Why would an Operational Deflection Shape (ODS) test be performed?

An Operational Deflection Shape (ODS) test is performed primarily to visualize vibration patterns, which can reveal mode shapes associated with resonance. The ODS provides insight into how a structure behaves in its operational environment, allowing engineers to observe the movement of various points on the machine while it is running under normal operating conditions. This visualization can indicate specific areas where vibrations are more pronounced, which may suggest a need for further investigation into the cause of the vibrations.

While generating animations for records and mathematical modeling can be beneficial for understanding structures and their behaviors, they do not capture the real-time dynamics and operational interactions that an ODS test does. Moreover, while examining changes in machine vibration with speed is also critical for diagnosing equipment performance, the primary purpose of an ODS is to observe and analyze the actual vibrational response during standard operation.