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We consider the scattering of in-plane waves that interact with an edge of a structured penetrable inertial line defect contained in a triangular lattice, composed of periodically placed masses interconnected by massless elastic rods. The steady state problem for a time-harmonic excitation is converted into a vector Wiener–Hopf equation using the Fourier transform. The matrix Wiener–Hopf kernel of this equation describes the dynamic phenomena engaged in the scattering process, which includes instances where localised interfacial waves can emerge along the structured defect. This information is exploited to identify the dependency of the existence of these waves on the incident wave parameters and the properties of inertial defect. Symmetry in the structure of the scattering medium allows us to convert the vectorial problem into a pair of uncoupled scalar Wiener–Hopf equations posed along the lattice row containing the defect. The solution embodies an exact representation of the scattered field, in terms of a contour integral in the complex plane, that includes the contributions of evanescent and propagating waves. The solution reveals that in the remote lattice, the reflected and transmitted components of incident field are accompanied by dynamic modes from three symmetry classes, which include localised interfacial waves. These classes correspond to tensile modes acting transverse to the defected lattice row, shear modes that act parallel to this row, and wave modes represented as a mixture of these two responses. Benchmark finite element calculations are also provided to validate the results against our semi-analytical solution which involves, in particular, numerical computation of the contour integrals. Graphical illustrations demonstrate special dynamic responses encountered during the wave scattering process, including dynamic anisotropy, negative reflection and negative refraction. • In-plane wave scattering by a structured inertial defect in a triangular lattice is studied. • The analytical solution for the scattered field is obtained via an application of the Wiener–Hopf technique. • Remote wave modes are classified by the fundamental mechanical symmetries they possess. • Special bulk dynamic responses engaged in the scattering process are discussed. • Pass band for the interfacial waves supported by the inertial defect are obtained. [ABSTRACT FROM AUTHOR]

Abstract The ability to analyse attenuation rates of individual wave fields along rough media using the effective wave field is investigated for the problem of a string with continuous, randomly varying properties. A clustering method is developed to approximate the continuous problem as a discrete problem, which provides insights into the relationship between the effective and individual wave fields. It is found that as scattering strength increases the attenuation rate of the effective wave field experiences a rapid transition from being orders of magnitude greater than the attenuation rate of its constituent individual wave fields to being almost identical to it. Highlights • Wave attenuation along rough string with continuous wavenumber variations studied. • Effective wave fields and individual wave fields compared. • Scattering strength/roughness amplitude controls agreement of attenuation rates. • Sharp transition of agreement as scattering strength/roughness amplitude increases. [ABSTRACT FROM AUTHOR]

The paper presents a novel analysis of localisation and transmission properties of randomly-perturbed flexural systems. Attention is given to the study of propagation regimes and the connection with transmission resonances following perturbations of ordered stacks. The analytical study is complemented with numerical simulations relevant to different discrete systems. Applications are in the design of efficient vibration isolation systems and filters of elastic waves considered as ordered structures subjected to small random perturbations. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this paper is to investigate the role of microscale inertia in dynamic ductile crack growth. A constitutive model for porous solids that accounts for dynamic effects due to void growth is proposed. The model has been implemented in a finite element code and simulations of crack growth in a notched bar and in an edge cracked specimen have been performed. Results are compared to predictions obtained via the Gurson–Tvergaard–Needleman (GTN) model where micro-inertia effects are not accounted for. It is found that microscale inertia has a significant influence on the crack growth. In particular, it is shown that micro-inertia plays an important role during the strain localisation process by impeding void growth. Therefore, the resulting damage accumulation occurs in a more progressive manner. For this reason, simulations based on the proposed modelling exhibit much less mesh sensitivity than those based on the viscoplastic GTN model. Microscale inertia is also found to lead to lower crack speeds. Effects of micro-inertia on fracture toughness are evaluated. [Copyright &y& Elsevier]

Demand for data centre services in Russia is set to skyrocket in 2015 after the Russian government brought forward the deadline for compliance to its Localisation Law by a year. [ABSTRACT FROM AUTHOR]

Level 3 Communications has reached an agreement with Telekom Malaysia (TM) to provide internet localisation services. [ABSTRACT FROM AUTHOR]