Reliability-based design optimization of tow-steered composite plates employing high-order CUF-based finite elements

As with every manufactured part, composite structures are affected by manufacturing defects. Indeed, these flaws may arise at any stage of the fabrication chain and are present at the different scales of the composite material. For instance, mesoscale flaws, such as waviness and misalignments, may appear. As a result of these imperfections, the structural response of the final structure might be compromised. Thus, reliability analyses become mandatory. In this work, a reliability-based design optimization (RBDO) concerning the buckling response of a tow-steered laminated plate, including uncertainty at the layer-level, is proposed. The analysis of such structures is conducted by using the Carrera Unified Formulation (CUF). CUF allows obtaining low-order accuracy models up to layer-wise models in a hierarchical and unified manner. Then, surrogate models are built with the outcomes of those analyses, hence alleviating the computational cost of the optimization process. The final scope of the work is to show that layer-wise models can be helpful to broaden the design space that classical structural theories may have shrunk.