- Stiffness matrix method of structural analysis examples update#
- Stiffness matrix method of structural analysis examples full#
Therefore, in situations where updating of only mass and stiffness matrices using FRFs is required, the use of complex FRFs based updating formulation is not fully justified and would lead to inaccurate updated models.
Stiffness matrix method of structural analysis examples update#
Use of complex FRFs to update mass and stiffness matrices is not theoretically correct as complex FRFs are not only affected by these two matrices but also by the damping matrix. However, the problem with FRF based methods, for updating mass and stiffness matrices, is that these methods are based on use of complex FRFs. Updating using frequency response functions (FRFs) has been one of the widely used approaches for updating, including updating of mass and stiffness matrices. Since in many situations undamped natural frequencies and mode shapes need to be predicted, it has generally been the practice in these situations to seek updating of only mass and stiffness matrix so as to obtain a reliable prediction model. Quite often a structural dynamic finite element model is required to be updated so as to accurately predict the dynamic characteristics like natural frequencies and the mode shapes. Normal response function method for mass and stiffness matrix updating using complex FRFs The fully-populated stiffness matrix demonstrates the coupling between bearing radial, axial, and tilting bearing deflections.« less This proposed stiffness determination method is validated against experiments in the literature and compared to existing analytical models and widely used advanced computational methods.
Stiffness matrix method of structural analysis examples full#
A numerical method is developed to determine the full bearing stiffness matrix corresponding tomore » two radial, one axial, and two angular coordinates the rotation about the shaft axis is free by design. This model captures the time-dependent characteristics of the bearing contact due to the orbital motion of the rolling elements. A combined surface integral and finite element method is used to solve for the contact mechanics between the rolling elements and races. In this study, a finite element/contact mechanics model is developed for rolling element bearings with the focus of obtaining accurate bearing stiffness for a wide range of bearing types and parameters. Rolling Element Bearing Stiffness Matrix Determination (Presentation)Ĭurrent theoretical bearing models differ in their stiffness estimates because of different model assumptions.