Impact Simulation of Laser Powder Bed-Fused Polymeric Lattice Structures Using Mooney-Rivlin and Yeoh Hyperelastic Material Models: Calibration and Comparison

This study evaluates a methodology for the calibration of the 5-parameters Mooney-Rivlin and Yeoh 3rd-order hyperelastic material models for impact simulations on laser powder bed-fused TPU1301 lattices destined for personal protective equipment. To calibrate the models, bulk normalized specimens were printed and characterized using 400 mm/min uniaxial compression tests. Three 18% density 20-, 30- and 40 mm-thickness lattice structures, namely, Kelvin, body- and face-centered cubic, were manufactured and impact-tested. Using the material models, the impact tests were simulated using LS-Dyna, and their acceleration curves were compared with their experimental equivalents. The simulations accurately depicted the impact behavior of most lattices, but thicker specimens with lower peak accelerations and longer impact durations, such as the 40 mm Kelvin lattice, showed errors reaching 46 and 64% for the Yeoh and Mooney-Rivlin models, respectively. Furthermore, body-centered cubic lattices showed a softer behavior in simulations than experimentally. Overall, the Yeoh model provided the most accurate results across all topologies with an average error of 11.8% compared with 19.6% for Mooney-Rivlin. The methodology used in this study is therefore considered suitable for LPBF-printed TPU1301 lattice structures but would benefit from calibration at higher strain rates, biaxial and shear testing, and better meshing strategies.