Some mechanical properties and stress relaxation characteristics of lentils

Abstract

The modulus of elasticity and ultimate compressive stress of lentil kernels as influenced by mois ture content were determined. The effects of grain moisture content, deformation level, and two loading speeds (in uni-axial compres sion) on viscoelastic characteristics of lentils were studied. A three-term Maxwell model was found to adequately describe the relaxation characteristics with a maximum relative difference (MRD) of 5%, when compared with one- and two-term Maxwell models. The modulus of elasticity, compressive stress and elastic component (£i), and relaxation time constant (n) of the first term of three-term Maxwell model decreased with increase in moisture lev els. An empirical equation was proposed to express the combined effect of moisture, loading speed, and deformation level on E and Ti in the three-term Maxwell model. Moisture content had a significant influence on both of these parameters.