In this paper, a numerical solution has been developed for hollow circular cylinders made up of orthotropic material which is subjected to twist using micro polar theory. The effect of twisting moment and material internal length on hollow thick-walled circular cylinder made up of micro polar orthotropic material is investigated. Finite difference method has been used to exhibit the influence o...

The aim of this paper is to determine the stress levels at the end of a long slender shaft such as a drilling assembly used in the oil or gas industry using a mathematical model in real-time. The torsional deflection experienced by this type of drilling shaft (about 4 KM length and 20 cm diameter hollow shaft with a thickness of 1 cm) can only be determined using a distributed modeling techniqu...

In this study, two-dimensional electro-mechanical analysis of a composite rotating shaft subjected to non-axisymmetric internal pressure and applied voltage is investigated where hollow piezoelectric shaft reinforced by boron nitride nanotubes (BNNTs). Composite structure is modeled based on piezoelectric fiber reinforced composite (PFRC) theory and a representative volume element has been cons...

Abstract. In this paper we derive bounds on the torsional rigidity for coated fiber reinforced shafts. The bounds are used to assess the optimality or suboptimality of fiber reinforcement configurations. This investigation focuses on coated fiber reinforcements with circular cross section. It is shown how the effective antiplane shear modulus and torsional rigidity of each coated fiber are used...

Dynamic behavior of a circular shaft with geometrical nonlinearity and constant spin, subjected to periodic axial load is investigated. The case of parametric combination resonance is studied. Extension of shaft center line is the source of nonlinearity. The shaft has gyroscopic effect and rotary inertia but shear deformation is neglected. The equations of motion are derived by extended Hamilto...

A 50-year-old man with paroxysmal atrial fibrillation underwent pulmonary vein isolation (PVI) using a cryoballoon. During the PVI procedure, a circular diagnostic catheter (CDC) was wedged deeply into the right PV (RPV). The lung tissues seemed to be tightening around the CDC. After various attempts to resolve the situation, the shaft of the CDC was completely torn, and the circular part remai...

In this study, two-dimensional electro-mechanical analysis of a composite rotating shaft subjected to non-axisymmetric internal pressure and applied voltage is investigated where hollow piezoelectric shaft reinforced by boron nitride nanotubes (BNNTs). Composite structure is modeled based on piezoelectric fiber reinforced composite (PFRC) theory and a representative volume element has been cons...