How Virtual Points, Component TPA, and Frequency-Based Substructuring Disrupted the Vehicle Suspension Development Process

The high competition in the automotive industry has led to ever-shorter development cycles and the introduction of modular vehicle designs. To succeed in this environment, engineers need to be able to make quantitative design suggestions as early as possible. For NVH engineers, this means, for example, making an optimal choice for the suspension bushings to compromise between driving dynamics, ride comfort, noise, and durability. This is a task wherein decisions involve many stakeholders, design parameters, and targets, and these need to be made before the first physical prototype exists. Thus, early-phase insights are crucial. In this chapter, we show how NVH engineers conquer these challenges by applying state-of-the-art methods from structural dynamics: first, the source excitation and noise propagation are separated using component TPA. Then, a model of the car suspension, including all the bushing degrees of freedom, is measured using the virtual points. The bushing stiffnesses are virtually modified using a frequency-based substructuring method called stiffness injection (SI). The bushing parameters are optimized using the genetic algorithm. Our results show how the combination of these technologies allows us to efficiently produce optimal design choices considering various driving conditions, target quantities, and design constraints. It furthermore shows how modern software design easily allows this to become an integral part of the standard vehicle development process.