There are lots of different ways to find the natural frequencies of a rotating system. One of the most effective methods which is used because of its precision and correctness is the application of the transfer matrix. By use of this method the entire continuous system is subdivided and the corresponding differential equation can be stated in matrix form. So to analyze shaft that is this paper ...

Pursuant to the high usage of rotating the disk in aircraft gas turbine engine, turbo pumps in oil and gas industries, steam and gas turbines in power plants, marine gas turbine and other industrial rotary machines designing and getting under the mechanical and thermal loading casued this design and analysis to be as a special significance. These disks are subjected to mechanical and thermal lo...

Title of dissertation: WAVE PROPAGATION IN RODS, SHELLS, AND ROTATING SHAFTS WITH NON-UNIFORM GEOMETRY Mario Toso, Doctor of Philosophy, 2004 Dissertation directed by: Professor Amr Baz Department of Mechanical Engineering The propagation of waves in rods, shells and rotating shafts with variable thickness is studied through numerical models and experimental measurements. All numerical models a...

Vertical axis wind and tidal turbines are a promising technology, well suited to harness kinetic energy from highly turbulent environments such as urban areas or rivers. The power density per occupied land area of two three vertical rotors deployed in close proximity can notably exceed that their horizontal counterparts. Using acoustic Doppler velocimetry, the three-dimensional wake developed d...

Rotating machines are widely used as components of various industries around the world, and its normal operation rotating is important. Thus, condition monitoring fault diagnosis have considerable attention in recent years. Industrial statistics illustrate that 40% total large machine breakdowns happened due to broken bearings, while for small machines, analogous number reaches up 90%. This stu...

In high-speed machining, the maximum stable depth of cut at any spindle rotating frequency depends on the spindle-holder-tool dynamic stiffness as reflected at the tool’s free end. Because this dynamic stiffness can vary with rotating frequency, we have modeled the spindle dynamic response using a finite element-based rotordynamics approach. The spindle shaft is modeled using beam finite elemen...

BACKGROUND AND STUDY AIMS Gastroenterological endoscopists are instructed to bring the target to the 6-o'clock position when they take a biopsy specimen, use a snare, or cut a target organ. This action is performed primarily by rotating the shaft of the endoscopic insertion tube, which can be difficult in some situations when existing endoscopic methods are used. We previously described a metho...

Shaft misalignment is a common problem for many types of rotating systems. It can cause machine breakdowns due to the premature failure of bearings or other components. Common diagnostic approaches rely on detecting increasing vibration response spectra at multiples of the shaft speed. However, in many time-variant systems, such as wind turbines, the speed and load vary considerably, which can ...

in this paper, concept of cross-bispectrum is used to investigate and model vibration interaction due to nonlinearities in faulted drive shafts in an AH-64 helicopter. Most of the currently available vibration-monitoring tools are built around autoand cross-power spectral analyses which have limited value in detecting frequency correlations higher than first order. Studying higher order correla...

Misalignment and unbalance is the most cause of machine vibration. An unbalanced rotor always cause more vibration and generates excessive force in the bearing area and reduces the life of the machine. Understanding and practicing the fundamentals of rotating shaft parameters is the first step in reducing unnecessary vibration, reducing maintenance costs and increasing machine uptime. In this p...