Direct identification of non-uniform beams using static strains

method for identifying the flexural rigidities of a non-uniform beam is developed in this paper. The finite element method is used to derive the equilibrium equation of the beam. The identification problem is then formulated as an optimization program in which the error norm of the equilibrium equation is minimized. The proposed method has the following features : (1) it uses longitudinal strains as the primary test data ; (2) the solution is unique and global minimal ; (3) the method can be applied to a whole beam as well as a part of a beam ; (4) the method is very stable. The identifiability of the inverse problem is studied in depth. Two numerical examples are presented to demonstrate the proposed method. Finally, a model test is performed to examine the effectiveness of the method in real applications, Copyright 0 1996 Elsevier Science Ltd.