Virtual part development a ‘paradigm shift' in automotive

AKRON—Virtual product development may not be as predominant a trend as electrification in the automotive industry, but it is no less critical, according to Josh Goossens, materials engineering manager at Tenneco's Clevite Elastomers Group.

Goossens focused on the movement being pushed by automotive OEMs for cost-savings and faster time-to-market potential during his keynote presentation May 11, the second day of the Rubber News-organized Rubber in Automotive Conference.

"This is a bit of a different topic than the electrification and sustainability that has been discussed here so far this week," Goossens said. "Virtual product development represents a paradigm shift in automotive."

Clevite Elastomers, part of the performance solutions business at Tenneco, makes ride control and NVH products for OEMs and aftermarket customers. The antivibration products—typically comprising a majority natural rubber compound—are part of the foundation for an automobile as chassis-frame pivot points.

And as OEMs push for the full virtualization of product development, that should put Tenneco and Clevite toward the front of the line in the manufacturing process.

But that has not always been the case, and virtual product development presents further challenges in that regard.

"We are in the process of getting the requirements from OEMs to virtually design the products, where the first physical parts produced will be off of production tooling and of sellable vehicle quality," Goossens said. "Let that sink in ... think about your own production lines.

"Are you ready for this type of future where there will be no prototyping, producing sellable quality parts that were designed from a purely virtual standpoint?"

Goossens has been with Tenneco since 1999 in various roles. He is responsible for elastomer compound development, material selection, mixing process development, core material research and material property testing for simulations.

And he is the manager to lead the Clevite division into this virtual world, as his favorite area of research is the development of new material testing techniques for the advancement of product simulation accuracy.

In this capacity, Goossens and the Clevite division work directly with Findlay, Ohio-based Endurica L.L.C. for fatigue testing of bushings and other parts.

Clevite was founded as Harris Products Co. in 1933, pioneering elastomer suspension products for chassis. The company was acquired by Pullman Co. in 1987 (when it became Clevite Elastomers); and again by the Northville, Mich.-based Tenneco in 1996.

The company is vertically integrated for design, compound development, fabrication, testing and product characterization, Goossens said.

There are a lot of rubber products on any vehicle, and the pivot points on a chassis and frame are no different, require a bushing made of rubber and steel (or other rigid material).

In fact, the components are agnostic to both EVs and ICE vehicles—meaning that the power train of the vehicle makes no difference to Clevite for its bushings.

For Clevite and Goossens, the philosophy should be one of vibration isolation, not attenuation.

"In seeing the talks yesterday and from what I have seen over 25 years in the industry, a lot of chemical companies think of antivibration products as working on a principle of attenuation," Goossens said. "But it really is a principle of vibration isolation. And this means using a low-damping compound for the pivot points."

From a formulation standpoint, bushings are on the simple side, Goossens said. Data required during development includes the optimum loads and strains for "a clean, lightly reinforced, high-quality NR compound," he said.

Process oil, antidegradants and carbon black round out the ingredients, and the bushings typically are prototyped with normal activators and cure systems.

But in the virtual world, the cart needs to come before the horse—the material behavior needs to be understood completely before any simulation can be done.

And that represents a lot of work by a potential OEM or aftermarket supplier before they even are selected for the work.

"They are asking us to simulate a broader range or production variations, introduce or increase the number of learning models and eliminate production variation for state of cure and other steps," Goossens said. "They are asking us for this, but what they have not done is given us how they expect that future to be realized."

Goossens estimates about a two-year launch cycle for Clevite's bushing products, where there would be a third technical review (in addition to the typical two technical reviews) before any business is awarded.

And in this case, the software, rather than hardware, will receive part validation.

"Again, that already is a lot of simulation work when we have not yet been selected as the supplier," he said. "And this is the core message of my talk: We need more material data."

And such material data—between eight and 20 times as much for full virtual product development as typical prototyping methods—is needed up front.

"That effectively eliminates the introduction of new material technology into a part because we need to fully understand the material behavior before we can do the simulation work," he said. "We can introduce new material tech or new mixing processes and validate that particular part of it, but it takes 1,600 machine hours and 40 labor hours for a technician to do it."

Goossens noted that even a "simplified" simulation model requires "quite a bit more data than a prototype in the first place."

"So the question remains: Are there any shortcuts possible with a full material data set? And how does all this align with cost to validate a prototype? That remains to be seen," he said.

"OEMs are pushing this from a very high senior management level. And the entire process is quite difficult."

As with any technological advancements, time-to-market is expected to be faster. But will a cost savings be realized?

"I think this will be a journey for elastomer component suppliers, especially in the antivibration space," Goossens said. "There is the potential for cost-savings ... but they like to treat our products as the last products to get adjusted.

"OEMs have to be more precise and accurate with their requests. If there is a major change request by an OEM late in the process, that means that all of our simulations are out the window. And the simulations we are doing are before we have been awarded the business.

"These are the problems we are facing right now."