Abstract

For implementing force limiting during a shaker vibration test it is often necessary to add adaptive fixturing above the force transducers as an interface to the test article mount points. Since the measured force contribution due to this added mass influences the force-limited input notching, the standard recommended practice is to limit adaptive fixturing mass to 10% of the total mass above the force transducers to minimize the notching error. However, it is sometimes difficult to design interface fixturing that can meet that mass-limiting criterion while maintaining the requisite rigidity to avoid dynamic influence of the fixturing. This paper develops a quantification of the notching error due to adaptive fixturing mass, along with nominal force sensitivity and mass measurement error, and recommends approaches for reducing or otherwise evaluating the effect of this error to aid in fixturing design that may exceed the 10% mass criterion.