A modal derivatives enhanced Craig-Bampton method for geometrically nonlinear structural dynamics

Abstract

Component Mode Synthesis is commonly used to simulate the structural behavior of complex systems with many degrees of freedom. The Craig-Bampton approach is one of the most commonly used techniques. A novel reduction method is proposed here for geometrically nonlinear models by augmenting the constraint modes and internal vibration modes with the modal derivatives. A subset of the corresponding modal derivatives can therefore be efficiently used to consider the geometric nonlinearities. This modal substructuring technique is an extension of the Craig-Bampton method without increasing the difficulty of implementation. The applicability and efficiency of the modal derivative based Craig-Bampton method for nonlinear system is demonstrated by a numerical example.