About the Two Hole (Relief Notch) Example

This example uses the principle of a relief notch and demonstrates how the optimization task should be defined.

This page discusses:

About the Model

High stresses are found in a notch (primary notch) of a component. A second notch (secondary notch) having a short distance to the primary notch should work to relieve the stresses on the primary notch. The optimal shape of the secondary notch should be obtained using shape optimization to achieve as low a stress factor as possible in the primary notch:



The stress in the primary notch is only minimal when the maximum stresses in the secondary notch and the primary notch are the same. A distribution of the notch effect takes place at both positions. To optimize this effect, a definition must be made using a variable reference value. The definition of following groups is required for the optimization task:



Procedure Summary

Model: twohole.ext
Design Area: Node group design_nodes
Design Variable Constraint: Solid body boundaries for the design nodes
Design Variable Constraint: Fixation of the displacement along the global y-axis for the node group fix_y
Mesh Smooth: Mesh smoothing of element group ms_elgr, while free surface nodes remain free
Objective: Minimize the deviation of the maximal von Mises stresses in the primary and secondary notch
Settings: Average nodal displacement, nodal displacements are scaled by factor 2 additionally
Stop Condition The global stop condition is set to ten iterations