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The paper presents an effective plate formulation based on isogeometric analysis (IGA) and a novel simple quasi-3D hyperbolic shear deformation theory (S-Q3HSDT) to study static bending, free vibration, and buckling behaviors of functionally graded plates. In S-Q3HSDT fashion, five unknowns per node are included; both shear deformation and thickness-stretching effects across the thickness are taken into account; and the awkward shear locking phenomenon is avoided. The requirement for C 1 -continuity in terms of the S-Q3DHSDT is straightforwardly possessed with the aid of inherent high-order continuity of non-uniform rational B-spline (NURBS), which serve as basis functions in our IGA formulation. The superior performance and accuracy of the proposed method is demonstrated through numerous numerical examples. The calculated results are then compared with reference solutions, investigating the effects of boundary conditions, gradient index, and other aspect ratios on mechanical responses of functionally graded plates. [ABSTRACT FROM AUTHOR]

Crumpled paper has recently emerged as a model for disordered media. Here we use wave propagation to probe aluminum foils crumpled into balls made by hand or into cylinders obtained by confinement in a container. Surprisingly, the raw dispersion relations appear to differ from sample to sample. They correspond to bending waves that follow an effective path that is shorter than the distance between the input and output points. This can be interpreted in terms of two modes of propagation: slow bending waves and a fast mode whose possible origin is discussed. In addition, the effective paths behave differently in spheres and in cylinders. These results enable the characterization of the sample structure and point toward the geometric rigidity of the configurations. [ABSTRACT FROM AUTHOR]

Impact of maintenance conditions upon the paper resistance was investigated. Dependencies of tensile strength and resistance to bending of different paper type on paper fibers direction and humidity were presented. [ABSTRACT FROM AUTHOR]

Abstract: This paper addresses the residual denting in the face sheet and corresponding core damage in a locally loaded flat sandwich structure with foam core. The problem is analytically considered in the context of elastic bending of the face sheet accompanied by non-linear deformation of the crushed foam core. The plane and axisymmetric formulations are studied. The obtained solutions allow for the estimation of the magnitude of the residual face dent through the size of the crushed core zone (or vice versa). Thus, the analytical background is proposed for a non-destructive inspection of locally indented/impacted sandwich structures. The solutions are verified experimentally. [Copyright &y& Elsevier]

Based on systematic three-dimensional (3-D), large strain FE limit analyses using elastic- perfectly plastic materials, this paper quantifies the effect of local wall thinning on plastic behavior and TES (twice-elastic-slope) plastic loads for 90° elbows under in-plane bending. The thinning geometry is assumed to be rectangular rather than circular, but the nonlinear geometry effect is fully considered. Results from systematic analyses lead to simple approximations for TES plastic loads, covering a wide range of elbow and thinning geometries. Although the proposed approximations are developed for the case when wall thinning locates in the center of the elbow, it is also shown that they can be equally applied to the case when thinning exists anywhere within the elbow. Brief discussion is made on application of the proposed approximations to estimate maximum load-carrying capacities of elbows with local wall thinning. [ABSTRACT FROM AUTHOR]

In the current paper, the effect of tensile softening parameters, the tensile strength σt and the initial slope k1 of the stress-crack width curve, on the structural size-effect law in bending of concrete are studied by a bending model. The model results show that the size-effect law in bending strength normally presented by flexural strength and beam height diagram (σf-logH) is strongly dependent on σt and k1. With increase of beam height, the general size-effect law in bending can be characterised as a fast reduction stage followed by a stable decreasing stage and finally converged to the tensile strength of concrete. With increasing tensile strength, the σf-logH curve goes up and the value of dσf/dlogH gradually increases. In the meantime, for a given beam height, bending strength increases with increase of k1. The model predictions are compared with experimental results. Good agreement between model predictions and experiments has been obtained. [ABSTRACT FROM AUTHOR]