Dynamic stability analysis of reduced delaminated planar beam structures using extended Craig-Bampton method

Abstract

In this article the dynamic buckling behaviour of parametrically excited delaminated composite beam structures are investigated using a two-dimensional finite element discretised planar model. To reduce the complexity of the numerical model and to be able to maintain the desired accuracy of the whole system the so called Craig-Bampton fixed interface model reduction technique is extended. The main concept is to take the vibration and buckling properties of the elastic structure into account during the dynamic stability calculations. Using the extended model reduction technique and the primal assembly technique the reduced model of the planar delaminated beam is created. On the reduced assembly the effect of the number of kept mode shapes, the delamination length and position are investigated on the natural frequencies and critical buckling forces. A similar set of parametric analysis is carried out to study the dynamic stability properties of the reduced delaminated beam structures using Bolotin’s harmonic balance method. Based on our findings we propose an optimal number of kept mode shapes on each reduced substructure during the dynamic stability analysis to reach the desired accuracy on the space of the investigated parameters.