Exploration of the optimum finite element modelling techniques for honeycomb structures for non-pneumatic tyre applications

Honeycomb spokes are among the most commonly used structures in non-pneumatic tyre (NPT) research and development. Even though finite element (FE) modelling plays a key role in this effort, there is still a lack of knowledge regarding the requirements for accurate FE simulation of the mechanical behaviour of NPT honeycomb structures. The use of an inappropriate FE type can lead to misleading results and act as a barrier for robust research and development. To address this gap in literature, the present study explores the optimum FE type for different relative dimensions of honeycomb NPT spokes. To this end, NPT segments with honeycomb spokes were 3D printed from TPU95 and subjected to compression tests. FE models were created using different element types (2D-plane quadrilaterals/triangles and 3D shell, higher order) to determine their accuracy when used in structures with varied spoke thickness-to-height ratios. 3D shells proved to be the optimum choice at predicting the required load for initial buckling for thickness-to-height ratios of 1/18 or smaller, and 2D plane elements (both quadrilaterals and triangles) proved optimum for ratios of 1/12 or larger.