Analytical study on stress intensity factor due to the propagation of Griffith crack in a crystalline monoclinic layer subjected to punch pressure

摘要

An analytical model is introduced to analyse moving Griffith crack in a mono-clinic crystalline layer of finite width and infinite extent with moving parallel punch pressure acting at the bounding surface of the layer because of the propagation of plane waves under mechanical point loading. Formulation of the model includes coupled singular integral equations with Cauchy-type singularities. The expression of stress intensity factor (SIF) at the tip of moving crack having constant point loading is established in the closed-form by employing Hilbert transformation. Further, expression of SIF is deduced for some particular cases of the crystalline layer, that is, without punch pressure and anisot-ropy. For the sake of validation, the obtained results are matched with pre-established and standard results. Numerical computations and graphical demonstrations have been carried out for crystalline materials with monoclinic symmetry like lithium niobate and lithium tantalate and for isotropic material as well to unravel the effect of punch pressure, crack length, distinct positions of acting point load and the velocity of crack on SIF. Further, influence of anisotropy has been traced out remarkably through comparative study that is one of the pinnacles of the present study.