{"id":162161,"date":"2023-01-25T07:34:27","date_gmt":"2023-01-25T07:34:27","guid":{"rendered":"\/knowledge\/forums\/topic\/how-is-unbalanced-mass-defined-in-rotordynamics\/"},"modified":"2023-07-31T12:36:30","modified_gmt":"2023-07-31T12:36:30","slug":"how-is-unbalanced-mass-defined-in-rotordynamics","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/how-is-unbalanced-mass-defined-in-rotordynamics\/","title":{"rendered":"How is unbalanced mass defined in rotordynamics?"},"content":{"rendered":"<p>The unbalanced mass is defined by a force, where the force is associated with the mass and eccentricity (distance from point to center or &#8216;rotating radius&#8217; in WB Mechanical terms).  We do it this way because we use a stationary frame of reference, so the geometry must be axisymmetric since it is not actually &#8216;rotating&#8217; in the simulation, but the effect of rotation is accounted for in the gyroscopic damping matrix. In a similar way, the unbalance force must be applied to the center, and based on the real and imaginary components, the effect of the unbalance (via forces) is applied to the system.<\/p>\n","protected":false},"template":"","class_list":["post-162161","topic","type-topic","status-publish","hentry","topic-tag-19-2","topic-tag-mechanical","topic-tag-static","topic-tag-structural-and-thermal","topic-tag-structural-dynamics","topic-tag-structural-mechanics"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.10 - aioseo.com -->\n\t<meta name=\"description\" content=\"The unbalanced mass is defined by a force, where the force is associated with the mass and eccentricity (distance from point to center or &#039;rotating radius&#039; in WB Mechanical terms). We do it this way because we use a stationary frame of reference, so the geometry must be axisymmetric since it is not actually &#039;rotating&#039;\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/how-is-unbalanced-mass-defined-in-rotordynamics\/\" \/>\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 Knowledge | Ansys Innovation Space\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"How is unbalanced mass defined in rotordynamics? | Ansys Knowledge\" \/>\n\t\t<meta property=\"og:description\" content=\"The unbalanced mass is defined by a force, where the force is associated with the mass and eccentricity (distance from point to center or &#039;rotating radius&#039; in WB Mechanical terms). 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