【摘要】 采用数值模拟方法,研究了具有手性和反手性构型的负泊松比蜂窝(统称手性系蜂窝)在不同冲击速度下的变形模式和能量吸收等动态力学响应特性。结果表明,低速冲击下,其变形模式为连接带和圆孔的先后坍塌;高速冲击下,为圆孔和连接带交替坍塌的逐层压溃;在中等速冲击下,为兼有低速和高速模式部分特征的过渡模式;随着冲击速度的提高,局部变形区逐渐集中于冲击端。并且,在中、低速冲击时,能观察到手性系蜂窝的动态负泊松比效应。此外,数值模拟结果使我们对这类二维负泊松比多孔材料的动态力学性能和能量吸收性能有了一定的认识,同时为进一步研究三维负泊松比泡沫材料的冲击行为奠定了基础。更多还原

【Abstract】 The deformation modes and energy absorption properties of chiral and anti-chiral honeycombs with negative Poisson’s ratio under in-plane dynamic crushing were studied by means of numerical simulations. The results show that the deformation mode of the chiral family honeycombs at low impact velocities consists of two different stages:the first is the collapse of the ligaments and then is the collapse of the circular nodes. The deformation mode appears as the crushing of circular nodes and ligaments layer by layer at high velocities and a transitional mode with part features of both the low and high velocities modes at moderate velocities. The localized bands transit from the fixed end to the impact end as the impact velocity increases. When the velocity is low or moderate,the chiral family honeycombs display the dynamic auxetic responses. The results provide us a certain understanding of the dynamic behaviors and energy absorption properties of two-dimensional auxetic cellular materials and lay the foundation for understanding the impact behaviors of three-dimensional auxetic foam materials.更多还原