PSI - Issue 82

Victor Rizov et al. / Procedia Structural Integrity 82 (2026) 253–259 V. Rizov/ Structural Integrity Procedia 00 (2026) 000–000

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multilayered materials in the current engineering puts raised requirements with respect to various aspects of their mechanical behavior under different loadings (Lloyd and Molina-Aldareguia (2003), Rizov (2018), Rzhanitsyn (1986)). The layered structure of these materials makes delamination fracture one of the basic causes for failure of multilayered engineering constructions (Dolgov (2005), Dowling (2007), Rizov (2018), Rizov (2019)). Therefore, accumulation of knowledge about the delamination behavior of the members of various multilayered constructions is an important issue. This knowledge may have a key role for safety and stability of constructions. The present paper studies analytically two symmetric delaminations in a double clamped column under subsidence of the lower end. The column has viscoelastic behavior. The two delamination cracks are located symmetrically with respect to the column axis. The column is made of three layers which are continuously inhomogeneous in longitudinal direction (use of continuously inhomogeneous materials is a subject of intense studies in the engineering community (Gasik (2010), Mahamood and Akinlabi (2017), Radhika et al. (2020), Toudehdehghan et al. (2017)). The SERR for the two delamination cracks is determined. For this purpose, the mechanical response of the column to the support subsidence is analyzed with the help of the equilibrium equations. The SERR is checked-up by analyzing the strain energy stored in the column as a result of the support subsidence. Parametric analysis of the SERR is done and the findings are shown in graphic form. 2. Theoretical analysis The column in Fig. 1 is double clamped.

Fig. 1. Column with two symmetric delaminations.

The two parts of the column, , the column has three layers. The outer layers have the same thickness and are made of identical structural materials. Two delaminations are located between layers in part, , of the column (Fig. 1). The column is subjected to subsidence, , of its " ! !! " ! ! ! " ! !! " ! ! ! ! ! " and , have different thickness. In part,