Poisson's ratios of honeycomb-structured polymer sheets under large deformation

The mechanical properties of 2D honeycomb-structured polymer sheets (HSPS) are investigated with respect to the polar angle at large deformation. The tensile force fluctuates as an undamped negative sinusoidal wave with a periodicity of 15°. The amplitude of the fluctuation is proportional to the thickness of the HSPS, but the Young's modulus is independent of the thickness and the polar angle. Total and local Poisson's ratios of HSPS at the 30° polar angle are lower than those obtained at the 0° polar angle over the entire strain range, and the difference becomes smaller with increasing tensile strain. The experimentally observed structure-property relationship of the HSPS can provide important clues for understanding the deformation behavior of patterned polymeric materials.