Structural Damage Detection Using Auto/Cross-Correlation Functions Under Multiple Unknown Excitations

Abstract

Traditional structural system identification and damage detection methods use vibration responses under single excitation. This paper presents an auto/cross-correlation function-based method using acceleration responses under multiple ambient white noise or impact excitations. The auto/cross-correlation functions are divided into two parts. One is associated with the structural parameters and the other with the energy of the excitation. These two parts are updated sequentially using a two-stage method. Numerical and experimental studies are conducted to demonstrate the accuracy and robustness of the proposed method. The effects of measurement noise and number of measurement points on the identification results are also studied.

Finite element model updating using strain-based power spectral density for damage detection

“…The statistical properties of the structural response excited by random excitation such as ambient white noise have proven to be potentially applicable for SHM and parameter identification purposes [30,31]. These properties are more important for kind of structures that are normally operating in random environment.…”

Study on an auto-correlation-function-based damage index: Sensitivity analysis and structural damage detection

“…As the sensitivity of the normalized AMV to the local stiffness ηðR AMV =k j Þ has the expression in Eq. (29), only the lower order modal parameters will affect the value of ηðR AMV =k j Þ. Therefore, only the sensitivity of Ψ 11 Ψ 1 , Ψ 11 Ψ 2 and Ψ 21 Ψ 2 to the local stiffness k j is considered here.…”

“…(29), the value of ηðR AMV =k j Þ is related to the sensitivity of the Hadamard product of mode shapes to the local stiffness k j , i.e. η½ðΨ r 1 Ψ s Þ=k j , the sensitivity of μ rs to the local stiffness k j , i.e.…”

“…Afterwards they used the matrix of the covariance of covariance, which is also obtained by the auto/cross correlation function of acceleration response signals under white noise excitation, successfully detected the damages of a simply supported plane truss structure [28]. Ni and Xia [29] found the auto/cross correlation function can be divided into two parts, one is associated with the modal parameters and the other with the excitation. They used a two-stage method updated these two parts for detecting the damage under multiple unknown excitations numerically and experimentally.…”

Method of shaft crack detection based on squared gain of vibration amplitude

“…They were able to identify a fault signature in the planet's tooth even in a case when the amount of the available stationary vibration data was limited. Ni et al [42] considered auto-/crosscorrelation functions of multiple excitations applied to a mechanical structure. The functions were divided into two parts: the time-variant one associated with unit response functions depending on structural parameters, and the time-invariant one depending on the energy of the excitation force.…”