Dynamic response of a 3D-printed TPU non-pneumatic tyre under obstacle traversal and vibratory excitation

Non-pneumatic tyres are gaining interest for lightweight off-road mobility because they eliminate dependence on inflation pressure and enable mechanical behaviour to be tailored through structural design. However, controlled comparisons with conventional pneumatic tyres under impact and vibration conditions remain limited. This study evaluated the static and dynamic response of an additively manufactured thermoplastic-polyurethane (TPU) non-pneumatic tyre with a graded V-shaped spoke architecture and compared it with a conventional pneumatic tyre under equivalent loading conditions. Static compression tests were used to characterise the load–displacement response and to support qualitative interpretation using a finite element model. Dynamic performance was assessed through obstacle-traversal tests at 3 and 6 km h−1 over semicircular obstacles with radii of 3, 6 and 9 mm, and through vibration tests using sinusoidal excitation at 4, 8 and 15 Hz and broadband pink-noise excitation from 50 to 250 Hz. The static tests showed force relaxation and a nonlinear increase in secant stiffness from 25.0 to 33.8 N mm−1 between 2 and 8 mm displacement. Peak acceleration increased with obstacle size and speed, but no statistically significant difference was detected between the two tested tyre specimens under any matched traversal condition. The non-pneumatic tyre achieved greater positive vibration attenuation than the pneumatic tyre, reaching 14.22%, 25.80% and 49.48% at 4, 8 and 15 Hz, respectively, and 38.84% under broadband excitation. Under the tested lightweight conditions, the manufactured TPU tyre improved vibration isolation, although further testing with independently manufactured specimens is required to establish production repeatability and tyre-to-tyre variability.