RELATING THE VALUE OF C2 OF THE SEMI-EMPIRICAL METHOD OF FORCELIMITED VIBRATION TO A 2-DOF SYSTEM

摘要

The semi-empirical method used in force limited vibration testing specifies a constant called C2to predict force limits during random vibration testing. Typically the C2 has been found to bebetween 2 and 5 for aerospace structures [Chang et al. 2000, Dharanipathi 2003, Scharton 2001,Salter 1964]. This paper examines how the value of C2 varies with mass ratio, frequency ratio,and damping for a lightly damped 2-DOF system. The results show that although both frequencyratio and mass ratio are important parameters, it is the frequency ratio, as opposed to mass ratio,that is the dominant factor in determining C2 when the frequency ratio is not unity as is typicallythe case by design for the main first mode of aerospace structures.