Multi-objective design optimization of variable ribs composite grid plates

Grid structures are among the most lightweight elements for stiffening the plates and shells or as self-sufficient structures. There are different known grid patterns, which are composed of variable numbers of parallel ribs. Selecting an optimum pattern and geometries for a grid to achieve the minimum weight and maximum load-bearing capacity is a challenging procedure for designers. In the current study, a variable ribs model (VRM) is proposed to find the optimum architecture of a grid plate. Therefore, using a genetic algorithm process, a multi-objective optimization is implemented to maximize the axial or shear buckling loads at a minimum possible weight of a grid structure. Eleven geometrical parameters including thickness, width, and the number of ribs as well as the orientation of the grid plate are considered the design variables. The multi-objective optimization is carried out employing the epsilon-constraint method. The buckling loads are obtained based on the first-order shear deformation plate theory using the Ritz method.

Automated summary

Grid structures are lightweight elements used for stiffening plates and shells, with designers facing the challenge of selecting the optimum pattern and geometries to achieve minimum weight and maximum load-bearing capacity. A multi-objective optimization process using a variable ribs model and genetic algorithm is implemented to maximize buckling loads while minimizing weight in grid structures. The optimization considers eleven geometrical parameters and employs the epsilon-constraint method, with buckling loads calculated based on the first-order shear deformation plate theory using the Ritz method.