Richard G. DeJong
Eng. Dept., Calvin College, 3201 Burton St. S.E., Grand Rapids, MI 49546
Energy concepts are used to develop techniques for optimizing the design and control of structural vibrations. In searching for a design that minimizes the vibrational amplitude of a structure at a number of points and frequencies, the minimization function is very irregular, having many local minima in the design parameter space. This makes it difficult for automated search algorithms to find a global minimum. The use of frequency-averaged energy levels as the response variable provides a smoother minimization function and better results from optimization algorithms. Similarly, in active control systems, the use of measured point vibration amplitudes as the minimization function suffers when the measured points correspond to the nodes in a modal response. The use of structural intensity measurements as the minimization function helps to overcome this problem. Several examples are given for beam and plate structures.