Sun Yongtao, Pugno Nicola
Laboratory of Bio-Inspired Nanomechanics "Giuseppe Maria Pugno", Department of Structural, Geotechnical and Building Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino 10129, Italy.
Laboratory of Bio-Inspired and Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano 77, Trento I-38123, Italy.
Materials (Basel). 2013 Feb 22;6(2):699-712. doi: 10.3390/ma6020699.
In this paper, a new kind of hierarchical tube with a negative Poisson's ratio (NPR) is proposed. The first level tube is constructed by rolling up an auxetic hexagonal honeycomb. Then, the second level tube is produced by substituting the arm of the auxetic sheet with the first level tube and rolling it up. The th ( ) level tube can be built recursively. Based on the Euler beam theory, the equivalent elastic parameters of the NPR hierarchical tubes under small deformations are derived. Under longitudinal axial tension, instead of shrinking, all levels of the NPR hierarchical tubes expand in the transverse direction. Using these kinds of auxetic tubes as reinforced fibers in composite materials would result in a higher resistance to fiber pullout. Thus, this paper provides a new strategy for the design of fiber reinforced hierarchical bio-inspired composites with a superior pull-out mechanism, strength and toughness. An application with super carbon nanotubes concludes the paper.
本文提出了一种新型的具有负泊松比（NPR）的分层管。第一级管是通过将一种拉胀六边形蜂窝卷起来构建而成。然后，通过用第一级管替代拉胀片材的臂并将其卷起来来制造第二级管。第n级管可以递归构建。基于欧拉梁理论，推导了小变形下NPR分层管的等效弹性参数。在纵向轴向拉伸下，NPR分层管的各级不是收缩，而是在横向方向上膨胀。将这类拉胀管用作复合材料中的增强纤维将导致更高的抗纤维拔出能力。因此，本文为设计具有优异拔出机制、强度和韧性的纤维增强分层生物启发复合材料提供了一种新策略。本文以超级碳纳米管的应用作为结尾。
