Intrinsic Damping: Modeling Techniques for Engineering Systems

Mathematical models for capturing the effects of intrinsic damping are based upon a multitude of simplifying assumptions. In this work, common equivalent linear models are reviewed, and their implementations for modeling energy dissipation on the system and material scales are compared in simple, representative examples. It is shown that several independent methodologies result in approximately the same predicted responses for systems with uniform dissipative characteristics if certain assumptions are made regarding the frequency dependence of intrinsic damping. However, these assumptions result in divergences of predicted responses when extended to composite systems with nonuniform dissipative characteristics. As no analytical or validated numerical solutions for the dynamic response of composite systems with nonuniform dissipative characteristics exist, it is unclear as to which methodologies most closely predict composite system behavior. Further work in developing models to capture nonuniform intrinsic damping characteristics must be performed to generate a fully robust means for capturing energy dissipation across all levels of complexity in engineering systems.