In this article, the axisymmetric mechanical buckling of thin cylindrical shell made of functionally graded material (FGM) is considered. The governing equations for a thin cylinder based on the first-order shell theory and Timoshenko's assumptions are obtained. The equations are derived using the Sanders simplified kinematic relations and the principle of work and energy. The constituent mater...

Thin shallow spherical shell theory is used to derive the general influence function, owing to uniform and/or discrete (actuators) loads, for a thin shallow meniscus-shaped mirror of uniform thickness with a central hole and supported at discrete points. Small elastic deformations are considered. No symmetry on the load distribution constrains the model. Explicit analytical expressions of the s...

In this article, curvature effects on elastic thermal buckling of double-walled carbon nanotubes under axially compressed force are investigated using cylindrical shell model. Also, the small scale effect is taken into account in the formulation. The dependence of the interlayer van der Waals (vdW) pressure on the change of the curvatures of the inner and outer tubes at that point is considered...

A unified boundary element method ~BEM! is developed in this paper to model both the exterior acoustic field and the elastic shell-like structure in a coupled analysis. The conventional boundary integral equation ~BIE! for three-dimensional ~3D! elastodynamics is applied to thin shell-like structures which can have arbitrary shapes and small thicknesses. The nearly singular integrals existing i...

The results of a numerical study of the nonlinear response of thin unstiffened aluminum cylindrical shells with a longitudinal crack are presented. The shells are analyzed with a nonlinear shell analysis code that accurately accounts for global and structural response phenomena. The effects of initial crack length on the prebuckling, buckling and postbuckling responses of a typical shell subjec...

in this study, an intelligent system for sorting closed shell and open shell pistachio nuts, was designed and developed based on combined acoustic and artificial neural network (ann) techniques. the system included a microphone, pc, material handling equipment and an air reject pneumatic mechanism. the microphone, placed under the steel plate, received sound signals generated by the pistachio n...

SM1. Introduction. This supplement contains details that were omitted from the main paper [SM2] because of page limitations. SM2. The Model for the Shell Structure Acoustic Interaction. To avoid switching between the main paper and this supplement, we have included the entire expanded version of Section 2, not only the details and proofs missing from Section 2 of the main paper. SM2.1. Naghdi S...

A two-dimensional, transient, finite-element model has been developed to simulate temperature, shape, and stress development in the steel shell, during the initial stages of solidification in the mold. The model is applied to predict the distorted shape of a vertical section through the shell, during a sudden fluctuation in liquid level at the meniscus. The calculation includes the effects of t...

Indentation experiments on thin films are analyzed by using a rigorous solution to model elastic substrate effects. Two cases are discussed: elastic indentations where film and substrate are anisotropic and elastoplastic indentations where significant material pileup occurs. We demonstrate that the elastic modulus of a thin film can be accurately measured in both cases, even if there is signifi...