| Residual stresses are stress fields that prevail in non-loaded structures. |
Residual stresses are stress fields that prevail in non-loaded structures. |
| For instance, a normal bolt resting in the palm of your hand may experience large measures of stress. |
For instance, a normal bolt resting in the palm of your hand may experience large measures of stress. |
| This is not because of your demeanor or the way you are holding it, instead it is due to the way the bolt has been manufactured. |
This is not because of your demeanor or the way you are holding it, instead it is due to the way the bolt has been manufactured. |
| A quality thread is rolled rather than cut. |
A quality thread is rolled rather than cut. |
| Thus the material has been subjected to significant plastic deformation, which creates compressive stresses in the creases of the thread. |
Thus the material has been subjected to significant plastic deformation, which creates compressive stresses in the creases of the thread. |
| The treatment also generates tensile stresses, as required by the law of force equilibrium. |
The treatment also generates tensile stresses, as required by the law of force equilibrium. |
| Compressive residual stresses in the thread are favorable to the fatigue life of the bolt, and are thus desirable. |
Compressive residual stresses in the thread are favorable to the fatigue life of the bolt, and are thus desirable. |
| The corresponding tensile stress's, on the other hand, may have a negative impact on the maximum load carrying capacity. |
The corresponding tensile stress's, on the other hand, may have a negative impact on the maximum load carrying capacity. |
| However, this weakening effect is small thanks to the material's ability to yield and redistribute the stress fields in the event of an extreme load. |
However, this weakening effect is small thanks to the material's ability to yield and redistribute the stress fields in the event of an extreme load. |
| Residual stresses may have positive, negative or no practical effects on a structure's mechanical integrity. |
Residual stresses may have positive, negative or no practical effects on a structure's mechanical integrity. |
| Whatever the case may be, knowing about them is important. |
Whatever the case may be, knowing about them is important. |
| This chapter explains common causes and possible effects of residual stresses, and thoroughly prepares the reader for related topics in subsequent chapters. |
This chapter explains common causes and possible effects of residual stresses, and thoroughly prepares the reader for related topics in subsequent chapters. |
