Vibration analysis of heavy machine gearbox housing using Finite Element Method

In this paper the influence of various properties of materials on the natural frequencies and vibration mode shapes in a differential casing for the heavy car is studied. Mechanical properties play an important role in determining the output frequencies and vibrational deformations. For this purpose, the differential model was designed in software CATIA and entered in simulation software ABAQUS which has the high ability to estimate the dynamic behavior of different systems. Materials such as gray cast iron with high vibration damping, steel with high density and rigidity, aluminum and magnesium alloys with low density were evaluated for the differential casing. The results showed that the natural frequency of the first five vibrational modes differ in the materials and by choosing gray cast iron can prevent a resonance phenomenon. Another part of the numerical simulation is dedicated to the effect of connection type between two parts of differential on the dynamic behavior. For this purpose, one of the screws for connecting the two parts of the differential was not secure, a defect that may be caused by an operator when repairs. For one bolt loosened condition natural frequency decreases about 3 to 4 percent. This can increase the chance of a resonance effect.