Predicting grain consolidation caused by vertical vibration

A theoretical model was developed to predict vibration induced grain consol idation (vertical settlement) in storage bins. In the theory, grain kernels were modeled as spheres connected by elastic springs and frictional damper s. Governing differential equations were then developed for this spring-dam per system and solved numerically Ir was hypothesized that grain consolidat ion was resulted from grain kernels being "pushed" into the adjacent layers by the inertial force during vibration, An experiment was conducted to mea sure grain consolidation in a small model bin filled with wheat to validate the predictive model. The bin was subjected to vibration at frequencies of 23, 30, and 48 Hz and amplitudes up to 2.3 mm, The predicted grain consoli dation compared favorably with the experimental data. It was found that the maximum consolidation (density) was independent of the vibration frequency However the higher the frequency, the lower the amplitude at which the max imum consolidation (density) occurred. Both the vibration amplitude and fre quency affected the variation of grain consolidation with the grain depth.