A design method for force-limited vibration testing conditions

This paper proposed a design method for force-limited vibration testing conditions based on the complex two degrees of freedom system (TDFS) model. This method adopted the dynamic sub-structure theory to calculate the modal effective mass and the residual mass of the test article structure and the supporting structure, determined the specific parameters of the complex TDFS model in different bands depending on their distributions. The force spectrum and the acceleration spectrum of the contact surface between test article and supporting structure were defined with the excitation conditions of supporting structure. On the basis of the envelope, the force limited vibration test profile was obtained. Simulation results showed that the force-limited vibration testing conditions given by this method reflect the vibration environment of the test article much more realistically compared to the conservative testing conditions of the traditional acceleration-controlled vibration test.