Multiparameter Design Optimisation in Respect of Stress Concentrations

The dependence of stress concentrations (structural stress, notch stress and crack stress intensity) on the dimension ratios in the structure under review, can be presented within delineated dimension areas as a simple approximation formula. The dimension ratios occur multiplicatively in this formula, with initially unknown exponents (smaller than one). The exponents can be determined from a small number of supporting point values of the stress concentration. They indicate to the designer the dimension ratios to which the stress concentration reacts particularly “sensitively”, the direction in which this occurs and how large the possible reduction is. On the other hand, it becomes clear which dimension ratios have no or little influence on the stress concentration. The designer is thus provided with a valuable aid for structural optimisation. The method is demonstrated by way of example for the notch stress concentrations of welded cruciform joints.