Transactions of the ASAE · 1979 · 22 citations · 0 references
Natural SciencesMaterials EngineeringMaterials ScienceBiomechanicsMechanical Behavior Of MaterialsRheologyElastic PropertiesMoisture AnalysisRheology Of Biological MaterialsStress RelaxationViscoelastic BehaviorViscoelastic PropertiesGeneralized Maxwell ModelMaxwell ModelMaxwell Viscoelastic ModelMoistureMoisture ContentMoisture Content DependenceMoisture Content EffectsRelaxation Modulus
ABSTRACT THE mechanical properties of biological products, because they vary with both temperature and moisture content, have been difficult to describe by single mathematical models of stress or strain versus time. This paper describes the determination of temperature and moisture shift factors to include both parameters in the single equation of mechanical response. Soybeans were studied as a viscoelastic material at four temperatures and at four moisture levels employing stress relaxation techniques. Product response was characterized by a generalized Maxwell model. The uniaxial relaxation modulus function was plotted against time, and, from this, temperature and moisture shift factors determined. Soybean mechanical response was found to be both thermo-rheologically and hydro-rheologically simple.