{"id":241384,"date":"2022-11-18T20:19:44","date_gmt":"2022-11-18T20:19:44","guid":{"rendered":"\/forum\/forums\/topic\/cylinder-tank-hydrostatic-pressure-problem\/"},"modified":"2022-11-18T20:19:44","modified_gmt":"2022-11-18T20:19:44","slug":"cylinder-tank-hydrostatic-pressure-problem","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/cylinder-tank-hydrostatic-pressure-problem\/","title":{"rendered":"Cylinder tank hydrostatic pressure problem"},"content":{"rendered":"<p>Hello Everyone,<br \/>I&#8217;m modelling a rigid tank with SHELL181 and FLUID30 elements in APDL. The cylinder wall height is 15.65 m, the radius is 7 m.&nbsp;<br \/>I have defined the hydrostatic pressure, with SFGRAD and SF,PRES command.<br \/><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2022\/11\/18-11-2022-1668802577-mceclip0.png\"><br \/>As you can see hydrostatic pressure get correctly along the wall. At the bottom of the wall it is 0.1565 MPa (15.65*10=156.5 kN\/m2).<br \/><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2022\/11\/18-11-2022-1668802638-mceclip1.png\"><br \/>My problem is that the tensile stress with static analysis is 2.5 MPa (2500 kN\/m), but according to pressure vessel formula it is P*R=156.5*7=1095 kN\/m.<br \/>When I delete the pressure, there is no tensile stress in the wall, so just this hydrostatic pressure cause this stress value.<br \/>How is this possible?&nbsp;<\/p>\n","protected":false},"template":"","class_list":["post-241384","topic","type-topic","status-closed","hentry","topic-tag-apdl","topic-tag-hydrostatic","topic-tag-tank-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["268185","18229"],"_bbp_author_ip":["23.44.170.61"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["1434"],"_edit_lock":["1668957796:197496"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["241384"],"_bbp_forum_id":["27791"],"_bbp_engagement":["18229","268185"],"_bbp_voice_count":["2"],"_bbp_reply_count":["2"],"_bbp_last_reply_id":["241722"],"_bbp_last_active_id":["241722"],"_bbp_last_active_time":["2022-11-22 18:15:27"]},"test":"armin-bozsonyikgmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/241384","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\/241384\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=241384"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}