In-situ Decoupling and Stiffness Optimization of Resiliently Coupled Assemblies Using FRF-Based Substructuring

Resilient mounts are critical in controlling vibration transfer from sources such as engines, motors, and suspension to the vehicle structure. Conventional optimization methods rely on finite element analysis (FEA), which, while accurate, is computationally intensive and limits iterative NVH development. This paper introduces a Frequency Response Function Substructuring (FBS)-based approach that decomposes the system into substructures characterized by FRFs, significantly reducing computational cost without compromising accuracy. Key contributions include: (1) recovering subsystem FRFs from coupled system data in-situ for mount optimization, (2) extending FBS to handle enforced motion, and (3) proposing an alternative strategy for cases with unknown or unmeasurable loads. The methodology is demonstrated on a mid-size pickup truck model to optimize seat track response under a Four post shake load by refining body mounts. These advances broaden the applicability of FBS for efficient NVH optimization in complex systems.