{"id":35412,"date":"2019-05-17T14:11:39","date_gmt":"2019-05-17T14:11:39","guid":{"rendered":"\/forum\/forums\/topic\/wave-absorbing-boundary-conditions\/"},"modified":"2019-05-17T14:11:39","modified_gmt":"2019-05-17T14:11:39","slug":"wave-absorbing-boundary-conditions","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/wave-absorbing-boundary-conditions\/","title":{"rendered":"Wave absorbing boundary conditions"},"content":{"rendered":"<p>Hello everyone,<\/p>\n<p><\/p>\n<p>I know this topic has been posted before, and I&#8217;ve read multiple answers already, however my question is a bit different. So I&#8217;ve been modelling a simple soil layer, in transient structural analysis and testing different ways&nbsp;of applying&nbsp;the fixed boundary condition.&nbsp;<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/3dfd451d-52ac-478f-b261-aa4d00c98b48\/7bfc2f20-e343-41c4-9020-aa5000e70e03_capture-ansys-2.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>As you can see, i have this simple solid, I tried placing the fixed boundary condition in different ways. Mainly, at the bottom, at the bottom and on the sides&nbsp;and just at the sides. And running the animation to see the propagation of the acceleration along the model. However I&#8217;m unable to know exactly what&#8217;s causing the reflection. Is it the free end or the fixed end ? I&#8217;ve read an article somewhere that the transient analysis uses the implicit solver, and therefore the boundary conditions are absorbant ? If you can point me out to a documentation explaining this phenomenon I would be grateful. And if you can suggest the best type of boundaries for this kind of analysis, I would be grateful as well (infinite elements and their application, spring elements, I was also thinking about prolonging my model, and applying some kind of material with very high damping value, not sure if that works).<\/p>\n<p><\/p>\n<p>Thank you in advance.<\/p>\n<p><\/p>\n<p>Regards,<br \/>Nizar<\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"template":"","class_list":["post-35412","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["7584"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0","0"],"_btv_view_count":["532"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["35412"],"_bbp_forum_id":["27792"],"_bbp_engagement":["165309"],"_bbp_voice_count":["1"],"_bbp_reply_count":["0"],"_bbp_last_reply_id":["0"],"_bbp_last_active_id":["35412"],"_bbp_last_active_time":["2019-05-17 14:11:39"]},"test":"nizar"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/35412","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/35412\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=35412"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}