31. The tool path and normal pressure applied are designed to create a distribution of compressive residual stress . 32. Also, the distorted grain structure that gives the workpiece its superior strength can lead to residual stresses . 33. Residual stress may be desirable or undesirable.34. This indicates stress concentration, possibly the combination of residual stress from forming and the action of the spring. 35. If there is residual stress within the polymer, the piece will shrink when held at such a temperature. 36. The deformations are related to the residual stress in the volume of material that was removed through drilling. 37. Residual stresses are measured through experiments.38. As these interstitial atoms distort the lattice slightly, there will be an associated residual stress field surrounding the interstitial. 39. The evaluation of the residual stresses depends on the method used to calculate them from the measured relieved deformations. 40. In 1966 Rendler and Vignis introduced a systematic and repeatable procedure of hole drilling to measure the residual stress .
