Topological optimization design of 3×3 grid stiffened panel with additional damping layers based on evolutionary structural optimization

The topological optimization design of a 3×3 grid stiffened panel was conducted using the Evolutionary Structural Optimization (ESO) method with the amount of constrained damping layers as a constraint condition, and the maximization of modal loss factor as a target function. The optimization was completed by using a self-coded C program based on ESO method, and by applying the ABAQUS software to model the structure. The results show that along with the increase of the removal ratio of constrianed damping layers, the modal damping loss factor of the compound 3×3 grid stiffened panel remains unchanged at first, then increases to its maximum value and thereafter gradually decreases. Moreover, normalized first modal loss factor of the 3×3 grid stiffened panel with specialized additional damping layers becomes bigger and bigger, which shows that the additional damping layers in the middle portion of the panel contribute much to the suppressing of structural vibration. The Mises stress distribution contours and the maximum Mises stresses of the structures with 0%, 50%, 100% volume amount of constrained damping layers were compared in order to study the optimal layout of the 3×3 grid stiffened panel in resonance conditions. The results show that the optimal layout, with 50% volume amount of constrained damping layer, has little effect on the Mises stress distribution but the maximum Mises stress decreases obviously. The method has been also used in the optimization design of general complex structures to reach the aim of mass reduction with a little sacrifice in damping effect, which can be widely used in optimization design of general damping structures. The method is of great practicability.