Natural Frequencies of Damaged Beams - A New Approach
Journal Title: Romanian Journal of Acoustics and Vibration - Year 2012, Vol 9, Issue 2
Abstract
This paper introduces a relation which describes the influence of discontinuities on the dynamic response of prismatic cantilever beams. The relation, providing the natural frequencies of weakaxis bending vibration modes of damaged beams, was contrived by considering the continuous model in a global approach, opposite to researches presented in literature involving mainly models based on two segments linked by a rotational spring and focusing on the local effect of the discontinuity. To demonstrate the validity of the proposed relation, a cantilever beam was analyzed both in undamaged and damaged case, being highlighted the natural frequency changes due discontinuity for various damage scenarios; finally curves representing frequency changes were plotted. Comparing the results obtained by the two approaches, a similarity for the frequency changes of the first bending vibration modes is obvious, while for higher modes the “classical” approach is not able to provide any result due to limitations of the numerical methods. Opposite, the proposed relation is simple to be utilized and offer precise results for all bending vibration modes, fact proved by examples presented at the end of the paper.
Authors and Affiliations
Gilbert GILLICH, Petru MINDA, Zeno-Iosif PRAISACH, Andrea MINDA
Keywords
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