PSI - Issue 68

Oleh Yashiy et al. / Procedia Structural Integrity 68 (2025) 126–131 O. Yashiy et al. / Structural Integrity Procedia 00 (2025) 000–000

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The same considerations can be applied to the analysis of fracture in the vicinity of the inclusion tip. However, due to the complexity of the resulting equations, their explicit form is not presented within this work. The fracture behavior near the tip of the inclusion involves intricate stress distributions and singularities, making the mathematical treatment more involved. These equations require a more detailed analysis and will be addressed in future studies or in a separate work, where the complexity of the interactions between the inclusion and the surrounding material can be explored more thoroughly. Consider an isotropic thermoelastic medium with a Poisson’s ratio of containing a rectilinear, deformable thread-like inclusion of length . A uniform heat flux with intensity is applied parallel to the axis of the inclusion. It is important to note that there are no heat sources present within the inhomogeneity. Consider the influence of the normalized relative thermal resistance , compliance , and thermal expansion on the debonding fracture parameter (see Eq. (12)) !"# ! = ! ! ! ! ( ) ( ) ! ! " ! ! " # " ! "# = ( ) ( ) ! ! " ! " ! µ "# = ! ! ! ! = !

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Here is the linear thermal expansion coefficient. The superscript “i” corresponds to the parameters associated with the inhomogeneity. Fig. 1 shows the normalized value of for and different values of nondimensional relative thermal resistance and compliance of the thread-like inhomogeneity. It is assumed that . ! " µ ! ! ( ) ! " # # $ ! " " # $ % ! µ = ! ! = ! ! ! "# ! ! " = is the heat conduction coefficient, is the shear modulus, is the elastic modulus, and

Fig. 1. Debonding fracture parameter for a thread-like inhomogeneity.

It can be observed that the debonding fracture parameter increases. This indicates that the more compliant the thread-like inclusion is, the lower its susceptibility to debonding. In other words, a thread with greater flexibility can better accommodate the stresses and strains imposed by the surrounding material, thereby reducing the risk of fracture at the interface. On the other hand, the thermal resistance of the inhomogeneity has a relatively minor influence on the debonding fracture parameter . As the thermal resistance increases, the debonding fracture parameter tends to increase as ! ! ! decreases as

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