Vibration control of a cylindrical off-shore structure.

Reduction of the Radiating Sound of a Submerged Finite Cylindrical Shell Structure by Active Vibration Control

In this work, active vibration control of an underwater cylindrical shell structure was investigated, to suppress structural vibration and structure-borne noise in water. Finite element modeling of the submerged cylindrical shell structure was developed, and experimentally evaluated. Modal reduction was conducted to obtain the reduced system equation for the active feedback control algorithm. T...

Development of a mechanical earth model in an Iranian off-shore gas field

Wellbore instability is a quite common event during drilling, and causes many problems such as stuck pipe and lost circulation. It is primarily due to the inadequate understanding of the rock properties, pore pressure, and earth stress environment prior to well construction. This study aims to use the existing relevant logs, drilling, and other data from offset wells to construct a precise mech...

Modeling of Vibration of a Fluidized Bed Cylindrical Shell

Passive vibration control: a structure-immittance approach.

Linear passive vibration absorbers, such as tuned mass dampers, often contain springs, dampers and masses, although recently there has been a growing trend to employ or supplement the mass elements with inerters. When considering possible configurations with these elements broadly, two approaches are normally used: one structure-based and one immittance-based. Both approaches have their advanta...

Fractional Optimal Control of a Hollow Cylindrical Structure

This paper presents a general formulation and numerical scheme for Fractional Optimal Control Problem (FOCP) of a distributed system in cylindrical coordinate and uses a hollow cylinder with axial symmetry as the example to demonstrate the method. The fractional derivatives are expressed in the Caputo-Sense. The performance index of FOCP is considered as a function of both the state and the con...