Results from tests with normal and shear stress cells in a medium-scale model silo

Results from tests with central filling and central and eccentric discharge of barley in a medium-scale model silo are reported. Special attention is paid to the description of recently installed shear cells and to results obtained with these. Equilibrium checks were carried out in the filling situation, showing that the friction load on the silo wall determined from shear cell measurements deviates about 3% when compared with the known weight of the grain minus the known bottom load. The deviations in two situations during central discharge were found to be 6% and 10%. It is concluded that the shear cells produce reliable results. Wall friction coefficients were found to be about 0.58 during central filling and about 0.43 during discharge. The very low pressure level in the silo model is supposed to be responsible for the high coefficient found during filling.