Ground vibration testing (GVT) and Resonance Assessment Profile (RAP) testing are modal test techniques specifically focused on aircraft and spacecraft. The natural frequencies, mode shapes and damping ratios obtained from these tests provide critical information for flight safety assessments including flutter and structural dynamics.
Ground vibration testing (GVT) measures the dynamic response characteristics of an airframe using multiple shakers and accelerometers with multiple input multiple output (MIMO) signal processing and analysis.
Resonance assessment profile (RAP) testing measures the dynamic response characteristics of a component, or system such as a control surface, sensor or external stores using a modal hammer to excite vibration of the test article.
GVT also aids engineers in determining the modal characteristics for an entire airplane, and it is usually done late in the development phase.
Applications for GVT and RAP testing include new airframe designs and modifications to established designs of fixed wing aircraft, rotorcraft, and spacecraft.
Measuring the natural frequencies and mode shapes of rotating turbine blade (bucket) rows.
Determine the natural frequencies and mode shapes of a rotor train as it twists about the axis of rotation.
Identify the root cause of noise and vibration problems in aerospace or industrial machinery via ODS, spectral, order tracking or joint time frequency analysis.