On average stress within sub-regions of granular media

The paper concerns computation of average stress within small sub-regions of a larger static granular assembly, where the sub-region’s boundary is allowed to pass through the assembly’s particles. An exact average is computed for certain stress components and for certain categories of sub-regions. The paper also identifies those choices of sub-regions for which exact stress components may be exactly computed, but when these conditions are not met, provides reasonable bounds on the error.