Simulating future test and redesign considering epistemic model uncertainty

At the initial design stage engineers oft.en rely onlow-fldelity models that have high epistemic uncertainty. Taditional safety-margin-based deterministic design resorts to testing to reduce epistemic uncertainty and achieve targeted levels of safety. Testing is used to calibrate models and prescribe redesign when tests are not passed. After calibration, reduced epistemic model uncertainty can be leveraged through redesign to restore safety or improve design per for mance; howevet·, redesign may be associated with substantial costs or delays. In this paper, a methodology is described for optimizing the safety-margin-based design, testing, and redesign process to allow the designer· to tradeoff between the risk of future redesign and the possible performance and reliability beneflts. The proposed methodology represents the epistemic model uncertainty with a Kriging sunogate and is applicable in a wide range o f design problems. The method is illustrated on a cantilever bearn design problem where there is mixed epistemic model error and aleatory parameter uncertainty.