A MICROSTRUCTURAL MECHANICS MODEL FOR PREDICTING HYGROSCOPIC LOADS INGRAIN STORAGE BINS

A two-dimensional microstructural mechanics model has been developed f or predicting hygroscopic (moisture induced) loads in grain storage bi ns. The model assumes that the grain bulk consists of elastic spherica l kernels. The volumetric expansion of a grain kernel is approximated by the volume of water absorbed by the kernel. Hygroscopic microstress es are calculated from moisture induced microstrains which are determi ned from the volumetric expansion of the kernel. The microstructural m echanics theory is used to transfer these hygroscopic microstresses in to macroscopic stresses (or hygroscopic pressures) on the bin wall. Pr edicted hygroscopic loads are in close agreement (within 6%) with the reported experimental data.