Selection of optimal artificial boundary condition (ABC) frequencies for structural damage identification

Abstract

In this paper, the sensitivities of artificial boundary condition (ABC) frequencies to the damages are investigated, and the optimal sensors are selected to provide the reliable structural damage identification. The sensitivity expressions for one-pin and two-pin ABC frequencies, which are the natural frequencies from structures with one and two additional constraints to its original boundary condition, respectively, are proposed. Based on the expressions, the contributions of the underlying mode shapes in the ABC frequencies can be calculated and used to select more sensitive ABC frequencies. Selection criteria are then defined for different conditions, and their performance in structural damage identification is examined with numerical studies. From the findings, conclusions are given.

Experimental study of sensitivity-aided application of artificial boundary condition frequencies for damage identification

“…In this section, an overview of the theoretical formulation for the sensitivity of ABC frequencies is provided. In particular, the sensitivity of two-pin ABC frequencies and the underlying mode shape contribution [26] are discussed in connection with the selection of ABC frequencies for damage identification.…”

“…The similar line of formulation can be extended to the sensitivity of two-pin ABC frequencies and the determination of the mode shape contributions in the two-pin ABC frequency sensitivities, as discussed in detail in [26]. Let the measured 2 2  FRF matrix be expressed as:…”

“…As mentioned earlier, there exists a large amount of ABC pin configurations, especially in two-pin scenarios, it is necessary to make a selection from all available one-pin and two-pin ABC frequencies to achieve better identification results. In this section, the selection scheme proposed in [26] is used for the ABC frequency selection, which can be briefly described below.…”

“…the ABC pin supports, may be configured for the ABC frequencies, the inherent information with the ABC frequencies requires further investigation so that more suitable ABC frequencies can be selected to ensure better identification performance. However, only limited research in the literature has been devoted to the selection of ABC frequency for damage identification [23,26].…”

Damage Detection of Laminated Rubber Bearings Based on the Antiresonance Frequencies of Periodic Structure and Its Sensitivity Analysis

“…e first method is to extract data from the frequency response or impedance curve [23][24][25][26], which are the zeros of the curves. e other method is to calculate the eigenvalues of a structure under a variety of artificial constraints applied to the ground combined with transducer location data [28,29]. A set of sensitivities of antiresonance frequencies [28] was used for damage identification.…”