A PROPOSED PHENOMENOLOGICAL MODEL TO CHARACTERIZE MECHANICAL-PROPERTIES OF FLUE-CURED TOBACCO-LEAVES

It was determined that the visco-elastic behavior of four flue-cured t obacco leaves could be modeled by the equation; sigma(I) = E(I)epsilon + C(I)epsilon1+b + sigma(d); where sigma(I) = stress index (N/mm), E( I) = elastic index coefficient (N/mm), c(I) = non-linear elastic index parameter (N/mm), b = elastic exponent, mu = damping coefficient depe ndent on strain rate (N/mm) and d = damping exponent. The relationship between mu and strain rate was determined to be mu = GAMMAepsilon(bet a) where GAMMA = viscous constant (Ns(beta)/mm), beta = constant, and epsilon = strain rate (Lls). In all cases, the coefficient of determin ation (R2) Was above 95% thereby indicating that this phenomenological model can be used to describe the non-linear loading curve of these t obacco leaves. Results indicated the non-linear elastic parameter (c(I )) influenced the response of the tissue more than the linear elastic coefficient (E(I)). Viscous behavior was non-linear and resembled the characteristics of pseudoplastic flow.