Stresses near the edges of ring‐loaded plates

Abstract Strength testing of brittle materials often employs beams or plates loaded in bending. Solutions are provided for the in‐plane stresses between the support ring and edge of ring‐loaded circular plates (i.e., disks) having a diameter larger than the support ring. The region overhanging the larger support ring stiffens the plate and reduces the edge tangential stress. Its consideration is thus crucial to an accurate solution. For typical ceramic disks with little overhang, the edge stress is less than ~50% of the maximum, central stress. With a large overhang, the edge stress can be reduced to ~25% of the central stress. The radial stress reverses the sign outside the support ring, whereas that of the tangential stress remains the same, and thus tensile failure can occur from either face of the disk.