One method for predicting the occurrence of brake noise is complex eigenvalue analysis (CEA). Based on the inheritance property of the CEA method, the results are always overestimated. Is there a new process that can overcome the shortcomings of Complex Eigenvalue Analysis (CEA)?
Can Complex Eigenvalue Analysis (CEA) be improved in any method in order to compensate for its shortcomings?
Are there any methods to change the mathematical formulation to minimize CEA's overprediction?
Gurumoorthy Sp You might want to add some modal damping to reduce the number of potentially unstable modes.
Hello,
I would say, rather than addressing the overestimation to CEA methods, that the problem presents a strong coupling of modeshapes of hard-to-model structures, such as the brake disk, the pads, the caliper and all the suspension brackets. All these parts, plus the boundary conditions, have to be properly described in a complex-valued fashion, which means the material properties, with the actual damping, must be well updated.
In the paper Conference Paper Dynamic Behaviour Characterization of a Brake Disc by Means ...
the operative deflection shapes of the disk alone were already better characterized by complex-valued ODSs.Once you properly add damping of all parts in the problem, it might happen that the complex eigenvalues lower their position in the frequency domain, as well as the amplitudes of motion decrease.
Please have a look at Conference Paper Frequency analysis of a motorbike under motion conditions
to follow the CEA as descriptors of the unstable motion.Or just see how experiment-based rotor-dynamics is influenced by hard-to-model boundary conditions, such as fluid bearings: Conference Paper Experiencing rotor and fluid film bearing dynamics
Just my two cents ;-)
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