{"id":1054,"date":"2017-06-09T09:08:19","date_gmt":"2017-06-09T09:08:19","guid":{"rendered":"http:\/\/buildsoftsupport.com\/?post_type=ht_kb&#038;p=1054"},"modified":"2024-08-21T09:57:29","modified_gmt":"2024-08-21T09:57:29","slug":"how-to-model-a-compression-only-bar","status":"publish","type":"ht_kb","link":"https:\/\/support.buildsoft.eu\/es\/knowledge-base\/how-to-model-a-compression-only-bar\/","title":{"rendered":"How to model a compression bar"},"content":{"rendered":"<ul>\n<li>Select the bar(s) you want to define as compression bar(s).<\/li>\n<li>Click on <img decoding=\"async\" loading=\"lazy\" class=\"img_inline alignnone size-full wp-image-1056\" src=\"http:\/\/buildsoftsupport.com\/wp-content\/uploads\/2017\/06\/KnopScharnieren.png\" alt=\"\" width=\"34\" height=\"34\" \/>. This will set t he bending moment My\u2019 and Mz\u2019 free.<img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-12588\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/CompressionBar1.png\" alt=\"\" width=\"693\" height=\"552\" \/><\/li>\n<li>Select &#8216;Function&#8217; next to &#8216;Nx&#8217; and click on <img decoding=\"async\" loading=\"lazy\" class=\"img_inline alignnone size-full wp-image-1055\" src=\"http:\/\/buildsoftsupport.com\/wp-content\/uploads\/2017\/06\/KnopFx.png\" alt=\"\" width=\"20\" height=\"19\" \/>.\u00a0<img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-12587\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/CompressionBar2.png\" alt=\"\" width=\"693\" height=\"552\" \/><\/li>\n<li>Compression is negative, tension is positive. So define a function for which applies: if F&lt;0 (= compression) then the bar can resist it (=fixed) and when if F&gt;0 (= tension) the bar can&#8217;t resist is (= free).<br \/>\nBut because &#8216;Free&#8217; is the equivalent of 0kN, it&#8217;s <strong>recommended<\/strong> to enter a <strong>very small value<\/strong>. Calculating with 0kN migth give iteration problems.\u00a0The definition of &#8216;small&#8217; depends on the model. For some models it will be 0,1 kN\/m, for others it will be 1kN\/m. Choose a value and calculate the structure. If it calculates, divide the value for example by 2 and try again. If it doesn&#8217;t calculate, multiply the value by 10 and try again. You&#8217;ll see that after a few attemps, the tensile force in the compression bars will be neglectable in comparison to the compression force.<img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-1963\" style=\"color: initial;\" src=\"http:\/\/buildsoftsupport.com\/wp-content\/uploads\/2017\/06\/CompressionBar.png\" alt=\"\" width=\"743\" height=\"515\" srcset=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/CompressionBar.png 743w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/CompressionBar-300x208.png 300w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/CompressionBar-50x35.png 50w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/CompressionBar-60x42.png 60w, https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/CompressionBar-35x24.png 35w\" sizes=\"(max-width: 743px) 100vw, 743px\" \/><\/li>\n<li>Select the function for the other end of the bar.<br \/>\n<img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-12591\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2017\/06\/CompressionBar4.png\" alt=\"\" width=\"693\" height=\"552\" \/><\/li>\n<\/ul>\n<p>Note: the\u00a0countarpart of a\u00a0compression bar\u00a0is <a href=\"http:\/\/buildsoftsupport.com\/knowledge-base\/how-to-model-a-tension-bar-tie-rod\/\">a tie rod<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Select the bar(s) you want to define as compression bar(s). Click on . This will set t he bending moment My\u2019 and Mz\u2019 free. Select &#8216;Function&#8217; next to &#8216;Nx&#8217; and click on .\u00a0 Compression is negative, tension is positive. So define a function for which applies: if F&lt;0 (= compression)&#8230;<\/p>\n","protected":false},"author":3,"comment_status":"open","ping_status":"closed","template":"","format":"standard","meta":[],"ht-kb-category":[1273],"ht-kb-tag":[],"_links":{"self":[{"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb\/1054"}],"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=1054"}],"version-history":[{"count":2,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb\/1054\/revisions"}],"predecessor-version":[{"id":12597,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb\/1054\/revisions\/12597"}],"wp:attachment":[{"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/media?parent=1054"}],"wp:term":[{"taxonomy":"ht_kb_category","embeddable":true,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb-category?post=1054"},{"taxonomy":"ht_kb_tag","embeddable":true,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/ht-kb-tag?post=1054"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}