Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Saridogan, E(3)
- Sener, S(3)
- Staub, S(3)
- Çuvalci, O.(3)
- Ünker, F.(3)
- Cakir, Tufan(1)
- Kuvat, Ahmet(1)
- Ozturk, Kasif Furkan(1)
- Sadoglu, Erol(1)
- Ünker, Faruk(1)
Yayınlar
- MakaleYalnız künye2023Scopus SJRQ3Gyroscopic suspension for a heavy vehicle
Ünker, Faruk
In this study, an angular momentum generated by a flywheel gyroscope is performed as a suspension to prevent vehicle vibration. The frequency equations are derived and the optimal flywheel speed is obtained for vibration attenuation of the sprung mass. It is observed that the control moment gyroscope (CMG) keeps the sprung mass in the upright position with a small vibration amplitude of a steady motion. The flywheel speed (Ω) is in relation to the amplitude of gimbal motion and the frequency (ω) of the axle’s excitation. Besides, a simulation model of CAE software (RecurDyn) is built to validate the equations of motion.
AtıfScopus6WoS4İncele - MakaleYalnız künye2020Scopus SJRQ3AN OVERVIEW TO THE DYNAMIC BEHAVIOUR OF THE INVERTED T TYPE CANTILEVER RETAINING WALL TAKING INTO ACCOUNT SOIL STRUCTURE INTERACTION PHENOMENON
Cakir, Tufan; Ozturk, Kasif Furkan
The dynamic response of the cantilever retaining walls is affected by many factors such as the geometry of the wall, the earthquake frequency content, the wall flexibility, the backfill characteristics, and the soil structure interaction. Therefore, it may not be possible to analyse all aspects of the dynamic response of the cantilever retaining walls in spite of their simplicity. It is also well known that some unfavourable effects on the behaviour of the walls may impair the balance of the wall. In this context, the study aims to investigate the dynamic response of the T type cantilever retaining wall considering soil structure interaction. In line with this purpose, the soil structure interaction system is produced with a three dimensional finite element model. The seismic analyses are performed in time domain using C-OLC360 component of 1983 Coalinga earthquake, and four different foundation soil systems are used in these analyses. The elasto-plastic behaviour of the backfill and the foundation soil are represented with Drucker-Prager material model. In order to reflect the material damping of the system, Rayleigh damping is utilized considering mass and stiffness proportional dampings. In addition, the viscous boundary dashpot elements which consider the criteria of Lysmer and Kuhlemeyer for wave propagation, are placed around the boundaries of the numerical model. The results are examined in terms of both the stresses and displacements. The findings have revealed that the dynamic response of the T shaped cantilever retaining walls is considerably affected by the soil structure interaction.
AtıfScopus3WoS3İncele - MakaleYalnız künye2020Scopus SJRQ1Dynamic properties of sand-bitumen mixtures as a geotechnical seismic isolation material
Kuvat, Ahmet; Sadoglu, Erol
Geotechnical seismic isolation (GSI) has been emerged as an economical and alternative method in recent years that reduces earthquake that will affect the superstructure. Crumb rubber-granular soil mixtures (SRM) are generally used as damping geomaterial in this method. However, the major disadvantage of SRM is that the addition of rubber leads to significant reduction in stiffness of the granular soil. In this study, dynamic properties (secant shear modulus (Gsec) and damping ratio (D)) of sand and bitumen mixtures (SB) which can be used as damping materials in GSI systems were determined by cyclic triaxial tests. In addition, monotonic triaxial tests were performed to determine the pre- and post-cyclic behavior of the mixtures. In the cyclic tests, the effect of bitumen penetration and content on the energy absorption capacity of the bituminous specimens was examined depending on cyclic stress ratio (CSR), cell pressure and loading frequency. According to the findings, it was determined that higher bitumen penetration and (CSR) result in decrease of Gsec and increase of D, yet the increase in confining pressure and the increase in loading frequency have the opposite effect. For the specimens prepared with both bitumen types, it was specified that the D increased depending on the increase of bitumen content, and the highest Gsec value was observed to be bitumen content of 8%. Moreover, the findings obtained from the monotonic triaxial tests showed that after a high number of cyclic loading, the peak deviatoric stresses of the SB samples increase slightly.
AtıfScopus37WoS32OpenAlex31İncele - BildiriAçık Erişim2015Nonlinear Motion Control of a Column Using a Coupled Gyroscope
Ünker, F.; Çuvalci, O.; Sener, S; Saridogan, E; Staub, S
In this paper, a system of the gyroscopes coupled via the massless torsional springs and the massless torsional dampers mounted on the tip mass of a column subjected to a vibrating base is considered. The coupled gyroscopes are assumed to have reverse angular speeds, and the rotations to eliminate the torques due to the springs and the dampers. Taking advantage of the angular momentum of the rotating gyroscope, gyrostabilizer systems are expected to become more widely actualized as they provide an effective means of motion control with several significant advantages for various structures. The non-linear motions of the gyro-column system and the equations of motion for the system are derived following energy (Lagrange) based approaches and examples provided. On the other hand, the effect of the angular velocities of the gyroscopes are studied, and it is shown that the angular velocity (spin velocity) of a gyroscope has a significant effect on the behavior of the dynamic motion. It is also shown how the dampers and springs due to the motion between the suporting gimbals influence the dynamic behavior of the column. (C) 2015 The Authors. Published by Elsevier Ltd.
AtıfWoS1OpenAlex1İncele - BildiriAçık Erişim2015Seismic Motion Control of a Column Using a Gyroscope
Ünker, F.; Çuvalci, O.; Sener, S; Saridogan, E; Staub, S
Taking advantage of the angular momentum of the rotating gyroscope, gyrostabilizer systems are expected to become more widely actualized as they provide an effective means of motion control with several significant advantages for various structures. In this paper, a symmetric gyro with coupling to the tip mass of a column mounted on a vibrating base is considered. The non-linear motions of the gyro-column system and the equations of motion for the system are derived following energy (Lagrange) based approaches and examples provided. On the other hand, the effect of the angular velocity of the gyroscope is studied, and it is shown that the angular velocity (spin velocity) Omega of gyroscope has a significant effect on the behavior of the dynamic motion. It is also shown how the damper and spring due to the motion between the suporting gimbal and tip mass influence the dynamic behavior of the gyroscope. It was concluded that the numerical investigations of this combined system has not been investigated up to the present time. (C) 2015 The Authors. Published by Elsevier Ltd.
AtıfWoS3OpenAlex9İncele - BildiriAçık Erişim2015Vibration Control of a Column Using a Gyroscope
Ünker, F.; Çuvalci, O.; Sener, S; Saridogan, E; Staub, S
In this paper, the characteristics of a vibration control system utilizing a gyro and its effectiveness in the control of the motion subjected to a seismic ground motion acceleration were studied. Lambda gyro design was presented as a vibration absorber for reduction of the column vibration, which has a potential for application to towers, high-rise buildings and other structures. The non-linear motions of the gyro-column system and the equations of motion for the system are derived following energy (Lagrange) based approaches and examples provided. On the other hand, the effect of the angular velocity of the gyroscope is studied, and it is shown that the angular velocity (spin velocity) Omega of gyroscope has a significant effect on the behavior of the dynamic motion. It is also shown how the damper and spring due to the motion between the suporting gimbal and tip mass influence the dynamic behavior of the gyroscope. (C) 2015 The Authors. Published by Elsevier Ltd.
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