Mesh stiffness of micro-spur gears by finite element formulations based on modified couple stress theory

Pehlivanoglu, Yucel
Aydogan, M. Ozgur
Finite element formulations developed for micro-sized structures are utilized for the determination of mesh stiffness of micro-spur gear pairs. The equations are based on Modified Couple Stress Theory developed for micro-beams. Timoshenko and Euler-Bernoulli type formulations are used separately to observe the difference. Calculations are performed for micro-gear pairs having two different module types and the stiffness of both double and single mesh regions are obtained. The results reveal the size effect on the mesh stiffness of micro-gears, and can be used in the future for more advanced gear configurations. The comparison study shows that performing calculations with classical continuum theories as well as Euler-Bernoulli type beam formulations can cause significant errors in the mesh stiffness depending on the size of micro-gears.


Design optimization of a laser path length controller through numerical analysis and experimental validation
Fenercioglu, Tevfik Ozan; Yalçınkaya, Tuncay (IOS Press, 2019-01-01)
As an integral part of Strapdown Inertial Navigation Systems, ring laser gyroscopes (RLG) are exposed to joint loading conditions where thermal, static and dynamic loads occur simultaneously. The effects of different loading conditions on overall RLG performance should be addressed in parallel for an optimum design. A crucial aspect in this process is the development of the path length controller (PLC), consisting of a mirror, a composite piezo electric bending actuator and other motion transfer elements. T...
Phonon dispersions and elastic constants of disordered Pd-Ni alloys
Kart, SO; Tomak, Mehmet; Cagin, T (Elsevier BV, 2005-01-31)
Phonon frequencies of Pd-Ni alloys are calculated by molecular dynamics (MD) simulation. Lattice dynamical properties computed from Sutton-Chen (SC) and quantum Sutton-Chen (Q-SC) potentials as a function of temperature are compared with each other. We present all interatomic force constants up to the 8th nearest-neighbor shell obtained by using the calculated potential. Elastic constants evaluated by two methods are consistent with each other. The transferability of the potential is also tested. The result...
Trap characterization by photo-transferred thermoluminescence in MgO nanoparticles
IŞIK, MEHMET; Hasanlı, Nızamı (Elsevier BV, 2018-05-15)
Shallow trapping centers in MgO nanoparticles were characterized using photo-transferred thermoluminescence (TL) measurements. Experiments were carried out in low temperature range of 10-280 K with constant heating rate. Shallow traps were filled with charge carriers firstly by irradiating the sample at room temperature using S-90/Y-90 source and then illuminating at 10 K using blue LED. TL glow curve exhibited one peak around 150 K. Curve fitting analyses showed that this peak is composed of two individual...
Direct measurement of molecular stiffness and damping in confined water layers
We present direct and linear measurements of the normal stiffness and damping of a confined, few molecule thick water layer. The measurements were obtained by use of a small amplitude (0.36 Angstrom), off-resonance atomic force microscopy technique. We measured stiffness and damping oscillations revealing up to seven molecular layers separated by 2.526+/-0.482 Angstrom. Relaxation times could also be calculated and were found to indicate a significant slow-down of the dynamics of the system as the confining...
Forward and reverse bias current-voltage characteristics of Au/n-Si Schottky barrier diodes with and without SnO2 insulator layer
GÖKÇEN, MUHARREM; ALTINDAL, ŞEMSETTİN; Karaman, M.; Aydemir, U. (Elsevier BV, 2011-11-01)
The effects of interfacial insulator layer, interface states (N-ss) and series resistance (R-s) on the electrical characteristics of Au/n-Si structures have been investigated using forward and reverse bias current-voltage (I-V) characteristics at room temperature. Therefore, Au/n-Si Schottky barrier diodes (SBDs) were fabricated as SBDs with and without insulator SnO2 layer to explain the effect of insulator layer on main electrical parameters. The values of ideality factor (n), R-s and barrier height (Phi(...
Citation Formats
Y. Pehlivanoglu, M. O. Aydogan, and B. SABUNCUOĞLU, “Mesh stiffness of micro-spur gears by finite element formulations based on modified couple stress theory,” MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, pp. 0–0, 2020, Accessed: 00, 2020. [Online]. Available: