A basic elastoplastic model (modified Cam-clay) was applied to wheat flour, a dry cohesive powder. Five constitutive parameters for the modified Cam-clay model have been previously determined for wheat flour using triaxial tests. To apply the elastoplastic constitutive model, a test cylinder was built that uniaxially compacted the wheat flour under constant axial displacement. Hoop and vertical strains in the cylinder wall were measured at three levels while the flour inside was compacted. Predicted vertical strains, using a finite element model (FEM), were within 25% (worst case error) of average measured values for all three levels up to 59.4 kPa axial pressure. Predicted hoop strains, at the cylinder bottom, were within 45% (worst case error) of average measured values up to 59.4 kPa. Along with predicting strains in the cylinder wall, the FEM also predicted stress distribution in the powder mass. Stress distribution proved useful in identifying potential regions of stress concentration and large shear stresses in the powder mass.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)