多阶式层级梯度蜂窝结构的共面冲击响应

In-Plane Impact Response of Multi-Order Hierarchical Gradient Honeycomb Structure

为改善蜂窝结构共面的力学性能,基于传统六边形蜂窝结构,建立了六边形层级蜂窝结构,并利用层级蜂窝代替传统六边形蜂窝部分胞元层,复合成一种新型多阶式层级梯度蜂窝结构。利用显式动力学有限元方法研究了层级梯度蜂窝的共面在不同冲击速度作用下的冲击响应特性和能量吸收能力。研究结果表明:层级梯度蜂窝的变形模式与塑性坍塌强度和冲击速度有关;层级梯度蜂窝冲击端和固定端在不同冲击速度作用下的名义应力-应变曲线均与其变形模式有关;不同的复合方式会导致层级梯度蜂窝具有不同的平台应力和比吸能,且在高速冲击时其平台应力比传统六边形蜂窝提高45.4%~63.8%,能量吸收提升10.8%~34.1%。相对密度会影响层级梯度蜂窝的能量吸收能力。

In order to improve the in-plane mechanical properties of honeycomb structure,a hexagonal hierarchical structure is established based on the conventional hexagonal honeycomb structure.The presented hierarchical one is used to replace part of the cell layer of the conventional hexagonal honeycomb,thus form a new type of multi-order hierarchical gradient honeycomb structure.The impact response characteristics and energy absorption capacity of the in-plane hierarchical gradient honeycomb under different impact velocities are studied through explicit dynamic finite element method.The results show that the deformation mode of the hierarchical gradient honeycomb is related to the plastic collapse strength and impact velocity;the nominal stress-strain curves at the impact end and the fixed end are related to its deformation mode under different impact velocities.Different composite methods will lead to different plateau stress and specific energy absorption of hierarchical gradient honeycomb.Its plateau stress is45.4%–63.8% higher and energy absorption is 10.8%–34.1% higher than that of the conventional hexagonal honeycomb under high-speed impact.The relative density will affect the energy absorption capacity of hierarchical gradient honeycomb.