Publications Details
Development of the force envelope for an acceleration/force extremal controlled vibration test
A method is presented for determining the force spectral density function for a vibration test where a combination of force and acceleration is used for control. First the acceleration spectral density is established based on an envelope of the interface motion between the test item and the mounting structure (the base) in the use (field) environment. The driving point accelerance (acceleration/force) of the test item is measured at the mounting interface. The force required to drive the test item in an acceleration controlled test is then estimated. A force spectral density is then established using the estimated motion controlled force, and a derived force reduction factor. An extremal control vibration test is then performed based on which parameter (input force or input acceleration) reaches based on which parameter (input force or input acceleration) reaches its envelope first. 7 refs., 7 figs., 2 tabs.