A bi-level meta-modeling approach for structural optimization using modified POD bases and Diffuse Approximation

► A two-stage POD-based meta-model for structural optimization problems. ► A projector that gives a POD basis conserving linear constraints by design. ► Modified the POD coefficients to conserve quadratic constraints. ► Comparison with the traditional POD for two test-cases. ► Head injury criterion and performance of an air-conditioning duct.