Mechanical Resonance Dispersion Revisited
نویسنده
چکیده
Mechanical resonance dispersion is the inelastic response of a solid to a periodic shear stress. Instead of the elastic Young's Modulus, the phenomenon is described by both a real J', and an imaginary J'' component of complex shear compliance, corresponding to in phase and out of phase strain responses, respectively. The experimental results are plots of J' and J'' vs. frequency, which are typically in the audiofrequency range of 10 5600 Hz. Resonances are observed as maxima in J'' and inversions in J' at frequencies corresponding to modes of plastic deformation, which are much lower frequencies (audiofrequency range) than elastic normal modes. The theoretical explanation of Edwin R. Fitzgerald involves particle waves and momentum transfer and leads to a particle-in-a-box frequency formula for these inelastic modes. Unfortunately, most of his and other published raw data were never analyzed by this model. The purpose of this article is to apply this formula to previously uninterpreted resonance dispersion curves and to address some of the earlier criticism of Fitzgerald's work. Results of these calculations support the Fitzgerald Theory to a high degree, demonstrate the importance of impurities and chemical analysis, largely mollify previous criticisms, and suggest the possibility of a new particle wave mass spectroscopy at great distances.
منابع مشابه
Phase analysis and mechanical dispersion perform equally in the detection of myocardial scar on cine magnetic resonance imaging
Introduction Myocardial contraction is a cyclic event. Contraction delay can be described in terms of mechanical dispersion or phase delay of velocity, displacement and local deformation (strain) of segments in apical views of the left ventricle. Our hypothesis was that an increase in the standard deviation of phase would be seen as a consequence of myocardial scar and that this effect could be...
متن کاملIn vivo MR elastography of liver: Comparison to oscillatory rheometer studies of tissue specimen
Introduction: Magnetic Resonance Elastography (MRE) is capable to measure the mechanical properties of living tissue by externally introduced shear vibrations and phase contrast MRI [1]. In multifrequency MRE the complex shear modulus G*(ω) of biological tissue is measured at various mechanical vibration frequencies simultaneously. Viscoelastic tissue parameters can then be calculated by fittin...
متن کاملPosition measurement of a cavity mirror using polarization spectroscopy
A high-reflectivity coated mechanical silicon oscillator with high quality value of the mechanical resonance was employed as a planar rear mirror in a Fabry–Perot interferometer. Active stabilization of the interferometer improves the stability of the resonance and makes it possible to perform sensitive interferometric measurements. The frequency locking of lasers to optical cavities requires t...
متن کاملStrain echocardiography is related to fibrosis and ventricular arrhythmias in hypertrophic cardiomyopathy
AIMS Hypertrophic cardiomyopathy (HCM) patients are at risk of ventricular arrhythmias (VAs). We aimed to explore whether systolic function by strain echocardiography is related to VAs and to the extent of fibrosis by cardiac magnetic resonance imaging (CMR). METHODS AND RESULTS We included 150 HCM patients and 50 healthy individuals. VAs were defined as non-sustained and sustained ventricula...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2014