{"id":42812,"date":"2020-04-15T14:25:22","date_gmt":"2020-04-15T14:25:22","guid":{"rendered":"\/forum\/forums\/topic\/hourglass-energy-problems-in-autodyn-explicit-dynamics-in-projectile-impact-simulations\/"},"modified":"2020-04-15T14:25:22","modified_gmt":"2020-04-15T14:25:22","slug":"hourglass-energy-problems-in-autodyn-explicit-dynamics-in-projectile-impact-simulations","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/hourglass-energy-problems-in-autodyn-explicit-dynamics-in-projectile-impact-simulations\/","title":{"rendered":"Hourglass energy problems in AUTODYN Explicit Dynamics in projectile impact simulations"},"content":{"rendered":"<p>Hello everyone!&nbsp;<\/p>\n<p><\/p>\n<p>I&#8217;m doing two simulations in the Explicit Dynamics module. Regarding the solver output, both Momentum Summary and Energy Conservation (energy error=0) are&nbsp;fine. However, there is some Hourglass energy,&nbsp; which exceeds the conventional 5% of the Internal Energy. How can it be solved in these cases?<\/p>\n<p><\/p>\n<p>Projectile impact: erosion on material failure, materials: two different&nbsp;explicit&nbsp;structural steels, but the same erosion criteria (Max Principal &nbsp;Strain=0.3,Max Shear Strain=0.5). Only a 90deg slice is analysed, proper symmetry conditions imposed.&nbsp;<\/p>\n<p><\/p>\n<p>Cylinder impact: erosion on material failure, materials: cylinder- explicit steel (Max Eq Plastic Strain=0.2), disk- explicit AL (Max Eq Plastic Strain=0.4). Only a 90deg slice is analysed, proper symmetry conditions imposed.&nbsp;<\/p>\n<p><\/p>\n<p>&nbsp;EDIT: I reduced the target plate size and then refined the mesh on both features, but it didn&#8217;t resolve the issue<\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"template":"","class_list":["post-42812","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["14992"],"_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":["1"],"_btv_view_count":["1865"],"_bbp_subscription":["249342"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["42812"],"_bbp_forum_id":["27791"],"_bbp_engagement":["22","175158"],"_bbp_voice_count":["2"],"_bbp_reply_count":["4"],"_bbp_last_reply_id":["111993"],"_bbp_last_active_id":["111993"],"_bbp_last_active_time":["2020-04-21 18:04:12"]},"test":"bobsik641"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/42812","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\/42812\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=42812"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}