\/which-type-of-finite-element-should-i-use\/\">article<\/a> provides further information on second-order meshes for finite element analysis.<\/p>\n    <\/div>\n<\/div>\n\n\n\n<h2 id=\"simulation-setup\" class=\"wp-block-heading\" >Simulation Setup<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Material<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><em><em>Material behavior<\/em><\/em>: <em>Linear elastic<\/em><\/li>\n\n\n\n<li>\\((E)\\) <em>Young&#8217;s modulus<\/em> = 1.2e+7<em> \\(<\/em>Pa<em>\\)<\/em><\/li>\n\n\n\n<li>\\((\\nu)\\) <em>Poisson&#8217;s ratio<\/em> = 0.3<\/li>\n\n\n\n<li>\\((\\rho)\\) <em>Density<\/em> = 1000 \\(kg\/m\u00b3\\)<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Boundary Conditions<\/strong>:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The boundary conditions will be defined based on Figure 1:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Constraints\n<ul class=\"wp-block-list\">\n<li><em>Fixed support<\/em> on face ABCD<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Surface loads\n<ul class=\"wp-block-list\">\n<li><em>Follower Pressure<\/em> \\(P\\), applied on face CDHG. The following formulation is used:<br>$$P = t \\tag{1}$$<br>Where \\(t\\) is the pseudo-time for the nonlinear analysis. This validation case will run until \\(t\\) = 26.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h2 id=\"result-comparison\" class=\"wp-block-heading\" >Result Comparison<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">SimScale results will be compared against two reference simulations. The first one used Code_Aster, while the remaining one used the SAMCEF software.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The results for both reference simulations are found in [1]. The displacements in the X and Z-directions are evaluated at point P (as seen in Figure 1).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In Figure 4, we compare the results for the displacements in the X-direction against Code_Aster. The reference results were extracted using <a href=\"https:\/\/automeris.io\/WebPlotDigitizer\/\" target=\"_blank\" rel=\"noreferrer noopener\">WebPlotDigitizer<\/a>.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_21-57-46.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"606\" height=\"407\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_21-57-46.jpg\" alt=\"follower pressure validation case displacement results\" class=\"wp-image-32656\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_21-57-46.jpg 606w, https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_21-57-46-300x201.jpg 300w\" sizes=\"auto, (max-width: 606px) 100vw, 606px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 4: Result comparison between SimScale results and the reference simulation for DX<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">A similar comparison was made for the displacements in the Z-direction:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_22-04-26.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"605\" height=\"407\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_22-04-26.jpg\" alt=\"follower pressure validation case displacement results vertical direction\" class=\"wp-image-32657\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_22-04-26.jpg 605w, https:\/\/frontend-assets.simscale.com\/media\/2020\/08\/2020-08-18_22-04-26-300x202.jpg 300w\" sizes=\"auto, (max-width: 605px) 100vw, 605px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 5: Result comparison between SimScale results and the reference simulation for DZ<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Additionally, still using point P as a reference, the displacements obtained with SimScale are compared to the results from the SAMCEF software\\(^1\\). Table 1 contains the displacements in the X-direction:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td><strong>Pseudo-time \\([s]\\)<\/strong><\/td><td><strong>SAMCEF \u2013 DX <strong>\\([m]<\/strong>\\)<\/strong><\/td><td><strong>Case A \u2013 DX \\([m]\\)<\/strong><\/td><td><strong>Error [%]<\/strong><\/td><td><strong>Case B \u2013 DX <strong>\\([m]<\/strong>\\)<\/strong><\/td><td><strong>Error [%]<\/strong><\/td><\/tr><tr><td>11<\/td><td>-7.3664<\/td><td>-7.0953<\/td><td>-3.68<\/td><td>-7.0725<\/td><td>-3.99<\/td><\/tr><tr><td>13<\/td><td>-9.03743<\/td><td>-8.7143<\/td><td>-3.58<\/td><td>-8.6851<\/td><td>-3.90<\/td><\/tr><tr><td>22<\/td><td>-13.5098<\/td><td>-13.2380<\/td><td>-2.01<\/td><td>-13.2049<\/td><td>-2.26<\/td><\/tr><tr><td>26<\/td><td>-14.1513<\/td><td>-13.9797<\/td><td>-1.21<\/td><td>-13.9555<\/td><td>-1.38<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">Table 3: Comparison between SimScale and SAMCEF results, for the displacements in the X-direction<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">A comparison for the displacements in the Z-direction is also presented:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td><strong>Pseudo-time \\([s]\\)<\/strong><\/td><td><strong>SAMCEF \u2013 DZ \\([m]\\)<\/strong><\/td><td><strong>Case A \u2013 DZ \\([m]\\)<\/strong><\/td><td><strong>Error [%]<\/strong><\/td><td><strong>Case B \u2013 DZ \\([m]\\)<\/strong><\/td><td><strong>Error [%]<\/strong><\/td><\/tr><tr><td>11<\/td><td>-8.44920<\/td><td>-8.3929<\/td><td>-0.67<\/td><td>-8.3872<\/td><td>-0.73<\/td><\/tr><tr><td>13<\/td><td>-8.42753<\/td><td>-8.4310<\/td><td>0.04<\/td><td>-8.4299<\/td><td>0.02<\/td><\/tr><tr><td>22<\/td><td>-5.78828<\/td><td>-6.0759<\/td><td>4.97<\/td><td>-6.1057<\/td><td>5.48<\/td><\/tr><tr><td>26<\/td><td>-4.43375<\/td><td>-4.7696<\/td><td>7.57<\/td><td>-4.8079<\/td><td>8.44<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">Table 4: Comparison between SimScale and SAMCEF results, for the displacements in the Z-direction<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The results obtained with SimScale for both directions show a great agreement with the reference simulations.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 6 shows the contours for displacements in the X-direction, for case A. The follower pressure boundary condition is updated after each pseudo time step, based on the current deformed state of the geometry. As a result, the plate gets rolled up:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2023\/09\/follower-pressure.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2023\/09\/follower-pressure.jpg\" alt=\"follower pressure displacement contours\" class=\"wp-image-80305\" style=\"width:568px;height:378px\" width=\"568\" height=\"378\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2023\/09\/follower-pressure.jpg 698w, https:\/\/frontend-assets.simscale.com\/media\/2023\/09\/follower-pressure-300x199.jpg 300w\" sizes=\"auto, (max-width: 568px) 100vw, 568px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 6: Displacement contours in the X-direction for case A. The initial position of the plate is shaded in blue.<\/figcaption><\/figure>\n<\/div>\n\n\n\n<div class='hw-block hw-references hw-references'>\n    <p class='hw-references__title'>References<\/p>\n    <ul class='hw-references__list'>\n\n        <li><cite><a href=\"https:\/\/www.code-aster.org\/V2\/doc\/v14\/fr\/man_v\/v6\/v6.04.145.pdf\" target=\"_blank\">\u201cSSNV145 &#8211; Plaque cantilever en grandes rotations\r\nsoumise \u00e0 une pression suiveuse &#8220;<\/a><\/cite><\/li>\n    <\/ul>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>This validation case belongs to solid mechanics. It uses a cantilever plate geometry to validate the follower pressure...","protected":false},"author":114,"featured_media":0,"parent":17191,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"templates\/template-documentation.php","meta":{"_acf_changed":false,"_crdt_document":"","inline_featured_image":false,"footnotes":""},"class_list":["post-32504","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/pages\/32504","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/users\/114"}],"replies":[{"embeddable":true,"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/comments?post=32504"}],"version-history":[{"count":0,"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/pages\/32504\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/pages\/17191"}],"wp:attachment":[{"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/media?parent=32504"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}