Transactions of the ASAE · 1983 · 12 citations · 0 references
Extruded Durum SemolinaEngineeringMechanical EngineeringMaxwell ModelsDesiccationElasticity (Physics)MechanicsStressstrain AnalysisViscoelastic BehaviorRheologyMoisture ContentMechanical BehaviorSolid MechanicsPlasticityMechanical DeformationMoisture Shift FactorsRelaxation BehaviorRheological Constitutive EquationMechanical PropertiesCivil EngineeringMechanics Of Materials
ABSTRACT UNIAXIAL tension tests at constant rates of elongation (0.02, 0.05, 0.1 and 0.2/min) were used to determine the relaxation behavior for moisture and temperature equilibrated specimens of extruded durum semolina. Moisture contents ranged from 0.12 to 0.25 dry basis and temperatures 42 to 58 C. Linear viscoelastic, thermo- and hydro-rheologically simple behavior were validated for experimental conditions. Data reduced for time-temperature and time-moisture equivalence was fitted to Maxwell models and used to express behavior over extended time scale. Expressions determined for the temperature and moisture shift factors using constant strain rate data were used to reduce the failure stresses with good results. The scatter of failure points about the reduced line had a standard deviation of 0.3 logarithmic units.