Optimization of a Slot End Configuration in a Finite Plate Subjected to Uniformly Distributed Load

Two-dimensional photoelasticity is used to determine the distribution of stresses at the ends of a transverse slot symmetrically located in the uniform field of a thin birefringent strip subjected to tension. The ends of the slot are ellipses with different axes ratios, ranging from a flat ellipse to a semicircle. The stress-concentration factors are found for different ratios of the transverse width of the slot to the total width of the tensile specimen. Optimum shapes are given for each ratio of the transverse width of the slot to the total width of the tensile specimen. The results obtained may prove useful in the design of solid propellant grains.