Obtaining a Swept Sine on Random Vibration Profile for Powertrain Mounted Component Qualification

As part of the design and validation of engine-mounted components, it is essential to define the vibratory mechanical environment in which these components will operate. This is required in order to optimize the reliability of such components subjected to loading from both the engine and road profile, while minimizing development costs and time scales.

This paper presents a methodology that superimposes a swept sine on a power spectral density of acceleration in order to evaluate the mechanical durability of engine mounted or gear box mounted components. The first step in the process is to obtain the wave form of the dominant engine orders by extracting the deterministic signals from the random process using an order tracking method in the time domain. The second step is to assess the fatigue damage and extreme response spectra of a Swept-Sine-On-Random profile. The third and final step is to develop the test profile by superimposing the harmonic and random parts to define a Swept-Sine-On-Random loading function that includes the customer's engine usage profile. Two use cases are presented to show the application of this methodology for industrial engines.