Elastic Properties of the Tobacco Leaf

A stress-strain model was determined for elastic parameters of the tobacco leaf that permitted comparison among leaves of different characters. Tests were made (1) on leaves from three stalk positions, (2) at two rates of loading, and (3) at four nominal leaf moisture contents. Tangent modulus at the inflection point and the secant modulus at failure were discovered to be the most definite basis for differences observed in model curves due to stalk position, loading rate and moisture contents. The coefficients of the last two terms of the model also showed some potential as indicators of elasticity at lower moisture contents. The most effective separation of effects occurred below 20% moisture content (w.b.). Energy absorbed and stress and strain values showed variation with treatment but lacked repeatability across treatments to be used as indicators of leaf character. Elastic parameter values were affected by rate of loading as well as moisture content and effective evaluation will require identification of both.