A Comparison of Reduced Order Modeling Techniques Used in Dynamic Substructuring

Experimental dynamic substructuring is a means whereby a mathematical model for a substructure can be obtained experimentally and then coupled to a model for the rest of the assembly to predict the response. Recently, several methods have been proposed that use a transmission simulator to overcome sensitivity to measurement errors and to exercise the interface between the substructures. This chapter compares the advantages and disadvantages of multiple reduced order modeling strategies for two dynamic substructuring problems. First, a simple system is investigated using two beams connected by means of a transmission simulator. With this simple system, multiple dynamic substructuring and model reduction techniques are considered including the traditional transmission simulator, Craig–Bampton, dual Craig–Bampton (DCB), Craig–Chang, and Craig–Mayes methods. The second system consists of a beam attached to a plate on one end of a cylinder that encases a pressed foam and metal assembly. This second example uses actual experimental measurements while the beam example is purely a numerical demonstration. By using a finite element model of the beam-plate-can assembly, an experimental model of the dynamics for the internal foam system can be described using dynamic substructuring. This is investigated using the traditional transmission simulator and Craig–Mayes techniques.