Order-Based Modal Analysis: a modal parameter estimation technique for rotating machineries

Rotating machineries are employed today in a wide variety of industrial applications. There are few machines and other mechanicalsystems which do not include rotating components such as wheels, gears, bearings, shafts and seals. Turbines including steam, gas and wind, electrical motors and generators, turbochargers, and internal combustion engines, are just some examples of rotating machines. In the presence of rotating machineries, the so-called orders appear as multiples or fractions of the rotational speed. They can be defined as the proportional constants between the rotational speed and the frequency. The Order Tracking (OT) theory estimates the amplitude and the phase of the orders. It can be stated that during a run-up or run-down test, the measured response is mainly caused by rotational excitation. This is the main reason behind the idea to perform Operational Modal Analysis (OMA) on tracked orders rather than on the overall spectrum. It is assumed that the structure is excited by a rotating mass with increasing frequency. The excitation can be represented by two perpendicular forces of equal amplitude and in quadrature. The method considers the run-up as a multi-sine sweep excitation and combines advanced order tracking techniques with operational modal analysis to identify the modal parameters. The procedure is known as Order-Based Modal Analysis (OBMA).

ISBN:978-84-16046-80-5

Jaar van publicatie:2015

BOF-keylabel:ja

IOF-keylabel:ja

Authors from:Private, Higher Education

Toegankelijkheid:Closed