DESIGN SENSITIVITY METRIC FOR STRUCTURAL DYNAMIC-RESPONSE

An approach to study the sensitivity of dynamic responses for structur al systems with respect to a set of design parameters is presented. Th e sensitivity is evaluated by considering the behavior of the system r esponse when the design parameters vary within a given region of the d esign space. The sensitivity is computed by means of approximate respo nses, which are evaluated using approximation concepts. The approximat ion is based on modal analysis, and it is valid for general underdampe d linear systems. Intermediate design variable and intermediate respon se quantity concepts are used to enhance the accuracy of the approxima tion. In this approach, modal energies and mode shapes are chosen as i ntermediate response quantities, and they are approximated in terms of selected intermediate system parameters. The approximation of these q uantities requires a standard eigenvalue and eigenvector sensitivity a nalysis. Numerical results that illustrate the usefulness and effectiv eness of the method are presented. Great insight into the behavior of the system can be gained using this methodology.