Sharif Digital Repository

Here, the properties of separability of linkages are studied. In general, a linkage is a simple polygonal chain embedded in 3-space with disjoint, straight-line edges, which are fixed-length bars. The internal vertices are called joints. If the two end points are connected then the linkage is a closed linkage, otherwise it is an open linkage. By imposing restrictions on the way the bars in joints can move, three kinds of linkages as rigid, revolute and flexible can be introduced. A motion in a linkage is the motion of its vertices that preserves the length of the bars, and adheres the restrictions on joints. A collection of linkages are said to be separatable if for any distance d, there is... 

Vibration of flexible slender structures under vortex induced vibrations is one of the important subjects in the different fields of engineering such as overhead electricity transmission cables, columns, tall towers and suspended bridges. During passes of flow around bluff bodies, in the certain range of velocity, the Von Karman vortices sheds unsynchronized from two sides of bluff bodies. When structure frequency closed to the vortex shedding frequency, resonant vibrations happen and one can observe vibrations with limited amplitude. Simulations of these phenomenons are so complicated and time consuming prosess, but there is an engineering method for simulating this phenomenon. The aim of... 

In this thesis, the dynamic behavior of a pinned-pinned fractional viscoelastic pipe conveying fluid is examined in the external cross flow. The Galerkin method is employed to discretize the nonlinear coupled equations of motion for viscoelastic pipe conveying fluid in the external cross flow. Consequently, four modes of system are obtained. In addition, direct perturbation method of multiple scale is used to solve the governing nonlinear coupled equations of motion for the fractional viscoelastic pipe conveying pulsating fluid in the external cross flow. Moreover, time response diagrams are drawn in order to investigate under effects of the internal fluid velocity, external fluid reduced...