The Experimental Modal Craig-Bampton Substructure

Dr. Roy Craig popularized his Craig-Bampton reduced order model that is a widely used substructure in many finite element codes. With this substructure, a small number of fixed base modal DOF can provide quite adequate accuracy for the elastic response of the component with tremendous computational efficiency. Here is a review of an experimental based substructure derived from modal tests that takes advantage of the concept of the fixed base modes. Although derived from experimental measurements, there are significant similarities to Craig’s finite element-based method. In addition, the usefulness of this experimental substructure form is extended to effective mass estimates, predictions for 6 DOF environmental testing effectiveness and component specifications.