Lim Teik-Cheng
School of Science and Technology, Singapore University of Social Sciences, Singapore 599494, Singapore.
Materials (Basel). 2018 Jan 31;11(2):223. doi: 10.3390/ma11020223.
While the rule of mixture is applicable for addressing the overall Poisson's ratio of a concentrically aligned bi-layered rod under longitudinal loading, the same cannot be said for this rod under torsional loading due to the higher extent of deformation in the rod material further away from the torsional axis. In addition, the use of adhesives for attaching the solid inner rod to the hollow outer rod introduces an intermediate layer, thereby resulting in a tri-layered concentric rod if the adhesive layer is uniformly distributed. This paper investigates the effect of the adhesive properties on the overall auxeticity of a rod consisting of two concentrically aligned cylindrical isotropic foams with Poisson's ratio of opposite signs under torsional loads. An indirect way for obtaining Poisson's ratio of a concentrically tri-layered rod was obtained using a mechanics of materials approach. Results show that the auxeticity of such rods is influenced by the adhesive's stiffness, Poisson's ratio, thickness, and radius from the torsional axis.
虽然混合法则适用于解决纵向加载下同心排列双层杆的整体泊松比问题，但对于该杆在扭转载荷下的情况则不然，因为离扭转轴较远的杆材料变形程度更高。此外，使用粘合剂将实心内杆连接到空心外杆会引入一个中间层，如果粘合剂层均匀分布，就会形成一个三层同心杆。本文研究了粘合剂性能对由两个同心排列的圆柱形各向同性泡沫组成的杆在扭转载荷下整体负泊松比特性的影响。使用材料力学方法获得了一种间接方法来确定同心三层杆的泊松比。结果表明，这种杆的负泊松比特性受粘合剂的刚度、泊松比、厚度以及离扭转轴的半径影响。
