Learning Forum

[mohammedlaminemekhalfia]

Dear allnnI am trying to perform modal analysis on a twisted Beam Just to know the natural frequencies.nfor the simulation what I did is to import the piece assign fixed geometries apply material used and meshing than run simulation.nI would like to see if my results are analytically near to the simulation so I would like please to have someone help me in with a simplified formulas to calculate the 3 first mode nI used a formulas for uniform canteliver beam to compare it gives a near value (8% error) for the 1st mode but not for the others since the error is huge ( 2nd and 3rd modes)nI used this formulas since a lot of article mention that the analytical calculation remain the same for uniform and non uniform beamn

[Ashish Khemka]

nnYou should not expect such a discrepancy between Ansys results and analytical calculations. The following two links indicate a comparison between hand calculation and analysis results and the difference is < 1%:nnnhttps://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v201/en/wb_vm/wbvt_VM-WB-MECH-003.htmlnnFor a cantilever natural frequency please refer to the following article:nnnnHope this helps.nnRegards,nAshish Khemkan===============nnTo access Ansys Help: https://forum.ansys.com/discussion/3978/how-to-access-the-ansys-online-help