NSMS Fundamentals

• Overview
• Externally Mounted Senors
• Various Measurement Capabilities
• Event Time Determination
• Arrival Times to Deflection Conversion
• Deflection to Stress Conversion
• Complete System Characterization
• Flexible Test Scheduling
• Synchronous Realtime Analysis
• Non-Synchronous Realtime Analysis
• High Cycle Fatigue

Deflection to Stress Conversion

The deflection measurement is a peak-to-peak measurement derived from the axial and tangential deflections of the rotor blade. The shape of the modes in interest, as well as the probe's axial position on the blade (leading edge, mid blade, trailing edge) determine the sensitivity the NSMS system will have to a particular mode. If sensitivity to many modes, or complex modes, is desired, multiple groups of probes placed at different axial locations are utilized. This allows not only for greater mode sensitivity, but will confirm the validity of actual mode shape models. Once all necessary deflections are measured. Stress/Deflection ratios From FE models can be input to calculate corrosponding stress levels.

Example Finite Element Model (FEM)