EVOLUTIONARY OPTIMIZATION OF MAXIMIZING THE DIFFERENCE BETWEEN 2 NATURAL FREQUENCIES OF A VIBRATING STRUCTURE

This paper deals with the evolutionary optimization of maximizing the difference between two natural frequencies of a vibrating structure. T wo new criteria, namely the material efficiency criterion and the smoo th change criterion, are derived for solving this kind of evolutionary optimization problem. Using these two new criteria, the evolutionary optimization method has been further extended and applied to maximize the difference between tile fundamental and the second natural frequen cies of a structure under both plane stress and thin plate flexural be nding conditions. The related results demonstrated that the extended e volutionary structural optimization method is useful in and applicable to dealing with the evolutionary optimization of maximizing the diffe rence between two natural frequencies of a vibrating structure. Moreov er, the results also indicated that owing to the different mechanism b etween plane stress and thin plate flexural bending conditions. the op timal topologies, the normalized difference between two natural freque ncies and the normalized material efficiency are different for a vibra ting structure under these two different situations.