Learning Forum

[GloriaGloria]

Hi;nI want to analyze a shaft system for coupled axial and torsional vibration. I know the masses and inertias as well as stiffness and damping coefficients. I understood how the model system for torsional vibration but the thing I couldn't understand is how can I define 2 combine 14 (one is for torsional and one is for axial) to one line?n

[Ashish Khemka]

nnMaybe an example like the one below may be of help to you:nnnRegards,nAshish Khemkan

[GloriaGloria]

Thanks for help but unfortunatly I can not see them sample. I understood that I can create to Combine 14 element between two nodes but I can not see coupled vibration effect. Torsional and axial direction so not effect each other n

[BenjaminStarling]

nAre you working in Mechanical?nIn Mechanical, you can define two line bodies that are overlapping, but not sharing geometry. Use a command snippet to turn each line body into their respective springs, and then merge the nodes. A single combin14 element can either be a 3 dimensional longitudinal spring, or act in a single dimension. It cannot act in two dimensions, hence why you need two line bodies.nThe other option is to use the bushing element, COMBI250, but this is only available in later releases. Or you can use the bushing joint.nn