Oscillation and dynamic stability of geometrically nonlinear viscous of elastic covers in the elastic medium

3^rd International Conference and Exhibition on Materials Science & Engineering

October 06-08, 2014 Hilton San Antonio Airport, USA

Karimov Abdusamat Ismonovich, Hojimatov Ulugbek Rasuljonovich and Ismanov Muhammadziyo

Accepted Abstracts: Material Sci Eng

Abstract :

Thin-walled constructs are used in civil, aircraft, marine and such as engineering construction. A cylindrical covers are constituent part of thin-walled construct. In many researches were solved problems of bending stress deformed condition of various elements of construct of type of a cylindrical cover. They often are in an interaction with various elastic medium (in a ground, a liquid, gas). In the dynamic interaction between a construct and a medium were established transient processes. These processes can reduce losses of a stability of elements of construct. Values of the critical force received according to the linear theory, have appeared considerably high than real values. In this case construct loses stability. These facts are possible to explain from positions the nonlinear theory of a covers. In the nonlinear theory elastic deformation of a covers will be commensurable with a thickness. In this case in geometrical relation will be additional elements. The movement cylindrical covers are described with nonlinear differential equations. In geometrical nonlinear statement is investigated oscillation and stability of a cylindrical covers. The cylindrical covers are on the static and dynamic loadings. The material cover is orthotropic and possesses rheological properties. Rheological properties of material are described by the hereditary theory of Boltsmana- Voltera. In qualities of criterion of dynamic loss of stability are accepted characteristic values of sags. They equal to the thickness of cover. Nonlinear integro-differential equation is decided with a numerical method. As a result research is defined critical loading on direct axis and exterior pressure (in particular from pressure of elastic medium). There were established associations between the critical loading with parameters orthotropic and factor of elastic medium. There was investigated nonlinear oscillation the cylinder covers on the constant load. There was received numerical value of deformation of construct depending on viscous elastic properties of a material at dynamic application of forces. All results were computed with the program of MAPLE-9.5. Theoretical results can be used in designing various engineering constructions.

Biography :

Karimov Abdusamat Ismonovich has completed his PhD at the Institute of Mechanics of the Academy Sciences of Uzbekistan. He is a scientific researcher and teacher of Mathematics and Mechanics at the Namangan Institute of Engineering and Technology. He has published more than 40 papers in reputed journals of Uzbekistan, Kazakhstan, Latvia and USA. He has 3 patents in Mechanical Engineering for Textile Industry. He participated in 3 research and fundamental studies grants of the Republic of Uzbekistan.