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The validation and updating of dynamic models of golf clubs
Published in Steve Haake, The Engineering of Sport, 2020
M. I. Friswell, M.G. Smart, S. M. Hamblyn, G. Horwood
The golf club is a fascinating structure. The shaft is symmetrical, which would produce repeated natural frequencies if tested in isolation. The addition of the asymmetrical head causes the natural frequencies to separate, and to couple vibration in bending and torsion. By choosing a frame of reference so that one axis is aligned with the principal axis of inertia of the head the bending vibration in one plane is decoupled from the torsion. This decoupling is a vital aid to inferring the measured mode shapes. The usual modal analysis techniques using a roving accelerometer or roving hammer excitation, are impractical on the golf club. Strain gauges may be suitable and this is the subject of further work.
The Measurement of Ultrashort Laser Pulses
Published in Chunlei Guo, Subhash Chandra Singh, Handbook of Laser Technology and Applications, 2021
Rick Trebino, Rana Jafari, Peeter Piksarv, Pamela Bowlan, Heli Valtna-Lukner, Peeter Saari, Zhe Guang, Günter Steinmeyer
On the other hand, Diels and co-workers showed that, once a field has been fit to an interferometric autocorrelation trace, the direction of time could be determined by including a second interferometric autocorrelation measurement—actually a fringe-resolved cross-correlation—in which some glass is placed in one of the interferometer arms. This breaks the symmetry and yields an asymmetrical trace. Then, assuming that the dispersion of the glass is known, Diels and co-workers showed that the two traces could be used to completely determine the pulse field in some cases. Again, however, no study has been published on this algorithm’s performance, and this approach is rarely used.
Adsorption (on Solids) and Absorption (in Fluids) of Gases (CCS Procedures) (Surface Chemistry Aspects)
Published in K. S. Birdi, Surface Chemistry of Carbon Capture, 2019
The molecular arrangement of the solid phase has different characteristics based on the single-crystal structure. For example, a crystalline solid is described through the periodic infinite repetition of an elemental pattern (unit cell) [1]. However, the symmetry of the periodic repetition of the unit cell terminates at the surface, thus creating asymmetrical force interaction. This molecular description has been studied in molecular detail by suitable atomic microscopes.
Effects of tooth root cracks on vibration and dynamic transmission error responses of asymmetric gears: A comparative study
Published in Mechanics Based Design of Structures and Machines, 2023
Onur Can Kalay, Oğuz Doğan, Celalettin Yuce, Fatih Karpat
To summarize, a great deal of research has revealed that asymmetric gears are superior to symmetric designs in terms of bending strength, fatigue propagation life, and impact strength. Plus, it is known that the crack propagation path depends on the backup ratio (Kalay et al. 2021; Kapelevich 2000; Karpat and Ekwaro-Osire 2008; Karpat et al. 2008; Karpat, Ekwaro-Osire, and Khandaker 2008; Karpat, Yuce, and Doğan 2020; Muni and Muthuveerappan 2009; Pedersen 2010; Shuai et al. 2019). However, no research study in the literature has simultaneously evaluated the effect of tooth profile and backup ratio on the gear dynamics characteristics and investigated whether drive side pressure angle (asymmetry) can provide an advantage for early crack diagnosis using vibration and DTE signals. The motivation of the present study is to fill this gap by simultaneously investigating the effects of tooth asymmetry and backup ratio on the vibration and DTE responses in the presence of tooth root cracks and deepen our knowledge regarding the influence of tooth profile on gear dynamics characteristics and early fault diagnosis.