The scattered field arising from diffraction of a plane flexural wave by a semi-infinite crack in an orthotropic Kirchhoff thin plate is analysed. The crack is aligned with a principal direction of the material, so that two of the plate’s three planes of symmetry are preserved. An asymptotic approximation is derived via the method of steepest descents, and explicit expressions are given for the...

It is known that design of elastic cloaks is much more challenging than that of acoustic cloaks, cloaks of electromagnetic waves or scalar problems of antiplane shear. In this paper, we address fully the fourth-order problem and develop a model of a broadband invisibility cloak for channelling flexural waves in thin plates around finite inclusions. We also discuss an option to employ efficientl...

Analysis for the propagation of plane harmonic thermoelastic waves in an infinite homogeneous orthotropic plate of finite thickness in the generalized theory of thermoelasticity with two thermal relaxation times is studied. The frequency equations corresponding to the extensional (symmetric) and flexural (antisymmetric) thermoelastic modes of vibration are obtained and discussed. Special cases ...

OBJECTIVES This study investigated the effect of extreme cooling methods on the flexural strength, reliability and shear bond strength of veneer porcelain for zirconia. METHODS Vita VM9 porcelain was sintered on zirconia bar specimens and cooled by one of the following methods: inside a switched-off furnace (slow), at room temperature (normal) or immediately by compressed air (fast). Three-po...

This paper is concerned with an investigation into the existence of waves propagating along a free edge of an orthotropic plate, where the edge is inclined at arbitrary angle to a principal direction of the material. After deriving the governing equation and edge conditions, an edge wave ansatz is substituted into this system to reduce it to a set of algebraic equations for the edge wave wave n...

The problem of flexural wave diffraction by a semi-infinite crack in an infinite orthotropic thin plate is considered. Such models have application to the ultrasonic non-destructive inspection of thin components, such as aeroplane wings. For simplicity, the plate is modelled using Kirchhoff theory, and the crack is chosen to be aligned along one of the principal directions of material orthotrop...

In this article, the design of asymmetric bimorph piezoelectric ceramic transducer with loose and fixed edges and with parallel electric excitation is studied. Rectangular piezoelectric ceramic transducers in flexural vibration with straight and parallel nodal lines of vibration are studied. The transducer’s radiation in a plane perpendicular to the surface of the transducer and parallel to the...

Purpose: This study aimed to analyze the fracture resistance of denture base resins relined with either a conventional rigid resin or a new resilient resin. Materials and Methods: Two types of test plates were fabricated by relining the base resin (Acron) with a conventional rigid resin (Tokuso Rebase, TR) or a newly developed relining resin (Tokuyama Rebase II, RII). The specimens were divided...

BACKGROUND Fungal infected denture, which is typically composed of polymethylmethacrylate (PMMA), is a common problem for a denture wearer, especially an elderly patient with limited manual dexterity. Therefore, increasing the antifungal effect of denture by incorporating surface modification nanoparticles into the PMMA, while retaining its mechanical properties, is of interest. AIM OF THE ST...

Current studies indicate that it is possible to obtain soil-cement products with similar performances high performance concrete (HPC). In this context, work aimed evaluate the flexural rupture parameters of high-performance specimens (HPSC) in relation cement percentage. Eighteen HPSC were analyzed, produced compaction moisture 13% and pressure 1.2 MPa. The average flexural-tensile strength was...