Two-substructure, time-domain transfer path analysis of transient dynamic response of mechanical systems with nonlinear coupling

The traditional frequency domain transfer path analysis has become a popular method to detect and diagnose vehicle NVH (noise, vibration and harshness) problems. Unfortunately, due to its reliance on frequency transfer functions, the approach is strictly effective only for linear time-invariant system and steady-state response. This limitation prevents the method from being applied to transient and/or nonlinear behavior such as clunk, shudder, and tipin and tip-out. In this paper, a novel time domain transfer path analysis is proposed to deal with a class of non-linear transient response problems. It combines the versatility of the transfer path analysis for tracking transmission of vibratory energy between substructures and generality of the time domain analysis for treating transient response that is also nonlinear in nature. The formulation that is derived by combining the spectral-based substructure method and a discrete, piecewise convolution theory is applied to a lumped parameter system. Simulation results are found to compare well to the output from a direct numerical integration of the nonlinear equations of motion.