Model Order Reduction - Automated Two-Step Approaches

A two-step model order reduction method is investigated in order to overcome problems of certain one-step methods. Not only optimal combinations of one-step reductions are considered but also the selection of a suitable intermediate dimension is described. Several automated selection methods are presented and their application tested on a gear box model. The implementation is realized using a Matlab-based Software "MORPACK". Several recommendations are given towards the selection of a suitable intermediate dimension, and problems in Model Order Reduction combination are pointed out. A pseudo two-step is suggested to reduce the full system without any modal information. A new node selection approach is proposed to enhance the SEREP approximation of the system's response for small reduced representations.