Extended constitutive relation error‐based approach: The role of mass in damage detection

Abstract

This paper presents an extended constitutive relation error (ECRE)-based method for detecting damage in structural systems. Although most ECRE-based methods for damage detection have relied on an iterative model calibration process, the approach advocated in this study uses residual energy to identify structural damage. Residual energy represents the spatial distribution of discrepancies between model predictions of the undamaged system and experimental measurements obtained from the damaged system. The current study calculates this residual energy by tightly linking experimentally measured vibration data to an associated numerical model. The approach implemented in this paper, referred to as the M-K ECRE-based approach, differs from previous ECRE-based damage detection methods in that it incorporates both unbalanced elastic and unbalanced inertial forces in the calculation of residual energy. The rationale for including unbalanced inertial forces is that damage can also alter the mass distribution of a structure in addition to its influence on the distribution of structural stiffness. By considering unbalanced inertial forces, the proposed approach improves the calculation of residual energy, which in turn leads to an improvement in the method's ability to identify damage. At the end of this study, the efficiency of the M-K ECRE-based approach to identify damage is demonstrated on a scaled two-story steel frame that is subjected to varying types and severities of structural damage.