APPROACH OF DAMAGE IDENTIFICATION BASED ON STIFINESS CHANGE RATIO BY NEUMANN SERIES EXPANSION

Abstract

A direct solution procedure for structural damage identification based on stiffness change ratio was proposed.Utilized with Neumann series expansion,the damaged structural stiffness change ratio matrix was derived,in a form of matrix product. The stiffness loss of the damaged element was treated as accessional dummy stiffness,and then the extent of element damage obtained by transformations of stiffness change ratio matrix. The method contributes a concise expression and higher computational efficiency. Numerical simulation example of a 3D aircraft wing frame model was performed via the proposed method,and the influence of test noise and incomplete test modal was considered,the results show that the identified values are accurate and stable.

Keywords

• Damage identification;Damage index;Modal flexibility;Neumann series expansion