A Modal-Geometrical Selection Criterion for Master Nodes Applied to Engine Components

Usually, both an experimental modal analysis or a numerical modal analysis performed on reduced model present the problem of master nodes selection. A methodology based on the experience is normally used or computationally heavy criterion can be applied. In that paper, the Modal-Geometrical Selection Criterion (MoGeSeC) is applied to a crankshaft, both for an EMA (experimental modal analysis) and for a reduction procedure. Then the results are compared with other literature criteria. As far as the EMA is concerned, the nodes suggested by MoGeSeC and other criteria are used for identification of the component. The connection conditions between components are origin of uncertainty but in that case the comparison is done for each methodology in the same conditions. In that way MoGeSeC proves to be a very quick and accurate method because the nodes it selects depicts very well the dynamic behavior of the components. The proposed criterion is also applied to the component in order to evaluate the reduced inertia and stiffness matrices. Also in that case MoGeSeC provides the analyzer with a good instrument for solving reduction problem, in fact the selected master nodes are useful for depicting the dynamic behavior of each component, reducing the analysis time and improving accuracy.