We examine a numerical technique developed to simulate unsteady dispersion and diffusion in coated tubes of arbitrary but axially-constant cross-section. The method is validated against analytical asymptotic solutions produced for tubes of circular section, then applied to the study of dispersion in equivalent tubes of square section, coated on one, two, three or four walls, and in a family of ...

Nowadays, functionally graded materials (FGM) are widely used in many industrial, aerospace and military fields. On the other hand, the interest in the use of shrink-fitted assemblies is increasing for designing composite tubes, high-pressure vessels, rectors and tanks. Although extensive researches exist on thick-walled cylindrical shells, not many researches have been done on shrink-fitted th...

The paper presents a scheme to calculate approximations of reach sets and tubes for linear control systems with time-varying coefficients, bounds on the controls, and constraints on the state. The scheme provides tight external approximations by ellipsoidal-valued tubes. These tubes touch the reach tubes from the outside at each point of their boundary so that the surface of the reach tube is t...

In this paper the energy absorption capacity of stiffened circular composite tube is considered. The governing equations and dynamic equilibrium are first derived and then solved. Additionally, a finite element model of reinforced circular composite tube structure is modeled. At the following, the effects of various parameters such as structural geometry, number of rings and stingers on mechani...

This paper tries to achieve a solution for problems that concern condensation around a flat plate, circular and elliptical tube in by numerical and analytical methods. Also, it calculates entropy production rates. At first, a problem was solved with mesh dynamic and rational assumptions; next it was compared with the numerical solution that the result had acceptable errors. An additional suppor...

This study reports an experimental investigation on the impact behavior of elliptical concrete-filled steel tubular (CFT) columns subjected to lateral loading. A total five CFT columns, including one circular cross-section and four cross-sections, were tested using a horizontal-impact-testing system. The influences velocity, times, geometry dynamic response analyzed. results have shown that spe...