11. In addition many frame builders file the lugs to thin them, in order to reduce stress concentrations . 12. Another method used to decrease the stress concentration is by creating the fillet at the sharp edges. 13. This indicates stress concentration , possibly the combination of residual stress from forming and the action of the spring. 14. Concepts such as the stress concentration factor and the strain energy release rate can be used to predict failure. 15. However, over time, as the glass expands and contracts, stress concentrations can develop around the nick, leading to breakage. 16. A . W . Griffith took this example and applied the concept of stress concentration to the ends of fractures. 17. Note that the stress concentration factor is a function of the geometry of a crack, and not of its size. 18. To prevent stress concentrations the ends of the splines are chamfered ( as opposed to an abrupt vertical end ). 19. Crack initiation was usually caused either by defects or poor design, with stress concentrations raising the local stress to failure. 20. Ductility is an important factor in ensuring the integrity of structures by enabling them to sustain local stress concentrations without fracture.
