Abstract: The dynamic performance of bearing support in heavy dynamic balancing machine is directly related to the safety and accuracy of balancing test. For investigating the dynamic behaviors of bearing support, an impact excitation dynamic stiffness test is first planed according to the special structure style of the bearing support with the testing objectives in mind, and eight dynamic stiffness curves are also measured. In the basis of these data, the actual dynamic stiffness states of bearing support are analyzed from the aspects of its configure style, service time and working condition, and find that there are no obvious performance degradation for bearing support in its working frequency range. After this, several resonance frequencies of bearing support are further identified though finding valleys of the limited dynamic stiffness curves. A model updated finite element model is established from these resonance frequencies for assisting to predict the resonance shapes of bearing support. The resonance shapes are reasonably figured out from the modal, dynamic stiffness and static deformation information calculated from the finite element model together with the experimental dynamic stiffness data, and the rationality of the way of dynamic behaviors prediction is also discussed.

Key words: bearing support;dynamic stiffness;impact excitation test;finite element model;model updating technology