Ship Structure Optimization Using CAD/FEM Integration

In ship structural design, scantling optimization using mathematical algorithms is not yet largely
implemented in industry. Optimization with mathematical algorithms can be very helpful to find the best
solution (minimum weight, minimum cost, maximum inertia,…). Typically, finite element analysis (FEA)
tools are used in ship structural assessment. But, to build a FEM model from a CAD one is not easy. It
needs a big amount of manual work. In the present work, an innovative optimization workflow was
developed. The following steps are carried automatically without any manual intervention. First, from
the 3D CAD model, an idealized CAD model is created by the idealization module to take into account
the FEM needs. Then, the idealized CAD model is transferred to the FEM tool. After that, the FEM
model is meshed and loaded. After FEM solving, the results (stress, displacement, volume etc.) are
transferred to the optimizer. The optimizer evaluates the values of the objective function and the
constraints previously defined and modify the design variables (plate thickness and the stiffener
scantling) to create a new structural model. After several iterations, the optimum solution is evaluated.