Demonstration of a Unified Approach to the Balancing of Flexible Rotors

A flexible rotor balancing procedure, which incorporates the advantages and eliminates the disadvantages of the modal and influence coefficient procedures, has been developed and implemented. This new procedure, referred to as the Unified Balancing Approach, has been demonstrated on a supercritical power transmission shaft test rig. The test rig was successfully balanced through four flexural critical speeds with a substantial reduction in effort as compared with the effort required in modal and influence coefficient balancing procedures. A brief discussion of the Unified Balancing Approach and its relationship to the modal and influence coefficient methods is presented. A series of tests which were performed to evaluate the effectiveness of various balancing techniques are described. The results of the Unified Balancing Approach tests are presented and discussed. These results confirm the superiority of this balancing procedure for the supercritical shaft test rig in particular and for multiple-mode balancing in general.