- Look up the expected stress concentration for a stepped bar without a fillet, i.e., a discontinuity in the cross-sectional area. Using one-dimensional link or bar elements, create a one-dimensional mesh for the stepped shaft using elements with different cross-sectional areas. Note predictions for the stress in the vicinity of the discontinuity at the sharp re-entrant corner. What do you notice?
- Refine the mesh in the vicinity of the step and report your results for the stress variation across the step. What conclusion might you draw from this exercise?
Re-run the SimCafe tutorial refining the two-dimensional axisymmetric mesh in the vicinity of the fillet. Using h-convergence mesh refinement, optimize the ratio of element edge length to fillet radius, i.e., determine the ratio of element edge length to fillet radius that will result in a converged solution for the stress concentration to within the accuracy of the reported formula (5%).
Using an axisymmetric model (as opposed to a full three-dimensional model), qualitatively confirm the relaxation of the stress concentration illustrated in Figure 3.4 of the text.