Elements of Measurement Using the Slitting Method
- 1.1k Downloads
All mechanical methods of residual stress measurement are based on the principles of elasticity and linear superposition. In particular, the superposition for the slitting method as shown in Fig. 2.1, is extended from Bueckner’s principle for crack propagation . When a cut of depth a is introduced to a part with residual stress (case A), the stress on the site of cut is released (case B). This process is the same as imposing a stress field of the same magnitude of the stress in (case A) with a different sign on the site of the cut (case C), which leads to a stress-free slit face in case B. To compute the deformation or the compliance functions due to introduction of the cut in case B, we make use of case C because there is no change in deformation in case A. Note the superposition shown in Fig. 2.1 remains valid when external loads are present. For a body with prescribed displacement boundary conditions, however, the boundary condition should be properly maintained, as shown in Fig. 2.2. Note that the displacement at the boundary for case C should be set to zero. The stress estimated from the deformation measured from case B and the compliance functions computed from case C is due to both the residual stress and the prescribed boundary condition in case A.
KeywordsResidual Stress Electric Discharge Machine Wire Electric Discharge Machine Linear Superposition Residual Stress Measurement
Unable to display preview. Download preview PDF.