{"id":162228,"date":"2023-01-25T07:34:41","date_gmt":"2023-01-25T07:34:41","guid":{"rendered":"\/knowledge\/forums\/topic\/how-to-perform-modal-analysis-for-a-structure-with-hyperelastic-properties-in-mechanical\/"},"modified":"2023-07-31T12:36:37","modified_gmt":"2023-07-31T12:36:37","slug":"how-to-perform-modal-analysis-for-a-structure-with-hyperelastic-properties-in-mechanical","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/how-to-perform-modal-analysis-for-a-structure-with-hyperelastic-properties-in-mechanical\/","title":{"rendered":"How to perform modal analysis for a structure with hyperelastic properties in Mechanical?"},"content":{"rendered":"

A stand-alone modal analysis in Mechanical would not like to see a nonlinear material. One workaround is to take the workflow of a pre-stressed modal analysis where you apply all your supports\/boundary conditions in the static structural module but apply no loads. Mechanical would not proceed without any loads so simply add a blank command snippet only to trick it into running. This way the stiffness matrix is calculated based on the tangent stiffness at the static level and this stiffness matrix is used for modal calculations. Since there are no loads applied at the static level the results are same as stand-alone modal analysis. It is recommended to check the stresses developed in the structure at the completion of static analysis. There must be zero-stresses in the structure, however if there are any contacts with small penetrations due to coarse mesh, it may generate some non-zero stresses which can influence the modal analysis.<\/p>\n","protected":false},"template":"","class_list":["post-162228","topic","type-topic","status-publish","hentry","topic-tag-4422","topic-tag-mechanical","topic-tag-modal-harmonic-response","topic-tag-structural-dynamics","topic-tag-structural-mechanics"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t