Investigation of the C(2) parameter of force limited vibration testing for multiple degrees-of-freedom systems

Abstract

The semi-empirical method of force-limited vibration testing is used in the aerospace industry to avoid over-testing. The semi-empirical method specifies the maximum interface force based on a single parameter, often referred to as C2, which is based on previous experience with similar structures. This thesis investigates the factors influencing the value of C2 associated with semi-empirical force limited vibration testing. First, a base excited two degrees-of-freedom system is examined in context of the semiempirical method. Then, the effect of different types of damping is investigated. The work is then extended to multiple degrees-of-freedom and continuous systems where a new method, based on the apparent mass, of determining the value of C2 is presented. Finally, experimental testing is utilized to validate the conclusion and the predictions of the new method.