Abstract
Keywords - Unitize Bearing, Torsion Coupling, Modal Analysis, Finite Element Model, Correlation
Abstract - In this paper, finite element modelling of Axle Housing and Wheel End set is attempted to represent dynamic behaviour of the set as a whole. Axle Housing and Wheel End subsets are modal analysed. FEA models are shown and justified, and validity of the models is proved by correlation with experimental results. Different models are studied for modelling the joint between the Axle Housing and the Wheel End and a model is proposed. Finally, the limitations of the approached model are pointed out.
Theoretical Modal Analysis: Ansys has been used as the solver to run FEA modal analysis. Geometrical models are developed through Pro Engineer and are exported as IGES files to Ansys. Since in modal analysis the mass of the model plays an important role, it is necessary to work with the whole model. Due to this, several simplifications have been made in the geometrical model in order to minimise the computational cost. Models analysed are the Wheel Hub, the Axle Housing and Bearing Pack set, and the Axle Housing and Wheel End (Wheel Hub and Bearing Pack).
Experimental Modal Analysis: The systems are excited by impact with an instrumented hammer. Output is measured in terms of acceleration by piezoelectric accelerometers fixed to the structure with magnetic parts. In the case of the Wheel Hub, the modal analysis has also been performed with a laser vibro-meter, which measures the response in terms of velocity. All components were held up by elastic rubber bands. In order to assure minimum interference of the fastening in the lowest vibration mode, rubbers have been placed in the nodes of the mode and perpendicular to the direction of vibration.
A finite element model has been proposed to simulate the joint between the Axle Housing and the Wheel End by modelling rollers as beam elements with E=210Gpa, and considering that there is a torsion coupling between rollers rows with beam elements with E=13.5Gpa. This model is suitable to represent dynamic behaviour of Axle Housing and Wheel End set, has been validated by experimental modal analysis, and correlation error obtained is assumed to be acceptable. Theoretical analyses have been repeated including experimentally adjusted damping values, and no differences have been obtained in frequency values.