GO FASTER
The most comfortable ride on the road
How integration of virtual simulation and physical test are helping Hyundai Motor Group to optimize their NVH performance.
By Luke Morris
For most modern road users, comfort is a key factor when it comes to choosing a vehicle.
With speeds limited by both traffic and regulations, different cars will get you to your destination in a similar amount of time. And the vast majority of vehicles are built to the highest safety standards to ensure you arrive unharmed.
Getting you there in the most comfortable way is the biggest differentiator a manufacturer can make.
So, what makes a vehicle comfortable?
An ergonomically designed seat? Sure. But it’s about much more than that.
Rattling body work, whistling winds, the sound of the tires on the road surface. All of these can add up to an unpleasant, uncomfortable experience.
Now, with the rise of electric vehicles, road noise is even more of an issue as it is no longer masked by an internal combustion engine.
Manufacturers need to adopt new design technologies to improve NVH performance and stand out in a crowded marketplace.
Integrating test and simulation model
To help realize its goal of becoming the number one electric vehicle manufacturer in the world, Hyundai Motor Group (HMG) has transitioned to an integrated modular architecture (IMA) strategy. This allows for the same part to be used in multiple vehicle models, thus reducing overall development costs. While HMG is adopting this new approach for all vehicles, it’s particularly useful for electric vehicles as batteries can be developed to attach flexibly to any automotive model.
Knowing that virtual development would be vital for the accuracy and speed of the new process, HMG senior research engineer, Sangyoung Park from the driving comfort virtual development team, formed a strategic partnership with Simcenter™ Engineering and Consulting services to aid them in getting the most value from products within the Siemens Xcelerator portfolio.
“Three years ago, we set out on a mission to define the test engineer’s role for the virtual development environment,” explains Park. “We began by focusing on developing test models that would be compatible with our simulation models. However, I faced significant obstacles when attempting to create perfectly compatible test models, so we turned to Simcenter Engineering and Consulting Services for help.”
“We selected Simcenter Engineering Services because we knew they could help us transform our vision into an actionable, realistic roadmap for implementation,” says Park. “They have developed proven methodologies and experience for integrating hardware and software to achieve balance between practical application and technology advancement.”
Authoring system models experimentally
A key aspect of reducing road noise is understanding the invariant loads from a vehicle’s tires. Together with Simcenter engineers, the HMG team applied component-based transfer path analysis (TPA) at the wheel level to determine these blocked forces which are invariant to the receiving structure.
They also used Simcenter Virtual Prototype Assembly (VPA) to combine the invariant loads with virtual vehicle assembly variants and predict the resulting road noise performance.
They also used frequency-based substructuring (FBS) decoupling to accurately represent the subsystem in its realistic operational boundary conditions and identify unknown components’ frequency response functions (FRFs).
This led to the building of a customized bench to accurately and repeatedly test the suspension and further optimize the design – a world-first in FBS-based assembly analysis.
“When I suggested our idea for acquiring a suspension model, I wasn’t sure it was achievable,” says Park. “However, Siemens integrated hardware, software, and component based TPA testing enabled us to design a very challenging jig flawlessly. Additionally, various techniques learned from other test campaigns were used to successfully make on-the-fly changes. The progress we’ve made is encouraging and will help us prepare future models to evaluate performance at the early stages of development.”
Assembling test and simulation models for NVH performance prediction
The next stage was to build a virtual vehicle assembly based on the test and simulation models such as tire, suspension, bush or body. This allows for NVH performance to be predicted as reliably as possible and enables much faster design optimization in the the early stages of vehicle development.
Subjective evaluation in the early stages
The work doesn’t stop here.
The partnership is now focused on customizing Simcenter VPA to meet HMG’s specific needs. Ultimately, they are able to listen to the sound of a vehicle in development before a physical prototype has even been built. Simcenter™ Testlab™ NVH simulator will combine road noise with other noises such as wind, tires, and powertrain to make performance prediction even more accurate and allow for earlier design changes.
HMG’s engineers are in no doubt as to the benefits the partnership will bring as they continue to strive to design the most comfortable vehicles on the market.
“The outcome of our research with Simcenter Engineering Services is that we can now use objective and subjective evaluation platform integrating both simulation and test models virtually for developing our vehicle architecture NVH performance,” says Park. “Virtual development using integration of simulation and test models is increasing cooperation with foreign offices such as HMETC and tire suppliers to make HMG vehicles more comfortable and enjoyable to drive.”
