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Crack formation in cellular solids is often triggered by the presence of flaws caused by the manufacturing process that is used to build them. In thermal management applications, an imperfection embedded in the core of a sandwich panel might have a detrimental thermal impact that is often challenging to predict. This paper focuses on a theoretical study of non-Fourier heat conduction in a sandwich panel with a cracked foam core. With the aim of exploring the thermal response of a panel with porous core and skins made of a single material, we examine the role of crack position, relative density of the foam core, and other geometric parameters of the panel. Based on the assumption that the crack in the core is thermally insulated, i.e. no heat flux can pass through, we obtain the temperature distribution and heat flux intensity factor in the time domain via Fourier and Laplace transforms. The results are visualized in maps that show the influence of the size of the skin relative to that of the foam core and the crack location as well as the antagonist impact that the relative density of the foam core has on the maximum temperature and heat flux. The method presented here can be used to tailor the thermal response of sandwich panels.

The magnetoelastic behavior of heterogeneous thick-walled cylinder with cellular material layers and enduring a dynamic and spatially varying eigenstrain is studied in this paper. The electrically conducting cylinders under plane strain or plane stress condition are subjected to a constant magnetic field. An efficient methodology is developed for the time-harmonic and transient response of multilayered cylinders. The developed methodology is then employed to model the functionally graded cellular cylinders with an arbitrary profile of the relative density distribution via the piecewise homogeneous layer technique. The results are first verified with those available in literature. Then, the effect of relative density, non-homogeneity index, and geometric configuration is examined on the dynamic magnetoelastic response of cylinders containing cellular material layers.

We use the global collocation method, the first and the third-order shear deformation plate theories, the Mori–Tanaka technique to homogenize material properties, and approximate the trial solution with multiquadric radial basis functions to analyze free vibrations of functionally graded plates. Frequencies computed by the present method are found to agree well with those from the analytical solution of Vel and Batra, and the numerical solution of Qian et al. based on the meshless local Petrov–Galerkin formulation. � 2006 Elsevier Ltd. All rights reserved.

The collocation multiquadric radial basis functions are used to analyze static deformations of a simply supported functionally graded plate modeled by a third-order shear deformation theory. The plate material is made of two isotropic constituents with their volume fractions varying only in the thickness direction. The macroscopic response of the plate is taken to be isotropic and the effective properties of the composite are derived either by the rule of mixtures or by the Mori–Tanaka scheme. Effects of aspect ratio of the plate and the volume fractions of the constituents on the centroidal deflection are scrutinized. When Poissons ratios of the two constituents are nearly equal, then the two homogenization techniques give results that are close to each other. However, for widely varying Poissons ratios of the two constituents, the two homogenization schemes give quite different results. The computed results are found to agree well with the solution of the problem by an alternative meshless method. � 2004 Elsevier Ltd. All rights reserved.

Static deformations, and free and forced vibrations of a thick rectangular functionally graded elastic plate are analyzed by using a higher-order shear and normal deformable plate theory (HOSNDPT) and a meshless local Petrov–Galerkin (MLPG) method. All components of the stress tensor are computed from equations of the plate theory. The plate material, made of two isotropic constituents, is assumed to be macroscopically isotropic with material properties varying in the thickness direction only. Effective material moduli are computed by using the Mori–Tanaka homogenization technique. Computed results for static and free vibration problems are found to agree well with their analytical solutions. The response of the plate to impulse loads is also computed for different volume fractions of the two constituents. Contributions of the work include the use of the HOSNDPT and the MLPG method for the analysis of functionally graded plates.

Quasi-continuous wave laser operation of Cr 4+ -doped Y 2 SiO 5 at room temperature was demonstrated for the first time. When pumping with a Nd:YLF laser at 1047 nm, laser operation at 1304 nm with a threshold of 1.5 W was achieved. Room temperature laser operation by pumping with a long pulse flash lamp pumped Nd:YAG laser was also obtained.

International audience; This paper presents an innovative vision for designing equipment suitable for integrated services development by intelligent data acquisition all along the lifecycle. After construction, maintaining the equipment's functions required is one major factor on which depend the performances of the equipment during the remaining of its life. The author so considers the recurring problems that can shrink the expected performances of the equipment may be prevented, using information available firstly for monitoring health conditions of the equipment and secondly for maintenance decision support. The author then proposes to optimize data collection and information of the lifecycle by integrating intelligent data acquisition from the beginning of the equipment design. He also proposes an approach for improving the equipment's maintainability using intelligent systems health condition monitoring for enhancing the concept of service built-in product. Finally, he describes an example, implementing the intelligent data acquisition system for a cumulative diagnostic strategy deployment for equipment health condition monitoring and lifecycle management. The proposed diagnosis strategy, so-called “cumulative diagnosis”, is devised for advanced decision support to predictive maintenance.

This paper presents an innovative vision for designing equipment suitable for integrated services development by intelligent data acquisition all along the lifecycle. After construction, maintaining the equipment's functions required is one major factor on which depend the performances of the equipment during the remaining of its life. The author so considers the recurring problems that can shrink the expected performances of the equipment may be prevented, using information available firstly for monitoring health conditions of the equipment and secondly for maintenance decision support. The author then proposes to optimize data collection and information of the lifecycle by integrating intelligent data acquisition from the beginning of the equipment design. He also proposes an approach for improving the equipment's maintainability using intelligent systems health condition monitoring for enhancing the concept of service built-in product. Finally, he describes an example, implementing the intelligent data acquisition system for a cumulative diagnostic strategy deployment for equipment health condition monitoring and lifecycle management. The proposed diagnosis strategy, so-called “cumulative diagnosis”, is devised for advanced decision support to predictive maintenance.