Modal math may not add up

摘要

There's no question that multiaxial testing can be more realistic than a succession of uniaxial tests. However, hexapods and orthogonal 6DOF machines are more complex and expensive than a traditional single-axis shaker, and so are the controllers. Nevertheless, in the hands of an experienced test engineer, 6DOF testing can disclose vibration modes that are completely missed when testing one axis at a time.