With the aim at replacing the original steel supporter

modal analysis and its structure optimization of die casting magnesium alloy steering supporter were conducted. The results reveal that

compared to that of original steel supporter

the first six normal mode frequency of the magnesium alloy supporter is increased

and the relative vib-displacement is slightly reduced. However

the elastic modulus of magnesium alloy is remarkably lower than that of steel

so the local rigidity of magnesium alloy up-beam is lower than that of steel structure

which results in its first vibration deformation in corresponding to location larger than the original steel structure. Through optimizing the original magnesium alloy structure and improving the local rigidity of the up-beam

modal behavior of the magnesium alloy steering supporter can reach or partly exceed the original steel structure.