US 11,731,389 B2
Graded lattice energy-absorbing structure, chiral cell thereof having programmable stiffness, and 3D printing method
Dongdong Gu, Nanjing (CN); Jie Gao, Nanjing (CN); Chenglong Ma, Nanjing (CN); Yingjie Song, Nanjing (CN); and Wei Chen, Nanjing (CN)
Assigned to NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS, Nanjing (CN)
Appl. No. 17/796,919
Filed by NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS, Nanjing (CN)
PCT Filed Aug. 25, 2021, PCT No. PCT/CN2021/114459
§ 371(c)(1), (2) Date Aug. 2, 2022,
PCT Pub. No. WO2022/042580, PCT Pub. Date Mar. 3, 2022.
Claims priority of application No. 202010890835.4 (CN), filed on Aug. 29, 2020.
Prior Publication US 2023/0053918 A1, Feb. 23, 2023
Int. Cl. B32B 3/20 (2006.01); B32B 3/14 (2006.01); B32B 15/01 (2006.01); B33Y 10/00 (2015.01)
CPC B32B 3/20 (2013.01) [B32B 3/14 (2013.01); B32B 15/01 (2013.01); B33Y 10/00 (2014.12); B32B 2307/51 (2013.01); B32B 2307/558 (2013.01); B32B 2307/56 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A graded lattice energy-absorbing structure established based on a chiral cell having programmable stiffness, wherein, the chiral cell having programmable stiffness comprises a cell structure, the cell structure comprises an upper ring, a middle ring, connecting rods, and a lower ring, the connecting rods comprising a plurality of upper connecting rods and a plurality of lower connecting rods, wherein,
the upper ring and the lower ring have the same geometrical shape, and the middle ring is located between the upper ring and the lower ring; and axes of the upper, middle, and lower rings all coincide with a central axis of the cell structure;
the plurality of upper connecting rods is provided; two ends of each upper connecting rod are respectively correspondingly connected to the upper ring and the middle ring and the upper connecting rods are obliquely and uniformly distributed between the upper ring and the middle ring; and moreover, the upper connecting rods are arranged in different planes with respect to the central axis of the cell structure, and an angle θ is formed between each upper connecting rod and the central axis of the cell structure; and
the plurality of lower connecting rods is provided; two ends of each lower connecting rod are respectively correspondingly connected to the lower ring and the middle ring and the lower connecting rods are obliquely and uniformly distributed between the lower ring and the middle ring; and moreover, the lower connecting rods are arranged in different planes with respect to the central axis of the cell structure, and an angle −θ is formed between each lower connecting rod and the central axis of the cell structure, wherein,
the graded lattice energy-absorbing structure comprises two or more cell layers arranged in tiers;
each cell layer comprises several cell structures with the same stiffness; and the stiffness of the cell layers arranged in tiers shows a gradient change from top to bottom;
for the cell structures in the same cell layer, the upper rings and the lower rings of two adjacent cell structures are both connected via beams, while the middle rings of two adjacent cell structures are alternately arranged;
between two adjacent cell layers, the cell layer located on the upper side is an upper-side cell layer, while that located on the lower side is a lower-side cell layer; and
the cell structures of the upper-side cell layer and the cell structures of the lower-side cell layer are coaxially arranged in a one-to-one correspondence manner; and the lower rings of the cell structures in the upper-side cell layer and the upper rings of the corresponding cell structures in the lower-side cell layer are integrally connected or integrally designed.