HoloFringe300K Digital Electronic Holography System

Applications:

Vibrations Analysis: 

The system allows you to identify and characterize vibration modes.  The vibration modes show up as fringes on the turbine blade.  These fringes are dark bands on the image that read like a topographical map showing areas of excitation.  The software supplied with the system allows the operator to peak the amplitudes of the modes and take a snap shot of the mode shape which can be seen below.

Mode shapes of a turbine blade obtained by the holography system

The Modal Assurance Criteria (MAC): 

Correlation of mode shapes can be achieved through the use of the MAC.  MAC is a scalar value between zero and one representing the correlation between two mode shapes.  A MAC value near one indicates a high degree of correlation or consistency between two mode shapes.  In this case, the two mode shapes represent the same motion differing only by a complex modal scaler factor(MSF). The MSF can be used to scale the mode shapes to a common level for subsquent manipulations. This may include differencing the mode shapes to understand the variance or combining the mode shapes to improve the estimate. 

Static Deformation: 

The system can identify deformation to test structure in real time when subjected to a static load.  The results can be used to compare with finite element analysis models.

Thermal Exspansion: 

The system can measures displacements at right angles to the line of sight. The resulting fringes measure thermal expansion or unidirectional strain. Time-lapse recordings can be used to collect data for stress relaxation studies.

For more information about the applications of this system please contact us.