Simulation of rubber materials is one area with much room for improvement.
"As I tried to improve the accuracies of the simulations I was working on, I kept butting my head up against the material representation and characterization," he said. "How do you get those better?"
Kennedy added that he wasn't looking to assess blame, just trying to emphasize the need to get better.
There are many ways to get models of materials, so it is important to determine which are best for use in tire development projects. For example, he found one model that worked well at room temperature, but another that was superior at elevated temperatures. That shows the need, he said, for a physical model that truly represents the materials in use.
Kennedy added that material modeling must run quickly, so the other parts of development can go forward.
"You have to represent the physics and you have to represent the chemistry," he said, "but we can't spend days waiting for an answer because our tire development engineers have to get that spec out and get that mold drawing out. If you don't deliver your results on time, they'll just leave without you."
The keynote speaker added that compound material characterization must deal with real tire operating conditions, and that information is needed beyond modulus and hysteresis, including such variables as more realistic and accurate friction representation.
Tire and material development currently are developed in separate parts within a tire company, and that must change.
The goal of simulations is to conduct product development in the virtual world before a physical sample is made; make an improved product quicker and with less cost; and give an insight into cause-effect relationships that can be leveraged to produce a better product.
Kennedy said that these principles hold true for both tires and materials, and the ability to bring the two areas together and eliminate silos in research and development would be a major step forward.
"Is there a way to take and build virtually to save on time and costs and tests?" Kennedy asked. If this can be accomplished, he said it's likely results will improve, and tire companies can "get the best tire out the door."