Test, Benchmark and Fine-Tune Complete Axle Systems

Noise, Vibration and Harshness (NVH) optimizations are often required late in the development process. However, more and more OEMs are considering addressing these issues much earlier to avoid late, difficult and costly changes.

We support these efforts with our axle test bench, which allows to test, benchmark and fine-tune complete axle systems in an early development phase as well as to troubleshoot in any stage of the vehicle lifecycle. Due to our NVH expertise we know how our products behave and react in an axle subsystem as well as in the full vehicle. With over 80 axles benchmarked, we have unique expertise and are able to derive NVH market trends from these findings.

Vibration control requirements for noise, vibration, and harshness (NVH) in vehicles are generally involved in the development process at a late stage, subsequently presenting developers with significant challenges. There are two main reasons for this. Firstly, suitable vehicles with the necessary maturity level justifying vibration control efforts are only available very late. Secondly, the simulation of vibration control properties is more difficult than the simulation of driving dynamics, where corresponding tools are already available in large numbers and with a high degree of reliability.

The Vibracoustic axle test bench provides a unique measurement procedure for evaluating the NVH performance of the axle subsystem. It involves measuring forces acting at the interfaces between the axle and the vehicle body, which allows conclusions to be drawn relating to vehicle noise.

Using transfer path analyses (TPA), relevant acoustic transfer paths from the excitation all the way to the passenger’s ear can be additionally identified and potential courses of action evaluated. Rapid loops between the system evaluation and modification of component properties are possible due to the global network of prototyping facilities, enabling the quick exchange of prototype parts.

The axle test bench can cover a wide range of relevant road noise frequencies and is able to investigate frequencies up to 2 kHz. In this way, Vibracoustic meets the needs of many light vehicle manufacturers who incorporate road noise performance early in the development process for the NVH evaluation of individual hardware variants. 

With an axle optimization workflow, which helps to reduce workload and enables tasks to be prioritized, Vibracoustic can thus further support the axle development process. Test bench measurements are used to validate an axle simulation model.

By simulation and optimization, the most effective component modifications are identified, which are designed, built and implemented afterwards. Counter-measurements with updated components are done with the axle before the final proof is done in the full vehicle.

With its latest e-NVH update, the axle test bench can also investigate and benchmark electric powered axles (e-axles). The e-motor can be powered in the axle directly, both in acceleration and recuperation, without the need to have the full car on site. The necessary battery as well as the hard- and software can be simulated on site, which makes it much easier to realistically investigate the NVH behavior of an e-axle very early in the development phase when there might not even be a full chassis and car body developed yet.

Extensive system expertise, corresponding simulation methods, associated prototype construction, and comprehensive benchmarking infrastructure including component and full vehicle testing, enable Vibracoustic to support OEMs to benchmark, evaluate, test and define NVH specifications and requirements for their vehicles as early in the development process as possible. This not only helps save time and costs, but it also secures optimized NVH performance and driving comfort.