Natural Frequencies and Mode Shapes of Drill Pipe in Subsea Xmas Tree Installation

Resonant Frequencies and Mode Shapes of Switched Reluctance Motors

The wide application of switched reluctance motors (SRM) is limited by their higher vibration and acoustic noise. An accurate determination of resonant frequencies and mode shapes of the SRM stator is therefore essential for low acoustic noise design. Based on the structural finite element method and elasticity theory, 3D vibration modes and resonant frequencies of a 5 hp SRM with 8/6 poles are...

Modal Reduction Based Tracking Control for Installation of Subsea Equipments

This paper proposes a control strategy for the deep sea installation of wellhead equipments hanged by flow line structures, named risers. A fundamental step of this operation is the positioning of the equipment over the wellhead, which can be costly, time-consuming, and unfeasible in bad weather conditions. The approach taken considers the riser structure an Euler-Bernoulli beam submerged in a ...

On the undamped natural frequencies and mode shapes of a finite-element model of the cat eardrum.

This paper presents a three-dimensional finite-element model of the cat eardrum which includes inertial effects. The model is implemented using a hierarchical modeling scheme which permits the mesh resolution to be varied. The static behavior of the model is calculated as a function of mesh resolution in order to check the validity of an earlier model. The first six undamped natural frequencies...

Accurate Experimental Determination of Frequencies, Mode Shapes, and Dynamic Strains in Plate Valves of Reciprocating Compressors

Research on Three-point Centering Device of Cylindrical Drill Pipe

In the process of tightening up and screwing off the iron roughneck, it is required that the center of clamping pliers and the center of drill pipe are coincident, so as to avoid the damage of the circular guide in clamping system, and to ensure the iron roughneck work normally. While the traditional method of centering is artificial in iron roughneck, its precision is low, so it is easy to dam...