Multi-degree-of-freedom impedance fixture for automated frequency response function measurements

Abstract

System and methods for characterizing a response of a structure-under-test to applied excitation forces using a test fixture. The fixture is selectively coupleable to the structure-under-test and is configured to hold the structure-under-test at a known position and in a known orientation relative to the fixture. A plurality of excitation devices and response sensors are coupled to the fixture. Excitation forces applied to the fixture by the excitation devices are conveyed by the fixture to the structure-under-test and each response sensor measures a dynamic response indicative of a response of the structure-under-test and the fixture to the applied excitation force. A controller receives response sensor data and applies a mathematical coordinate transformation to project the forces and moments corresponding to the applied excitation and the measured dynamic responses to a target point of the structure-under-test and to calculate a system response function based at least in part on the projection.