Stress Intensity Factors for Single‐Edge‐Notch Beam

The Strawley equations are commonly used to determine the stress-intensity value for a single-edge-notch beam subjected to three-point, four-point, or pure bending. These equations were derived using assumptions treating the concentrated loads that limited the results to certain ranges of span to depth. A well known method for expressing boundary conditions—the bending analogy—is utilized along with the William's Stress Function to calculate stress-intensity values. This approach requires no special treatment on the boundary in dealing with concentrated loads. This method was applied to determine the influence of the span to depth ratio on stress-intensity values. It was found that the stress-intensity approaches a constant value for a unit midspan moment when the span to depth approaches 12. The present method is very economical to use for any span to depth ratio and three-point or four-point bending. Pure bending and other loadings such as direct tension are handled easily. Results are also presented in the form of engineering equations for K_I for various ratios of span to depth which are accurate within 3% based on least squares.