A principal stress cap model for stresses in eccentric, circular hoppers

Abstract

A principal stress cap model for stresses in circular, eccentric hoppers is presented. The model predicts wall stresses and internal stress distributions. The model is an extension of the analytical model for eccentric stresses in circular silos of Matchett (Chemical Engineering Research and Design, 153 (2020), 107–119), and has many things in common with that model. Two stress regimes are predicted: Enstad-Walker stress; and exponential-like stress. The exponential-like stress regime predicts very large stresses towards the apex of the cone, and would aid flow from the hopper. Large variations in wall normal stress are predicted in certain circumstances. A number of model parameters may be adjusted to fit the model to a set of data, related to the shape of the principal stress cap and principal stress ratios. Large sets of data are required to calibrate the model and more experimentation is required, including the measurement of internal stresses, and measurement of several components of the stress tensor.