AXLE HOUSING AND UNITIZE BEARING PACK SET MODALCHARACTERISATION

摘要

In this paper, finite element modelling of Axle Housing and Wheel End set isattempted to represent dynamic behaviour of the set as a whole. Axle Housing and Wheel Endsubsets are modal analysed. FEA models are shown and justified, and validity of the modelsis proved by correlation with experimental results. Different models are studied for modellingthe joint between the Axle Housing and the Wheel End and a model is proposed. Finally, thelimitations 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 toAnsys. Since in modal analysis the mass of the model plays an important role, it is necessaryto work with the whole model. Due to this, several simplifications have been made in thegeometrical model in order to minimise the computational cost. Models analysed are theWheel 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 instrumentedhammer. Output is measured in terms of acceleration by piezoelectric accelerometers fixed tothe structure with magnetic parts. In the case of the Wheel Hub, the modal analysis has alsobeen 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 minimuminterference of the fastening in the lowest vibration mode, rubbers have been placed in thenodes 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 andthe Wheel End by modelling rollers as beam elements with E=210Gpa, and considering thatthere is a torsion coupling between rollers rows with beam elements with E=13.5Gpa. Thismodel is suitable to represent dynamic behaviour of Axle Housing and Wheel End set, hasbeen validated by experimental modal analysis, and correlation error obtained is assumed tobe acceptable. Theoretical analyses have been repeated including experimentally adjusteddamping values, and no differences have been obtained in frequency values.