EXPERIMENTALLY CHARACTERIZED DYNAMIC STRUCTURES IN AN ANALYTICAL FINITE ELEMENT SOLUTION

摘要

Sometimes when a dynamic finite element model is requested, the entire dynamic system cannot be modeled. How can the dynamic effect of an unmodeled portion of a structure be included in a finite element model? For example, what are the natural frequencies and mode shapes of a battery pack for an electric vehicle when the pack is mounted to the frame of the vehicle? Modeling the battery pack alone in a free-free or fixed-free state may not be indicative of the total system behavior. This paper proposes describes, and illustrates a method for incorporating the dynamic behavior of the adjoining structure in the model by using the concept of modal analysis. This is accomplished by the addition of single degree-of-freedom mass-spring systems which replicate the modal behavior of the attached structure, and by the use of constraint equations to transfer the experimental mode shape information to the model.