Remarks on impact of irregularity on SH-type wave propagation in micropolar elastic composite structure

• Published in: International journal of mechanical sciences 2018-01, Vol.135, p.325-341
• Main Authors: Singh, Abhishek Kumar, Chaki, Mriganka Shekhar, Chattopadhyay, Amares
• Format: Article
• Language: English
• Subjects: Dispersion equation; Irregularity; Micropolar elasticity; Perturbation technique; SH-type wave
• ISSN: 0020-7403; 1879-2162
• DOI: 10.1016/j.ijmecsci.2017.11.032

•In the study micropolar layer and half-space with irregular interface is considered.•SH-type & new type of surface wave propagation studied for this composite structure.•Dispersion relations in closed-form are obtained analytically in distinct cases.•It is proved that new type of surface wave propagation is independent of irregularity.•The effect of micropolarity and irregularity have also been revealed numerically. [Display omitted] The present study investigates the propagation characteristics of SH-type wave and a new type of dispersive surface wave in an irregular composite structure comprised of a layer overlying a half-space, both constituted by distinct homogeneous micropolar isotropic elastic materials. At the common interface of the composite structure, two types of irregularities viz. rectangular and parabolic shaped, are studied in two distinct cases. Closed-form of frequency equations of SH-type wave associated with these cases have been obtained and matched with the classical Love wave equation in the isotropic case of the composite structure without irregularity at the common interface. Existence of new type of dispersive surface wave along with its dispersion relation has been deduced in the closed-form by adopting a distinct mathematical treatment for various cases concerned with the presence and absence of microrotational components in the composite structure. It is also examined that the dispersion equation of new type of dispersive surface wave vanishes identically in isotropic case of the composite structure. To unravel the effect of irregularity at the common interface and micropolarity associated with micropolar composite structure on SH-type and new type of dispersive surface wave, numerical computation and graphical demonstrations have been carried out in a comparative manner which serves as a salient feature of the study.