REDESIGN TECHNIQUES FOR IMPROVED STRUCTURAL DYNAMICS

This thesis presents a method for synthesizing design changes which improve the dynamic characteristics of structures by removing natural frequencies from bands where excitations are likely to occur. The procedure, which is less restrictive than traditional techniques, minimizes a penalty function which is large when undesirable frequencies exist, and when design changes are large. A trade-off is found between improved dynamics and undesirably large changes. An example is included in which engine mounts are redesigned to avoid idle speed resonances.