{"id":3010,"date":"2015-04-23T10:08:31","date_gmt":"2015-04-23T09:08:31","guid":{"rendered":"http:\/\/www.solidapps.co.uk\/blog\/?p=3010"},"modified":"2015-11-03T15:42:34","modified_gmt":"2015-11-03T15:42:34","slug":"shells-in-solidworks-simulation-2015-part-2-alignment-and-offset","status":"publish","type":"post","link":"https:\/\/www.solidapps.co.uk\/blog\/2015\/04\/shells-in-solidworks-simulation-2015-part-2-alignment-and-offset\/","title":{"rendered":"Shells in SOLIDWORKS Simulation 2015: Part 2 (Alignment and Offset)"},"content":{"rendered":"

In the first part, we went over some SOLIDWORKS Simulation shell basics \u2013 check out the post here<\/a> in case you missed it. This time, we dive a bit deeper into the relevant data that accompanies shells in Simulation.<\/p>\n

Every shell has two sides, which represent the virtual faces separated by the defined shell thickness.\u00a0There is a top side and a bottom side. By\u00a0default, the bottom side<\/strong> of a shell will appear orange<\/strong> when viewing the mesh in the graphics area. That\u2019s the most important thing\u00a0to remember. The thickness you define for the shell will be the \u201cvirtual distance\u201d between the top and bottom faces. It\u2019s a good idea to keep\u00a0shells facing the same way, so naturally in a model where we have some plates stacked on the top plane, it would be logical to have\u00a0the faces whose normal is\u00a0in the +Y\u00a0global direction be designated as\u00a0the top faces.<\/p>\n

Each shell\u2019s default top\/bottom side is based on default shell alignment and it can vary \u2013 it\u2019s important to note that it won\u2019t necessarily match the\u00a0global coordinate system. Think about a complex wavy\u00a0face that\u00a0doesn\u2019t seem to have any obvious\u00a0alignment with the global coordinate system.\u00a0It will still have a top and bottom face, but whether\u00a0the thickness goes in the desired\u00a0direction is up to\u00a0the user. In cases where we are not just using the midsurface (where half the thickness is above and half is below),\u00a0shell offset and alignment become especially important. They will\u00a0affect\u00a0where the virtual thickness of the shell will go based on the\u00a0face selection.<\/p>\n

In SOLIDWORKS Simulation 2015,\u00a0the process of\u00a0previewing this and keeping shells consistent has some nice improvements. Let\u2019s consider\u00a0this example: we create a new study on a model with two thin stacked plates (both solid bodies) in Simulation 2015. There\u2019s a pressure applied to one side of the stack and a fixture on the other.<\/p>\n

\"stacked<\/a><\/p>\n

 <\/p>\n

We decide to use Define shell by selected faces to test how the shells will behave \u2013 defining the appropriate thickness first to avoid confusion.<\/p>\n

\"stack<\/a><\/p>\n

 <\/p>\n

Immediately, we see\u00a0that the \u201ctop\u201d face we\u00a0clicked on (\u201ctop\u201d in the sense that their outward normal points in the +Y global direction) corresponds to the default bottom side\u00a0of the shell thanks to the orange preview coloring. But since the default offset defaults to midsurface, we want to change that. By setting the offset to top,\u00a0we are\u00a0telling the software that we want the face we\u2019ve\u00a0selected to be the\u00a0top\u00a0shell face.<\/p>\n

\"stack<\/a><\/p>\n

 <\/p>\n

Why might we want that? To\u00a0be consistent with the global coordinate system and\u00a0also the rest of the model, for\u00a0instance. Furthermore, we want to define the shell on the same face the pressure load is acting on. We\u00a0can then flip the default shell top\/bottom alignment if\u00a0needed using the \u201cFlip shell top and bottom\u201d option. In this case, this is necessary to have the\u00a0shell thickness going in the proper direction \u2013 the preview makes this easy to visualize.<\/p>\n

\"stack<\/a><\/p>\n

 <\/p>\n

Whether we need to do this or not\u00a0will depend on the aforementioned default top\/bottom shell alignment. In previous versions of the software, we would need to wait until meshing to flip\u00a0any shells that needed it, but\u00a0starting in the 2015 version, we can define this from the very \u201cbirth\u201d of the shell \u2013 and best of all, have that shell\u2019s flip state persist even if we later choose to remesh.\u00a0We then follow the same procedure for the bottom body, except this time we select the bottom face and offset since that is where the fixture is. No need to flip the alignment in this case.<\/p>\n

\"stack<\/a><\/p>\n

 <\/p>\n

Finally, one of the most important steps to verify the shell setup: mesh and render shell thickness in 3D. By doing this and comparing the positioning, alignment, and thickness of our shells, we can\u00a0make sure the definition is correct.<\/p>\n

\"stack<\/a><\/p>\n

 <\/p>\n

Will this series of blog posts become a trilogy like so many\u00a0movies do these days?\u00a0Maybe\u2026 check back often\u00a0so you don\u2019t miss anything good!<\/p>\n

Originally posted by Jay Seaglar in the SOLIDWORKS Tech Blog<\/a><\/p>\n

\"DoubleRedArrow\"<\/a> Find out more on SOLIDWORKS Simulation<\/a>
\n\"DoubleRedArrow\"<\/a> Contact Sales<\/a>
\n\"DoubleRedArrow\"<\/a> Request a Demo<\/a><\/p>\n

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In the first part, we went over some SOLIDWORKS Simulation shell basics \u2013 check out the post here in case you missed it. This time, we dive a bit deeper… <\/p>\n","protected":false},"author":1,"featured_media":3011,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,6],"tags":[25,113],"class_list":["post-3010","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-solidworks","category-solidworks-simulation","tag-solidworks-2","tag-solidworks-simulation"],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/posts\/3010","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/comments?post=3010"}],"version-history":[{"count":5,"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/posts\/3010\/revisions"}],"predecessor-version":[{"id":3696,"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/posts\/3010\/revisions\/3696"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/media\/3011"}],"wp:attachment":[{"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/media?parent=3010"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/categories?post=3010"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.solidapps.co.uk\/blog\/wp-json\/wp\/v2\/tags?post=3010"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}