Speaker
Description
To accurately predict vehicle NVH performance, subsystem-level validation should be conducted prior to full vehicle development. The Load Transfer Ratio (LTR) is widely used to evaluate force transmission characteristics of suspension systems. However, its reliability strongly depends on how the suspension input force is defined. This study focuses on the identification of suspension input forces for LTR evaluation, rather than direct LTR measurement. Conventional methods rely on dynamic force sensors, which inevitably include excitation system dynamics. To overcome this limitation, a Frequency-Based Substructuring (FBS) hybrid model is developed to identify wheel-center interface forces independently of actuator boundary conditions. Blocked forces at the excitation interface are obtained using an in-situ Transfer Path Analysis (TPA) method and combined with experimentally measured transfer functions through FBS synthesis to derive representative suspension input forces. To assess the influence of input force identification methods, the results are compared with forces obtained using a classical TPA approach. All forces are transformed to the wheel-center reference using Virtual Point Transformation (VPT) and represented as six-degree-of-freedom force vectors, enabling reliable LTR-based suspension NVH assessment.