Sensitivity Analysis Of Nature Frequency And Structure Optimization Design For Vibrating Screen

Vibrating screen is an important screen machine, it has been applied in industriesof mining, metallurgy, petroleum, construction etc widely. It does forced vibrationunder the vibration force, it is easy to be damaged that caused by fatigue failure. Inorder to prolong the service life and increase the strength of the vibrating screen, weneed to improve the structure of the vibrating screen. The natural frequency of avibrating screen should be far away from the excitation frequency to prevent theresonance phenomenon. It can avoid increasing amplitude and damaging the vibratingscreen.ANSYS Parametric Design Language (APDL) is employed to construct athree-dimensional finite element modal of vibrating screen. Then the model analysis ismade. Because the vibration mode of the first nature frequency is the main deformationin the side plate，so the changes of the large modal amplitudes are obvious. That is tosay, when the structure of this position has a small change, it can produce greatinfluence to this frequency; and when it is close to the node of vibration mode, thechanges of this part’s influence on the nature frequency are not obvious. So the parts onthe side plate are selected as variables to do sensitivity analysis. The sensitivity analysisto the first natural frequency of the vibrating screen is carried out, the sensitivity factorscan be got and used as design variables;increasing the frist nature frequency is seen asobjective function to do optimization design, it can avoid the blindness of optimizationdesign. After optimization design, the data should be rounded, then the first naturalfrequency increases by5.58%more than the original model. Finally, we have provideda transient dynamic analysis to the vibrating screen, the result shows that the optimizedvibrating screen meets the strength requirement.