Dynamic characterization of a system with degradation: A masonry wall. (July 2021)

• Record Type: Journal Article
• Authors: Gatta, C.; Vestroni, F.; Addessi, D.
• Is Part Of: Mechanical systems and signal processing. Volume 156(2021)
• Publication Date: 2021-07
• Subjects: Frequency response curves -- Degrading systems -- Masonry wall -- Dynamic response -- Experimental tests; 00-01 -- 99-00; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2021.107629
• Languages: English
• ISSNs: 0888-3270

Abstract

Highlights: Dynamic characterization of systems with degrading restoring force is dealt with. A masonry wall is adopted as model of real damaging structural elements. Masonry nonlinear response is described with a macromechanical damage-plastic model. Results of shaking table tests are used to prove model reliability. Peculiar features of the frequency response curves due to damage are discussed. Abstract: Characterization of the dynamic behavior of linear systems is exhaustively described with a single frequency response curve ( frc ). For nonlinear systems, which tend to depend on load amplitude, at least one frc for each excitation intensity is required to detect the main characteristics of the dynamic response. Nonlinear systems, more commonly dealt with in the literature, are invariant with respect to the deformation history and, thus, frcs obtained with increasing and decreasing driving frequency coincide, apart from the frequency range with coexistent solutions. This is not so for many real systems which suffer from their past, often exhibiting degradation of their mechanical properties. Here the focus is on the effects of damage on the dynamic signature of systems. The response of a masonry wall, representative of systems with a degrading restoring force, is analyzed under harmonic excitation. A refined finite element model is used to represent the typical degradation that occurs in masonry and its reliability is proved by comparing numerical results and experimental outcomes from shaking table tests. Particular attention is paid to the wall frcs, emphasizing the influence of the deformation history on the curves characteristics and their role in the dynamic characterization of a system with degradation.