A NEW MODIFICATION METHOD FOR STRUCTURAL DYNAMIC CHARACTERISTICS

This article presents a new modification method for the structural dynamic characteristics. The modification procedure is to reset the natural frequency of the original structure by adding the structural mass and stiffness Upon the completion of the modification, the dynamic characteristics of modified structures is satisfactory accrording to the design requirements The method adopts the cross-model cross-mode (CMCM) method originally developed for model updating, with the complete modal data replaced by the target frequencies. Numerical example is given for a five-degree-of-freedom spring-mass system. Several scenarios are studied including resetting single frequency and muti-frequency. Numerical results indicate the modifaction method is applicable to the modification of structural frequency.