{"id":9297,"date":"2021-08-15T15:31:00","date_gmt":"2021-08-15T19:31:00","guid":{"rendered":"https:\/\/www.purdue.edu\/freeform\/me323\/?page_id=9297"},"modified":"2022-08-09T13:56:42","modified_gmt":"2022-08-09T17:56:42","slug":"beams-deflections-and-boundary-conditions","status":"publish","type":"page","link":"https:\/\/www.purdue.edu\/freeform\/me323\/animations-and-demonstrations\/beams-deflections-and-boundary-conditions\/","title":{"rendered":"Beam deflections and boundary conditions"},"content":{"rendered":"<p>The integrations needed to determine beam deflections require the enforcement of the appropriate displacement and rotation boundary conditions (BCs). It is important that we be able to recognize these boundary conditions as we work through this analysis and be able to check our work in the end. Shown below are three beam problems and animations showing the influence of the location of the roller support condition on the shape of the beam deflection. Can you recognize how these deflection shapes are related back to the beam BCs?<\/p>\n<p>&nbsp;<\/p>\n<hr \/>\n<p><em><strong>Beam #1<\/strong><\/em><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-9299 aligncenter\" src=\"https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/Untitled-2-7-300x201.jpg\" alt=\"\" width=\"300\" height=\"201\" srcset=\"https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/Untitled-2-7-300x201.jpg 300w, https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/Untitled-2-7.jpg 499w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" style=\"border: 1px solid #000000\" src=\"https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/beam01a.gif\" width=\"329\" height=\"263\" \/><\/p>\n<p>The deflection at B and C is zero, as prescribed by the BCs. There are no constraints on the slopes of the displacements at B and C.<\/p>\n<p>&nbsp;<\/p>\n<hr \/>\n<p><em><strong>Beam #2<\/strong><\/em><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-9301 aligncenter\" src=\"https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/Untitled-2-8-300x202.jpg\" alt=\"\" width=\"300\" height=\"202\" srcset=\"https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/Untitled-2-8-300x202.jpg 300w, https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/Untitled-2-8.jpg 498w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" style=\"border: 1px solid #000000\" src=\"https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/beam03a.gif\" width=\"326\" height=\"261\" \/><\/p>\n<p>The deflection at B and C is zero, as prescribed by the BCs. With the fixed condition at B, the slope at B is also zero. There are no constraints on the slope of the displacement at C.<\/p>\n<p>&nbsp;<\/p>\n<p><em><strong>Beam #3<\/strong><\/em><\/p>\n<div><\/div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-9302 aligncenter\" src=\"https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/Untitled-2-9-300x201.jpg\" alt=\"\" width=\"300\" height=\"201\" srcset=\"https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/Untitled-2-9-300x201.jpg 300w, https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/Untitled-2-9.jpg 499w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" style=\"border: 1px solid #000000\" src=\"https:\/\/www.purdue.edu\/freeform\/me323\/wp-content\/uploads\/sites\/2\/2021\/08\/beam04a.gif\" width=\"333\" height=\"266\" \/><\/p>\n<p>The deflection at B and C is zero, as prescribed by the BCs. With the fixed condition at B, the slope at B is also zero. There are no constraints on the slope of the displacement at C. Note that it is difficult to predict the direction (up or down) of the beam displacements due to the distributed load on the beam.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The integrations needed to determine beam deflections require the enforcement of the appropriate displacement and rotation boundary conditions (BCs). It is important that we be able to recognize these boundary conditions as we work through this analysis and be able to check our work in the end. Shown below are three beam problems and animations &hellip; <a href=\"https:\/\/www.purdue.edu\/freeform\/me323\/animations-and-demonstrations\/beams-deflections-and-boundary-conditions\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Beam deflections and boundary conditions<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":10,"featured_media":0,"parent":5074,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-9297","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.purdue.edu\/freeform\/me323\/wp-json\/wp\/v2\/pages\/9297","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.purdue.edu\/freeform\/me323\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.purdue.edu\/freeform\/me323\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/freeform\/me323\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/freeform\/me323\/wp-json\/wp\/v2\/comments?post=9297"}],"version-history":[{"count":7,"href":"https:\/\/www.purdue.edu\/freeform\/me323\/wp-json\/wp\/v2\/pages\/9297\/revisions"}],"predecessor-version":[{"id":9300,"href":"https:\/\/www.purdue.edu\/freeform\/me323\/wp-json\/wp\/v2\/pages\/9297\/revisions\/9300"}],"up":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/freeform\/me323\/wp-json\/wp\/v2\/pages\/5074"}],"wp:attachment":[{"href":"https:\/\/www.purdue.edu\/freeform\/me323\/wp-json\/wp\/v2\/media?parent=9297"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}