Bull. Spec. CORESTA Congress, Guangzhou 1988, p. 162, T-10
Exploring mechanical properties of tobacco leaf lamina
Philip Morris USA, Research Center, Richmond, VA, USA
This study provides us with an estimate of the overall mechanical properties of cured tobacco leaf lamina. Stress-strain tests were performed to determine modulus, yield strength, and toughness (energy to break) of lamina when deformed under tension and simple shear loads. Microscopic observation of deformed samples showed an uneven stress distribution and anisotropy. The macro scale phenomenological results indicated a harmony in its mechanical behavior. Lamina uniformity and in-plane homogeneity and the effects of stalk position and types of tobacco were also investigated. The relationship between tension and shear properties was also obtained. Both in shear and tension, lamina seem to become softer with an increase in load. The stress-strain behavior can be characterized by a two-parameter power law equation. Statistically estimated results did not indicate any significant differences in their mechanical properties. The material appears softer but tougher in shear than tension. It also showed sensitivity to the rate of deformation, indicating viscoelastic nature of its behavior. Thus, we see, even though at the micro level cured tobacco lamina is heterogeneous and anisotropic, at the macro level it displays homogeneous and uniform mechanical properties.