{"id":402979,"date":"2024-12-30T19:04:47","date_gmt":"2024-12-30T19:04:47","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/errors-with-multi-connected-bodies-using-aqwa-3\/"},"modified":"2024-12-30T19:27:47","modified_gmt":"2024-12-30T19:27:47","slug":"errors-with-multi-connected-bodies-using-aqwa-3","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/errors-with-multi-connected-bodies-using-aqwa-3\/","title":{"rendered":"Errors with multi-connected bodies using AQWA"},"content":{"rendered":"

<p>I am working on modeling a Split Hopper Barge in ANSYS for my thesis project and am encountering several issues. Below is a detailed description of my setup and the problems I am facing:<\/p><\/p>\n

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  1. <p>Model Setup:<\/strong><\/p>\n
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    • I have created two joints on the deck: one hinge joint and one universal joint. This setup was intended to avoid redundancy. The gap between the two hulls is 180 mm, as shown in the attached diagram.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

      <p>\"ThisTo simulate the hydraulic cylinder, I used two cables with initial tension placed below each joint. The initial tension in the cables was determined based on static force calculations.\"\"At the bottom, I modeled two fenders (forward and aft), as shown in the diagrams.\"\"<\/p><p>2. Simulation Results:<\/strong><\/p><\/p>\n

        <li style=”list-style-type: none;”><\/p>\n
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        • Diffraction Analysis:<\/strong> The diffraction analysis ran successfully without any issues.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

          <p>Response Analysis:<\/strong><\/p><\/p>\n

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          • During the stability analysis, the bodies are moving randomly, going above and below the water level unexpectedly.<\/li>\n<\/ul>\n

            <p>The lateral forces at the hinges are excessively high, reaching values as large as <span class=”katex”><span class=”base”><span class=”mord”>1<\/span><span class=”mord”>0^<span class=”mord mtight”>11<\/span><\/span><span class=”mord”>kN<\/span><\/span><\/span>. These forces should ideally be around 900 kN, as per static calculations<\/p><p>\"\"<\/p><p>The time response analysis fails to run.\"\"<\/p><p> <\/p><p>When attempting a simplified setup with a single hinge joint at the center of the vessel, the stability analysis does not converge.<\/p><p>\"\"<\/p><p> <\/p><p>Using a fixed joint at the center also results in unrealistically high lateral forces, which are not physically accurate.<\/p><p> <\/p><p>\"\" .<\/p><p> <\/p><p>Request for Help:<\/strong><br>I need this model for my thesis project and am looking for guidance on resolving these issues. Specifically:<\/p><\/p>\n

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            • Why are the bodies moving randomly in the stability analysis, and how can I resolve this?<\/li>\n
            • What could be causing the excessively high lateral forces in the hinges?<\/li>\n
            • Are there any specific changes to the joint setup or modeling approach that could improve convergence and stability?<\/li>\n<\/ul>\n

              <p>I would greatly appreciate any insights or recommendations from the community. Thank you!<\/p><\/p>\n","protected":false},"template":"","class_list":["post-402979","topic","type-topic","status-publish","hentry","topic-tag-aqwa","topic-tag-hydrodynamic-response"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["402979"],"_bbp_subscription":["498104","180344"],"_bbp_author_ip":["103.158.43.18"],"_bbp_last_reply_id":["404461"],"_bbp_last_active_id":["404461"],"_bbp_last_active_time":["2025-01-10 15:27:51"],"_bbp_reply_count":["7"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["498104","180344"],"_btv_view_count":["546"],"_bbp_topic_status":["unanswered"],"_edit_last":["498104"],"_bbp_revision_log":["a:1:{i:402982;a:2:{s:6:\"author\";i:498104;s:6:\"reason\";s:11:\"in complete\";}}"],"_bbp_notification_enabled":["498104"],"_edit_lock":["1735587053:498104"]},"test":"oe23m012smail-iitm-ac-in"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/402979","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":1,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/402979\/revisions"}],"predecessor-version":[{"id":402982,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/402979\/revisions\/402982"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=402979"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}