In order to measure the nonlinear features of micromechanical resonators, a free damped oscillation method based on stair-stepped frequency sinusoidal pulse excitation is investigated. In the vicinity of the resonant frequency, a frequency stepping sinusoidal pulse sequence is employed as the excitation signal. A set of free vibration response signals, containing different degrees of nonlinear ...

Mistuning, imperfections in cyclical symmetry of bladed disks is an inevitable and perilous occurrence due to many factors ncluding manufacturing tolerances and in-service wear and tear. It can cause some unpredictable phenomena such as mode splitting, ode localization and dramatic difference in forced vibration response. In this paper first, a method is presented which calculates he forced vib...

For the purpose of understanding the effects of rotation on wave propagation within a tire’s treadband, the vibration of an inflated, circular cylindrical shell, rotating about a fixed axis has been considered here. The equations of motion of the rotating shell are formulated in a fixed reference frame (i.e., Eulerian coordinates). By assuming wave-like solutions for the free vibration case, th...

Experiments were conducted to determine the effects of frequency and amplitude of vibration on friction. The experimental analysis also seeks to take into account a variety of factors influencing the coefficient of friction such as normal load and surface roughness. An in-house pin-on-disc apparatus was constructed with a spindle speed control and applied forced-feedback to perform the tests. T...

Thin-walled workpieces, such as aero-engine blisks and casings, are usually made of hard-to-cut materials. The wall thickness is very small and it is easy to deflect during milling process under dynamic cutting forces, leading to inaccurate workpiece dimensions and poor surface integrity. To understand the workpiece deflection behavior in a machining process, a new real-time nonintrusive method...

Surface metrology instruments normally require thermal, seismic and acoustic isolation. Shop-floor metrology solutions offer reduced cost and process time. If they operate on the same principles as laboratory devices, an inherent sensitivity to vibration remains. This paper describes a methodology for evaluating ‘environmental tolerance’ and applying it to characterize a recently introduced ‘en...