Study on buffer performance of TPU material with negative Poisson’s ratio structure

DOI:	10.11809/bqzbgcxb2024.02.038
Keywords:	negative Poisson’s ratio structure; mechanical properties; numerical simulation; 3D printing; multi objective optimization design
Abstract:	Aiming at the problem that the current bulletproof helmet foam pad cannot absorb enough energy when the helmet is blunt hit by a bullet, the energy absorption characteristics of 3D printed negative Poisson’s ratio structure flexible pad were studied. Using thermoplastic polyurethane (TPU) as raw material, TPU tensile and compressive specimens were manufactured using 3D printing. The effects of printing process parameters (printing speed, printing temperature, and delamination thickness) on the mechanical properties of flexible materials were studied; Different sizes and specifications of negative Poisson’s ratio structures were designed and quasi static compression tests were conducted. Finally, finite element simulation and experimental results were compared. The results show that the mechanical properties of the printed specimen are optimal when the printing layer height is 0.1 mm, the nozzle temperature is 200 ℃, and the printing speed is 15 mm/s; The energy absorption capacity of the negative Poisson’s ratio structure increases with the decrease of the length of the horizontal and curved cell walls, and increases with the increase of the cell wall thickness. There is no obvious pattern of the angle between the structure and the cell wall; Subsequently, through multi objective optimization design, the optimal structure of the negative Poisson’s ratio structural cell was determined, and the specific energy absorption was significantly increased compared to the structure before optimization.
Published:	2024-02-28
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