A multifunctional attachment piece with a multiple negative Poisson ratio effect

摘要

A multifunctional fastening piece with multiple negative Poisson's ratio effect, which is characterized in that it comprises a top part of the fastening piece, a round tube part of the fastening piece and a rear part of the fastening piece, the upper part of the fastening piece comprising a series of evenly distributed arcuate concave structures with negative Poisson's ratio, where the distance between the outermost concave angle of each bend and the neutral axis is D3, the outside diameter of the round pipe part is D2, the distance between the outermost concave angle of each bend and the outside of the round pipe (D3-D2) / Is 2, its relationship to the outer diameter of the round pipe part satisfies the following conditions: D2 / 20 (D3-D2) / 2 D2 / 8 and 2 mm (D3-D2) / 2, where the inner concave angle θ of each arc ranges from 50 ° to 70 °, the number N1 of arcuate concave bars on the top of the fastening The fitting piece fulfills the following condition: 9≤N1≤25, where the round pipe part of the fastening piece consists of an outer round pipe with a negative Poisson's ratio and a support structure with a negative Poisson's ratio, the number N2 of elements with a negative Poisson's ratio along the outer round pipe of the circumferential direction should meet the conditions: N2≥ 6 and N2is straight, where the relationship between the number N2 of elements with a negative Poisson ratio of the outer round tube along the circumferential direction and the included angle α between adjacent elements in the support structure fulfills the condition: α = 360 ° / N2, where the thickness D2 / 2-R1 of the outer round tube and the support structure should meet the following condition: D2 / 16≤D2 / 2-R1≤D2 / 8, where R1 is the inner diameter of the round tube part, the relationship between the The length L1 of the upper part of the fastening piece and the length L2 of the round pipe part of the fastening piece satisfy the following condition : 0.8 L2 / L1 2.5, where the relationship between the diameter D1 of the functional part at the rear of the fastening piece and the outer diameter D2 of the round tube part of the fastening piece satisfies the following condition: 1.1 D1 / D2, where the relationship between the diameter D1 of the functional part on the rear part of the fastening piece and the length L3 of the functional part on the rear part of the fastening piece satisfies the following condition: 3.5 D1 / L3 10.3.