STAR – Operating Deflection Shape

View a Structure’s Motion at a Specific Operating Speed or Frequency


Structural motion caused by external forces, gear chatter, imbalance, loose mounting, and other factors is easily analyzed and animated. By creating Operating Deflection Shapes (ODS), the STAR6 System™ enables you to analyze a structure using frequency domain measurements. In most cases, the ODS analysis is performed on a machine in its normal operating condition. You select the frequencies of interest, optionally animating the results to further understand structural dynamics problems.

Accurate Operating Deflection Shape Analysis

The STAR6 System™ generates scaled operating deflection shapes by using autopower and cross spectra in addition to transmissibility measurements- all with the same instrumentation setup. The result: You get accurate deflection shapes that are scaled to acceleration, velocity, displacement, or g’s. These deflection shapes enable you to compare the amplitude of motion for different shapes-a capability not possible with transmissibility measurements alone.

The STAR6 System™ uses special algorithms to track either peaks or frequencies. You can input a specific frequency at which you want to see the structure’s shape. Or, by placing a band around a peak, you can track the peak frequency in the band. Most machines change speed slightly during operation; without the peak tracking technique, it is nearly impossible to obtain accurate operating deflection shapes for machines that drift in speed by as little as one frequency resolution step.