A Study on Damage Detection in Continuum Structures by Plastic
System Identification Technique with Static Responses
H.W. Park, H.S. Lee
ABSTRACT
The paper presents a system identification scheme based on elasto-plastic behaviors of solids for damage detection in continuous structures. The proposed algorithm is based on the minimization of the least squared errors between the measured displacement field and calculated displacement field by a finite element model. The initial yield stresses of finite elements are selected as system parameters. An adaptive parameter grouping scheme is employed to overcome the sparseness of the measurement data. The constitutive relation of an elasto-plastic material is linearized by the consistent tangent moduli. The first-order sensitivity of displacement is calculated by the direct differentiation of the variational statement of the equation of motion. The recursive quadratic programming technique with Fletcher's active set algorithm is adopted for optimization. Two examples are presented to de-monstrate the validity of the proposed method, and to compare results by the proposed plastic SI with those by elastic SI.
KEY WORDS : damage detection, elasto-plastic behavior, continuous structure, plastic SI, elastic SI, adaptive parameter grouping scheme, optimization , consistent tangent moduli, direct differentiationIf you need full text, please visit http://www.dbpia.co.kr