{"id":394301,"date":"2024-11-19T15:03:25","date_gmt":"2024-11-19T15:03:25","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/"},"modified":"2024-11-19T18:55:25","modified_gmt":"2024-11-19T18:55:25","slug":"no-gravity-effect-with-load_body_z-in-ls-dyna","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/","title":{"rendered":"No gravity effect with *LOAD_BODY_Z in LS Dyna"},"content":{"rendered":"<p>&lt;p&gt;&lt;p&gt;&lt;p&gt;Hi,&lt;\/p&gt;&lt;p&gt;I am working on simulating the impact of a pedestrian human body model with a vehicle. In the simulation, the pedestrian is initially struck by the vehicle, causing the body to rotate around the front end of the vehicle. The vehicle comes to a stop after 200 ms. Following the impact, the pedestrian is expected to fall to the ground due to gravity. However, instead of falling, the pedestrian unexpectedly rises after 200 ms. I applied gravity to the entire model using the *LOAD_BODY_Z keyword, as shown in the code below, the unit is mm-s-ton. In the meanwhile, the energy curve showed suddenly kinetic energy drop at 0.28s, that&#8217;s because of the vehicle was stopped at 0.28s. However the internal energy increased significantly after 0.28s, the head and pelvis velocity increased at the same time as well. Could you suggest how I can ensure the pedestrian falls to the ground as expected? &lt;\/p&gt;&lt;p&gt;$&lt;br&gt;*LOAD_BODY_Z&lt;br&gt;$ &nbsp; &nbsp; LCID &nbsp; &nbsp; &nbsp; &nbsp;SF &nbsp; &nbsp;LCIDDR &nbsp; &nbsp; &nbsp; &nbsp;XC &nbsp; &nbsp; &nbsp; &nbsp;YC &nbsp; &nbsp; &nbsp; &nbsp;ZC &nbsp; &nbsp; &nbsp; CID&lt;br&gt;&nbsp; &nbsp; &nbsp; 1003 &nbsp; &nbsp; &nbsp; 1.0 &nbsp; &nbsp; &nbsp; &nbsp; 0&lt;br&gt;$&lt;\/p&gt;&lt;p&gt;*DEFINE_CURVE&lt;br&gt;$:&lt;br&gt;$: Cross-reference summary for Load-curve 1003&lt;br&gt;$: &#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;&lt;br&gt;$:&lt;br&gt;$: Body load definition &lt;No label&gt;: Base Z acceleration vs time&lt;br&gt;$: X axis : Time &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (Units: Time)&lt;br&gt;$: Y axis : Base Z acceleration &nbsp; &nbsp; &nbsp; &nbsp;(Units: Acceleration)&lt;br&gt;$:&lt;br&gt;$: Usage: Transient analysis&lt;br&gt;$:&lt;br&gt;$HMCURVE &nbsp; &nbsp; 2 &nbsp; &nbsp;2 LoadCurve_1003&lt;br&gt;$ &nbsp; &nbsp; LCID &nbsp; &nbsp; &nbsp;SIDR &nbsp; &nbsp; &nbsp; SFA &nbsp; &nbsp; &nbsp; SFO &nbsp; &nbsp; &nbsp;OFFA &nbsp; &nbsp; &nbsp;OFFO &nbsp; &nbsp;DATTYP &nbsp; &nbsp; LCINT&lt;br&gt;&nbsp; &nbsp; &nbsp; 1003 &nbsp; &nbsp; &nbsp; &nbsp; 0 &nbsp; &nbsp; &nbsp; 1.0 &nbsp; &nbsp; &nbsp; 1.0 &nbsp; &nbsp; &nbsp; 0.0 &nbsp; &nbsp; &nbsp; 0.0 &nbsp; &nbsp; &nbsp; &nbsp; 0 &nbsp; &nbsp; &nbsp; &nbsp; 0&lt;br&gt;$ &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;X &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Y&lt;br&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0.0 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-9806.6504&lt;br&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1.5 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-9806.6504&lt;br&gt;$&lt;\/p&gt;&lt;p&gt;Thanks!&lt;\/p&gt;&lt;\/p&gt;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-394301","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.10 - aioseo.com -->\n\t<meta name=\"description\" content=\"Hi,I am working on simulating the impact of a pedestrian human body model with a vehicle. In the simulation, the pedestrian is initially struck by the vehicle, causing the body to rotate around the front end of the vehicle. The vehicle comes to a stop after 200 ms. Following the impact, the pedestrian is expected\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/\" \/>\n\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 4.9.10\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"Ansys Learning Forum | Ansys Innovation Space\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"No gravity effect with *LOAD_BODY_Z in LS Dyna | Ansys Learning Forum\" \/>\n\t\t<meta property=\"og:description\" content=\"Hi,I am working on simulating the impact of a pedestrian human body model with a vehicle. In the simulation, the pedestrian is initially struck by the vehicle, causing the body to rotate around the front end of the vehicle. The vehicle comes to a stop after 200 ms. Following the impact, the pedestrian is expected\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2024-11-19T15:03:25+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2024-11-19T18:55:25+00:00\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n\t\t<meta name=\"twitter:title\" content=\"No gravity effect with *LOAD_BODY_Z in LS Dyna | Ansys Learning Forum\" \/>\n\t\t<meta name=\"twitter:description\" content=\"Hi,I am working on simulating the impact of a pedestrian human body model with a vehicle. In the simulation, the pedestrian is initially struck by the vehicle, causing the body to rotate around the front end of the vehicle. The vehicle comes to a stop after 200 ms. Following the impact, the pedestrian is expected\" \/>\n\t\t<script type=\"application\/ld+json\" class=\"aioseo-schema\">\n\t\t\t{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/no-gravity-effect-with-load_body_z-in-ls-dyna\\\/#breadcrumblist\",\"itemListElement\":[{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"name\":\"Topics\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"position\":2,\"name\":\"Topics\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/no-gravity-effect-with-load_body_z-in-ls-dyna\\\/#listItem\",\"name\":\"No gravity effect with *LOAD_BODY_Z in LS Dyna\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"name\":\"Home\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/no-gravity-effect-with-load_body_z-in-ls-dyna\\\/#listItem\",\"position\":3,\"name\":\"No gravity effect with *LOAD_BODY_Z in LS Dyna\",\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"name\":\"Topics\"}}]},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#organization\",\"name\":\"Ansys Learning Forum\",\"description\":\"Ansys Innovation Space\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/no-gravity-effect-with-load_body_z-in-ls-dyna\\\/#webpage\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/no-gravity-effect-with-load_body_z-in-ls-dyna\\\/\",\"name\":\"No gravity effect with *LOAD_BODY_Z in LS Dyna | Ansys Learning Forum\",\"description\":\"Hi,I am working on simulating the impact of a pedestrian human body model with a vehicle. In the simulation, the pedestrian is initially struck by the vehicle, causing the body to rotate around the front end of the vehicle. The vehicle comes to a stop after 200 ms. Following the impact, the pedestrian is expected\",\"inLanguage\":\"en-US\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#website\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/no-gravity-effect-with-load_body_z-in-ls-dyna\\\/#breadcrumblist\"},\"datePublished\":\"2024-11-19T15:03:25+00:00\",\"dateModified\":\"2024-11-19T18:55:25+00:00\"},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#website\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/\",\"name\":\"Ansys Learning Forum\",\"description\":\"Ansys Innovation Space\",\"inLanguage\":\"en-US\",\"publisher\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#organization\"}}]}\n\t\t<\/script>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"No gravity effect with *LOAD_BODY_Z in LS Dyna | Ansys Learning Forum","description":"Hi,I am working on simulating the impact of a pedestrian human body model with a vehicle. In the simulation, the pedestrian is initially struck by the vehicle, causing the body to rotate around the front end of the vehicle. The vehicle comes to a stop after 200 ms. Following the impact, the pedestrian is expected","canonical_url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"BreadcrumbList","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/#breadcrumblist","itemListElement":[{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum#listItem","position":1,"name":"Home","item":"https:\/\/innovationspace.ansys.com\/forum","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/topics\/#listItem","name":"Topics"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/topics\/#listItem","position":2,"name":"Topics","item":"https:\/\/innovationspace.ansys.com\/forum\/topics\/","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/#listItem","name":"No gravity effect with *LOAD_BODY_Z in LS Dyna"},"previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum#listItem","name":"Home"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/#listItem","position":3,"name":"No gravity effect with *LOAD_BODY_Z in LS Dyna","previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/topics\/#listItem","name":"Topics"}}]},{"@type":"Organization","@id":"https:\/\/innovationspace.ansys.com\/forum\/#organization","name":"Ansys Learning Forum","description":"Ansys Innovation Space","url":"https:\/\/innovationspace.ansys.com\/forum\/"},{"@type":"WebPage","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/#webpage","url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/","name":"No gravity effect with *LOAD_BODY_Z in LS Dyna | Ansys Learning Forum","description":"Hi,I am working on simulating the impact of a pedestrian human body model with a vehicle. In the simulation, the pedestrian is initially struck by the vehicle, causing the body to rotate around the front end of the vehicle. The vehicle comes to a stop after 200 ms. Following the impact, the pedestrian is expected","inLanguage":"en-US","isPartOf":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/#website"},"breadcrumb":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/#breadcrumblist"},"datePublished":"2024-11-19T15:03:25+00:00","dateModified":"2024-11-19T18:55:25+00:00"},{"@type":"WebSite","@id":"https:\/\/innovationspace.ansys.com\/forum\/#website","url":"https:\/\/innovationspace.ansys.com\/forum\/","name":"Ansys Learning Forum","description":"Ansys Innovation Space","inLanguage":"en-US","publisher":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/#organization"}}]},"og:locale":"en_US","og:site_name":"Ansys Learning Forum | Ansys Innovation Space","og:type":"article","og:title":"No gravity effect with *LOAD_BODY_Z in LS Dyna | Ansys Learning Forum","og:description":"Hi,I am working on simulating the impact of a pedestrian human body model with a vehicle. In the simulation, the pedestrian is initially struck by the vehicle, causing the body to rotate around the front end of the vehicle. The vehicle comes to a stop after 200 ms. Following the impact, the pedestrian is expected","og:url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/","article:published_time":"2024-11-19T15:03:25+00:00","article:modified_time":"2024-11-19T18:55:25+00:00","twitter:card":"summary_large_image","twitter:title":"No gravity effect with *LOAD_BODY_Z in LS Dyna | Ansys Learning Forum","twitter:description":"Hi,I am working on simulating the impact of a pedestrian human body model with a vehicle. In the simulation, the pedestrian is initially struck by the vehicle, causing the body to rotate around the front end of the vehicle. The vehicle comes to a stop after 200 ms. Following the impact, the pedestrian is expected"},"aioseo_meta_data":{"post_id":"394301","title":null,"description":null,"keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":"default","schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"local_seo":null,"limit_modified_date":false,"created":"2025-10-19 09:18:36","updated":"2025-10-19 09:18:36","ai":null,"breadcrumb_settings":null,"seo_analyzer_scan_date":null},"aioseo_breadcrumb":"<div class=\"aioseo-breadcrumbs\"><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/forum\" title=\"Home\">Home<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/forum\/topics\/\" title=\"Topics\">Topics<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\tNo gravity effect with *LOAD_BODY_Z in LS Dyna\n\t\t<\/span><\/div>","aioseo_breadcrumb_json":[{"label":"Home","link":"https:\/\/innovationspace.ansys.com\/forum"},{"label":"Topics","link":"https:\/\/innovationspace.ansys.com\/forum\/topics\/"},{"label":"No gravity effect with *LOAD_BODY_Z in LS Dyna","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-gravity-effect-with-load_body_z-in-ls-dyna\/"}],"acf":[],"custom_fields":[{"0":{"_bbp_author_ip":["141.217.167.170"],"_btv_view_count":["499"],"_bbp_topic_status":["unanswered"],"_edit_last":["292659"],"_bbp_revision_log":["a:2:{i:394302;a:2:{s:6:\"author\";i:292659;s:6:\"reason\";s:0:\"\";}i:394386;a:2:{s:6:\"author\";i:292659;s:6:\"reason\";s:0:\"\";}}"],"_edit_lock":["1732042547:292659"],"_bbp_subscription":["480261","50058","292659"],"_bbp_topic_id":["394301"],"_bbp_forum_id":["27814"],"_bbp_engagement":["50058","292659","480261"],"_bbp_voice_count":["3"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["395035"],"_bbp_last_active_id":["395035"],"_bbp_last_active_time":["2024-11-22 23:57:12"]},"test":"yingtaowayne-edu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/394301","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":2,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/394301\/revisions"}],"predecessor-version":[{"id":394386,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/394301\/revisions\/394386"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=394301"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}