{"id":440119,"date":"2025-08-26T15:20:37","date_gmt":"2025-08-26T15:20:37","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/necking-in-ls-dyna\/"},"modified":"2025-08-26T15:20:37","modified_gmt":"2025-08-26T15:20:37","slug":"necking-in-ls-dyna","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/necking-in-ls-dyna\/","title":{"rendered":"Necking in LS-DYNA"},"content":{"rendered":"<p>&lt;p&gt;Good evening,&lt;\/p&gt;&lt;p&gt;I&#8217;m trying to characterize a polymeric material (POM) with 187 SAMP-1 material model. At the moment, Force-Displacement values from FEM are different from experimental ones. This because the simulations starts necking, and force values go down quicky.&lt;br&gt;At the moment, I can not understand what makes the material necking and how can calibrate this phenomena (in exp. values, force goes down slowly).&lt;br&gt;Can someone help me regarding how to handle with this issue? Thank you in advance.&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-440119","topic","type-topic","status-publish","hentry","topic-tag-ls_dyna-1","topic-tag-polymer"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.10 - aioseo.com -->\n\t<meta name=\"description\" content=\"Good evening,I&#039;m trying to characterize a polymeric material (POM) with 187 SAMP-1 material model. At the moment, Force-Displacement values from FEM are different from experimental ones. This because the simulations starts necking, and force values go down quicky.At the moment, I can not understand what makes the material necking and how can calibrate this phenomena\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/necking-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=\"Necking in LS-DYNA | Ansys Learning Forum\" \/>\n\t\t<meta property=\"og:description\" content=\"Good evening,I&#039;m trying to characterize a polymeric material (POM) with 187 SAMP-1 material model. At the moment, Force-Displacement values from FEM are different from experimental ones. This because the simulations starts necking, and force values go down quicky.At the moment, I can not understand what makes the material necking and how can calibrate this phenomena\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/necking-in-ls-dyna\/\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2025-08-26T15:20:37+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2025-08-26T15:20:37+00:00\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n\t\t<meta name=\"twitter:title\" content=\"Necking in LS-DYNA | Ansys Learning Forum\" \/>\n\t\t<meta name=\"twitter:description\" content=\"Good evening,I&#039;m trying to characterize a polymeric material (POM) with 187 SAMP-1 material model. At the moment, Force-Displacement values from FEM are different from experimental ones. This because the simulations starts necking, and force values go down quicky.At the moment, I can not understand what makes the material necking and how can calibrate this phenomena\" \/>\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\\\/necking-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-tag\\\/polymer\\\/#listItem\",\"name\":\"polymer\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"name\":\"Home\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/polymer\\\/#listItem\",\"position\":3,\"name\":\"polymer\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/polymer\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/necking-in-ls-dyna\\\/#listItem\",\"name\":\"Necking in LS-DYNA\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"name\":\"Topics\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/necking-in-ls-dyna\\\/#listItem\",\"position\":4,\"name\":\"Necking in LS-DYNA\",\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/polymer\\\/#listItem\",\"name\":\"polymer\"}}]},{\"@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\\\/necking-in-ls-dyna\\\/#webpage\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/necking-in-ls-dyna\\\/\",\"name\":\"Necking in LS-DYNA | Ansys Learning Forum\",\"description\":\"Good evening,I'm trying to characterize a polymeric material (POM) with 187 SAMP-1 material model. 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