Numerical-experimental comparison of a parametric test-rig for it crossing and veering phenomena

The present paper focuses on a deep investigation of crossing and veering phenomena in a specific mechanical structure. A deep analysis of the state of the art has been developed to highlight the key features of crossing and veering of frequencies during parametric changes of a structure. The analysed structure is an improvement of an existing test-rig, developed to have a system parameter that can be piloted for getting crossing and veering, to purposely couple the bending modes of the orthogonal planes. Both numerical simulations, from a simple 1-dimensional elements model to a full second-order tetrahedral model, and experimental tests were used to evaluate the presence of crossing and veering and to investigate and correlate the corresponding indexes. A good correlation was evidenced and the mode-shapes variation in the crossing and veering zones was presented and discussed by means of a derived index of the modal assurance criterion for parametric analyses. (C) 2019 Elsevier Ltd. All rights reserved.