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A Kahraman - One of the best experts on this subject based on the ideXlab platform.
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an experimental study on the motion transmission error of planetary Gear sets
Volume 10: ASME 2015 Power Transmission and Gearing Conference; 23rd Reliability Stress Analysis and Failure Prevention Conference, 2015Co-Authors: B Boguski, A KahramanAbstract:An experimental study on the overall loaded motion transmission error of planetary Gear sets is presented in this study. A test rig is designed and procured for the purpose of measuring the input-to-output transmission error of planetary Gear sets within a range of input torque. The test matrix includes three distinct phasing conditions (in phase, sequentially phased and counter-phased) of a four-planet Gear set as well as two planet tooth profile modifications. Two different power flow conditions with a fixed planet carrier and a fixed ring Gear are considered. The transmission error results indicate that the phasing condition of the Gear set is the most critical factor resulting in varying levels and numbers of modulation sidebands around the Gear Mesh orders. Planetary Gear sets having in-phase planet Meshes exhibit dominant Gear Mesh harmonic orders with little sideband activity, while sequentially-phased and counter-phased Gear sets show an increase in planetary sideband orders associated with the sun, ring and planet Gears. In addition, the power flow condition with fixed carrier is shown to have higher root-mean-square amplitudes of transmission error than configuration with a fixed ring Gear.Copyright © 2015 by ASME
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Influence of indexing errors on dynamic response of spur Gear pairs
Mechanical Systems and Signal Processing, 2015Co-Authors: Murat Inalpolat, M. Handschuh, A KahramanAbstract:Abstract In this study, a dynamic model of a spur Gear pair is employed to investigate the influence of Gear tooth indexing errors on the dynamic response. This transverse-torsional dynamic model includes periodically-time varying Gear Mesh stiffness and nonlinearities caused by tooth separations in resonance regions. With quasi-static transmission error time traces as the primary excitation, the model predicts frequency-domain dynamic Mesh force and dynamic transmission error spectra. These long-period quasi-static transmission error time traces are measured using unity-ratio spur Gear pairs having certain intentional indexing errors. A special test setup with dedicated instrumentation for the measurement of quasi-static transmission error is employed to perform a number of experiments with Gears having deterministic spacing errors at one or two teeth of the test Gear only and random spacing errors where all of the test Gear teeth have a random distribution of errors as in a typical production Gear.
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a spur Gear Mesh interface damping model based on elastohydrodynamic contact behaviour
International Journal of Powertrains, 2011Co-Authors: A KahramanAbstract:In this study, the damping mechanism at the interface of the mating spur Gear teeth is investigated. The dynamic behaviour of a spur Gear pair is represented by a two Degree-of-Freedom (DOF) nonlinear model with the damping provided by the instantaneous tribological behaviour of the tooth contacts. The shear stress distributions along the tooth surfaces are incorporated with the dynamic model to formulate the periodic Gear Mesh viscous damping. With the assumption the radii of curvature of the contact surfaces can be represented by the ones at the pitch point, a simplified expression for the damping ratio is formulated.
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a methodology to predict surface wear of planetary Gears under dynamic conditions
Mechanics Based Design of Structures and Machines, 2010Co-Authors: A Kahraman, Huali DingAbstract:In this study, a torsional dynamic model and a surface wear model are combined to study the interaction between the surface wear and the dynamic response of planetary Gear sets. The proposed dynamic planetary Gear wear model includes the influence of worn surface profiles on the dynamic tooth forces and the motion transmission error as well as the influence of dynamic tooth forces on wear profiles. The dynamic model includes the Gear backlash and the periodic time variation of Gear Mesh stiffnesses. The model is used to investigate the interactions between the surface wear and the dynamic behavior within both linear and nonlinear response regimes. Several sets of simulation results are used to demonstrate the two-way relationship between nonlinear planetary Gear dynamics and tooth surface wear.
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a dynamic model to predict modulation sidebands of a planetary Gear set having manufacturing errors
Journal of Sound and Vibration, 2010Co-Authors: Murat Inalpolat, A KahramanAbstract:In this study, a nonlinear time-varying dynamic model is proposed to predict modulation sidebands of planetary Gear sets. This discrete dynamic model includes periodically time-varying Gear Mesh stiffnesses and the nonlinearities associated with tooth separations. The model uses forms of Gear Mesh interface excitations that are amplitude and frequency modulated due to a class of Gear manufacturing errors to predict dynamic forces at all sun-planet and ring-planet Gear Meshes. The predicted Gear Mesh force spectra are shown to exhibit well-defined modulation sidebands at frequencies associated with the rotational speeds of Gears relative to the planet carrier. This model is further combined with a previously developed model that accounts for amplitude modulations due to rotation of the carrier to predict acceleration spectra at a fixed position in the planetary transmission housing. Individual contributions of each Gear error in the form of amplitude and frequency modulations are illustrated through an example analysis. Comparisons are made to measured spectra to demonstrate the capability of the model in predicting the sidebands of a planetary Gear set with Gear manufacturing errors and a rotating carrier.
Anand Parey - One of the best experts on this subject based on the ideXlab platform.
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experimental measurement of Mesh stiffness by laser displacement sensor technique
Measurement, 2018Co-Authors: Naresh K Raghuwanshi, Anand PareyAbstract:Abstract Accurate measurement of Mesh stiffness of a given Gear pair is important for understanding the dynamics of Gearboxes. Photoelasticity and strain gauge techniques are the only experimental techniques that are suggested to measure the Mesh stiffness of cracked spur Gear pairs in the literature. In the above two experimental techniques, the Gear body deformation was not taken into account for the Mesh stiffness measurement. In this work, a new experimental technique is designed to measure the Mesh stiffness. For this, a well-established laser displacement sensor technique (LDST) is used. In this method spur Gear tooth deflection is measured along the line of action by using the laser displacement sensor, consequently, Gear Mesh stiffness is calculated. The experiment is also performed on cracked tooth pair to measure the Mesh stiffness. The main advantage of this experimental technique is to measure the total deflection of Gear tooth with Gear body deformation. The investigation shows that the Gear Mesh stiffness is reduced when crack size is increased. For validating the results of the experiment, FEA (finite element analysis) is performed to estimate the Mesh stiffness. The mean Mesh stiffness is measured as 0.76 × 10 4 N/mm by LDST and 0.96 × 10 4 N/mm by FEA for the healthy case. The results of the experiment are found having a good match with that obtained from FE method.
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experimental measurement of spur Gear Mesh stiffness using digital image correlation technique
Measurement, 2017Co-Authors: Naresh K Raghuwanshi, Anand PareyAbstract:Abstract Mesh stiffness is the main cause of Gearbox vibration. A crack in the tooth of Gear reduces the Mesh stiffness. Researchers are trying to evaluate the Mesh stiffness of healthy and faulty Gears by different techniques and modifying the existing techniques for the purpose of vibration based fault detection in Gearboxes. Generally, the Mesh stiffness is evaluated statically for full Mesh cycle and it is used for vibration analysis of the Gearboxes. In this paper, a new experimental technique of Mesh stiffness measurement by using digital image correlation (DIC) technique has been proposed. The experiments were performed on healthy as well as cracked Gears. The obtained results were compared with finite element method (FEM) and analytical method (AM) and showed a good match. The results show that the DIC technique can be used to measure the Mesh stiffness.
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Effect of Mesh stiffness of healthy and cracked Gear tooth on modal and frequency response characteristics of Geared rotor system
Mechanism and Machine Theory, 2017Co-Authors: A. Saxena, Manoj Chouksey, Anand PareyAbstract:Geared rotor systems are used in industrial machinery, automotive applications etc. to provide rotational speed changes and torque variations by transmitting rotational motion from driving shaft to the driven shaft. Gear tooth contact, as modelled using Gear Mesh stiffness and damping, considerably affects the dynamic characteristics of the system. This work primarily studies the effect of Mesh stiffness and damping due to Gear pair on the modal characteristics of the Geared flexible rotor-shaft system supported on compliant bearing. The rotor-shaft is modelled using Timoshenko beam elements; whereas non-proportional viscous damping model is used to represent bearing and Gear Mesh damping. Fatigue loading causes development of Gear tooth crack, which results in reduction of Mesh stiffness. The effect of various cases of cracked Gear tooth has also been investigated on the modal characteristics and frequency response functions of the system. The changes in the modal and frequency response characteristics due to cracked Gear tooth have been compared with that of healthy Geared rotor system. The study may prove helpful in detection of faults developing in the Gear tooth by observing the changes in the dynamic characteristics of the system.
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time varying Mesh stiffness calculation of spur Gear pair considering sliding friction and spalling defects
Engineering Failure Analysis, 2016Co-Authors: A. Saxena, Anand Parey, Manoj ChoukseyAbstract:Abstract Spalling is one of the common tooth surface failures of Gear teeth and is defined as the formation of deeper cavities that are mainly developed from subsurface defects. The time varying Mesh stiffness (TVMS) of Gear pairs, gives significant information about the health of the system. The change indirection of time varying friction on both sides of the pitch line causes the change of Gear Mesh stiffness. This article proposes a computer simulation based approach to study the effect of time varying friction coefficient on the total effective Mesh stiffness for the spur Gear pair. An analytical method to calculate the TVMS of the spur Gear for different spall shapes, size and location considering sliding friction is also proposed in this study. The results show that spall shape, size and location are very important parameters that need to be considered for calculation of TVMS and subsequently to know the dynamic response of the Gear pair in the presence of a spall.
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experimental measurement of Gear Mesh stiffness of cracked spur Gear by strain gauge technique
Measurement, 2016Co-Authors: Naresh K Raghuwanshi, Anand PareyAbstract:Abstract In this paper, an experimental technique based on strain gauge has been proposed to measure the Gear Mesh stiffness of healthy spur Gear as well as of cracked spur Gear pair system. Calculation of Mesh stiffness of healthy and cracked spur Gear tooth are based on strain energy and strain energy release rate respectively. The location of strain gauge plays an important role in calculation of strain energy stored in Gear tooth. The locations of strain gauge on Gear tooth are illustrated for healthy and cracked Gear. Stress intensity factor (SIF) has been calculated by strain gauge technique for calculating the stiffness of cracked pinion tooth. The effect of crack length on Mesh stiffness has been investigated by strain gauge technique and results are compared with the established analytical method.
James J. Zakrajsek - One of the best experts on this subject based on the ideXlab platform.
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analysis of the effects of surface pitting and wear on the vibration of a Gear transmission system
Tribology International, 1996Co-Authors: F K Choy, James J. Zakrajsek, V Polyshchuk, R F Handschuh, D P TownsendAbstract:Abstract A comprehensive procedure to simulate and analyse the vibrations in a Gear transmission system with surface pitting, wear, and partial tooth fracture of the Gear teeth is presented. An analytical model was developed where the effects of surface pitting and wear of the Gear tooth were simulated by phase and magnitude changes in the Gear Mesh stiffness. Changes in the Gear Mesh stiffness were incorporated into each Gear-shaft model during the global dynamic simulation of the system. The overall dynamics of the system were evaluated by solving for the transient dynamics of each shaft system simultaneously with the vibration of the Gearbox structure. In order to reduce the number of degrees-of-freedom in the system, a modal synthesis procedure was used in the global transient dynamic analysis of the overall transmission ststem. An FFT procedure was used to transform the averaged time signal into the frequency domain for signature analysis. In addition, the Wigner-Ville distribution was also introduced to examine the Gear vibration in the joint time-frequency domain for vibration pattern recognition. Experimental results obtained from a Gear fatigue test rig at NASA Lewis Research Center were used to evaluate the analytical model.
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detecting Gear tooth fracture in a high contact ratio face Gear Mesh
STIN, 1995Co-Authors: James J. Zakrajsek, Robert F Handschuh, David G. Lewicki, Harry J. DeckerAbstract:Abstract : This paper summarizes the results of a study in which three different vibration diagnostic methods were used to detect Gear tooth fracture in a high contact ratio face Gear Mesh. The NASA spiral bevel Gear fatigue test rig was used to produce unseeded fault, natural failures of four face Gear specimens. During the fatigue tests, which were run to determine load capacity and primary failure mechanisms for face Gears, vibration signals were monitored and recorded for Gear diagnostic purposes. Gear tooth bending fatigue and surface pitting were the primary failure modes found in the tests. The damage ranged from partial tooth fracture on a single tooth in one test to heavy wear, severe pitting, and complete tooth fracture of several teeth on another test. Three Gear fault detection techniques, FM4, NA4*, and NB4, were applied to the experimental data. (MM)
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detecting Gear tooth fracture in a high contact ratio face Gear Mesh
Meeting of the Society for Machinery Failure Prevention Technology, 1995Co-Authors: James J. Zakrajsek, Robert F Handschuh, David G. Lewicki, Harry J. DeckerAbstract:This paper summarized the results of a study in which three different vibration diagnostic methods were used to detect Gear tooth fracture in a high contact ratio face Gear Mesh. The NASA spiral bevel Gear fatigue test rig was used to produce unseeded fault, natural failures of four face Gear specimens. During the fatigue tests, which were run to determine load capacity and primary failure mechanisms for face Gears, vibration signals were monitored and recorded for Gear diagnostic purposes. Gear tooth bending fatigue and surface pitting were the primary failure modes found in the tests. The damage ranged from partial tooth fracture on a single tooth in one test to heavy wear, severe pitting, and complete tooth fracture of several teeth on another test. Three Gear fault detection techniques, FM4, NA4*, and NB4, were applied to the experimental data. These methods use the signal average in both the time and frequency domain. Method NA4* was able to conclusively detect the Gear tooth fractures in three out of the four fatigue tests, along with Gear tooth surface pitting and heavy wear. For multiple tooth fractures, all of the methods gave a clear indication of the damage. It was also found that due to the high contact ratio of the face Gear Mesh, single tooth fractures did not significantly affect the vibration signal, making this type of failure difficult to detect.
Robert G. Parker - One of the best experts on this subject based on the ideXlab platform.
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vibro acoustic propagation of Gear dynamics in a Gear bearing housing system
Journal of Sound and Vibration, 2014Co-Authors: Tugan Eritenel, Tristan M. Ericson, Robert G. ParkerAbstract:Abstract This work developed a computational process to predict noise radiation from Gearboxes. It developed a system-level vibro-acoustic model of an actual Gearbox, including Gears, bearings, shafts, and housing structure, and compared the results to experiments. The Meshing action of Gear teeth causes vibrations to propagate through shafts and bearings to the housing radiating noise. The vibration excitation from the Gear Mesh and the system response were predicted using finite element and lumped-parameter models. From these results, the radiated noise was calculated using a boundary element model of the housing. Experimental vibration and noise measurements from the Gearbox confirmed the computational predictions. The developed tool was used to investigate the influence of standard rolling element and modified journal bearings on Gearbox radiated noise.
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analytical determination of back side contact Gear Mesh stiffness
Mechanism and Machine Theory, 2014Co-Authors: Yichao Guo, Robert G. ParkerAbstract:Abstract Back-side Gear tooth contact happens when anti-backlash (or scissor) Gears are used, tooth wedging or tight Mesh occurs, or vibration amplitudes are high enough that teeth separate and pass the backlash zone. An accurate description of the back-side Gear tooth Mesh stiffness is needed to study Gear mechanics in such cases. This work studies the time-varying back-side Mesh stiffness and its correlation with backlash by analyzing the relationship between the drive-side and back-side Mesh stiffnesses. Results of this work yield the general form of the back-side Mesh stiffness in terms of the known drive-side Mesh stiffness for an arbitrary Gear pair. The analytical results are confirmed by simulation results from Gear contact analysis software that precisely tracks drive- and back-side Gear tooth contact.
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an investigation of tooth Mesh nonlinearity and partial contact loss in Gear pairs using a lumped parameter model
Mechanism and Machine Theory, 2012Co-Authors: Tugan Eritenel, Robert G. ParkerAbstract:Abstract A three-dimensional lumped-parameter model for a pair of helical Gears is developed and shown to be equivalent to an arbitrary tooth contact force distribution. The nonlinearity of the Gear Mesh is due to portions of Gear teeth contact lines losing contact (partial contact loss). The lumped-parameter model accounts for the net force and moment arising from an arbitrary load distribution including partial contact loss. This model is shown to be equivalent to a four-parameter model defined by a translational stiffness acting at the center of stiffness and a twist stiffness. The twist stiffness generates a moment, which is solely due to the spread of contact across the tooth face. The movement of the translational stiffness across the tooth face generates an additional moment. The four parameters in the model are useful post-processing output quantities to track and interpret the Gear mechanics and the Mesh forces and moments that develop under static or dynamic conditions. The translational and twist stiffnesses and the center of stiffness depend strongly on the relative translation and twist at the Gear Mesh, introducing nonlinearity. Tooth surface modifications smoothen the translational stiffness profile and decrease the twist stiffness. The twist stiffness fluctuates periodically with Gear rotation generating fluctuating moments (shuttling) that can potentially excite vibrations.
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parametric instability of planetary Gears having elastic continuum ring Gears
Journal of Vibration and Acoustics, 2012Co-Authors: Robert G. ParkerAbstract:The parametric instability of planetary Gears having elastic continuum ring Gears is analytically investigated based on a hybrid continuous-discrete model. Mesh stiffness variations of the sun-planet and ring-planet Meshes caused by the changing number of teeth in contact are the source of parametric instability. The natural frequencies of the time invariant system are either distinct or degenerate with multiplicity two, which indicates three types of combination instabilities: distinct-distinct, distinct-degenerate, and degenerate-degenerate instabilities. By using the structured modal properties of planetary Gears and the method of multiple scales, the instability boundaries are obtained as simple expressions in terms of Mesh parameters. Instability existence rules for in-phase and sequentially phased planet Meshes are also discovered. For in-phase planet Meshes, instability existence depends only on the type of Gear Mesh deformation. For sequentially phased planet Meshes, the number of teeth on the sun (or the ring) and the type of Gear Mesh deformation govern the instability existence. The instability boundaries are validated numerically.
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three dimensional nonlinear vibration of Gear pairs
Journal of Sound and Vibration, 2012Co-Authors: Tugan Eritenel, Robert G. ParkerAbstract:Abstract This work investigates the three-dimensional nonlinear vibration of Gear pairs where the nonlinearity is due to portions of Gear teeth contact lines losing contact (partial contact loss). The Gear contact model tracks partial contact loss using a discretized stiffness network. The nonlinear dynamic response is obtained using the discretized stiffness network, but it is interpreted and discussed with reference to a lumped-parameter Gear Mesh model named the equivalent stiffness representation. It consists of a translational stiffness acting at a changing center of stiffness location (two parameters) and a twist stiffness. These four parameters, calculated from the dynamic response, change as the Gears vibrate, and tracking their behavior as a post-processing tool illuminates the nonlinear Gear response. There is a Gear Mesh twist mode where the twist stiffness is active in addition to the well-known Mesh deflection mode where the translational stiffness is active. The twist mode is excited by periodic back and forth axial movement of the center of stiffness in helical Gears. The same effect can occur in wide facewidth spur Gears if tooth lead modifications or other factors such as shaft and bearing deflections disrupt symmetry about the axial centers of the mating teeth. Resonances of both modes are shown to be nonlinear due to partial and total contact loss. Comparing the numerical results with Gear vibration experiments from the literature verifies the model and confirms partial contact loss nonlinearity in experiments.
Harry J. Decker - One of the best experts on this subject based on the ideXlab platform.
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detecting Gear tooth fracture in a high contact ratio face Gear Mesh
STIN, 1995Co-Authors: James J. Zakrajsek, Robert F Handschuh, David G. Lewicki, Harry J. DeckerAbstract:Abstract : This paper summarizes the results of a study in which three different vibration diagnostic methods were used to detect Gear tooth fracture in a high contact ratio face Gear Mesh. The NASA spiral bevel Gear fatigue test rig was used to produce unseeded fault, natural failures of four face Gear specimens. During the fatigue tests, which were run to determine load capacity and primary failure mechanisms for face Gears, vibration signals were monitored and recorded for Gear diagnostic purposes. Gear tooth bending fatigue and surface pitting were the primary failure modes found in the tests. The damage ranged from partial tooth fracture on a single tooth in one test to heavy wear, severe pitting, and complete tooth fracture of several teeth on another test. Three Gear fault detection techniques, FM4, NA4*, and NB4, were applied to the experimental data. (MM)
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detecting Gear tooth fracture in a high contact ratio face Gear Mesh
Meeting of the Society for Machinery Failure Prevention Technology, 1995Co-Authors: James J. Zakrajsek, Robert F Handschuh, David G. Lewicki, Harry J. DeckerAbstract:This paper summarized the results of a study in which three different vibration diagnostic methods were used to detect Gear tooth fracture in a high contact ratio face Gear Mesh. The NASA spiral bevel Gear fatigue test rig was used to produce unseeded fault, natural failures of four face Gear specimens. During the fatigue tests, which were run to determine load capacity and primary failure mechanisms for face Gears, vibration signals were monitored and recorded for Gear diagnostic purposes. Gear tooth bending fatigue and surface pitting were the primary failure modes found in the tests. The damage ranged from partial tooth fracture on a single tooth in one test to heavy wear, severe pitting, and complete tooth fracture of several teeth on another test. Three Gear fault detection techniques, FM4, NA4*, and NB4, were applied to the experimental data. These methods use the signal average in both the time and frequency domain. Method NA4* was able to conclusively detect the Gear tooth fractures in three out of the four fatigue tests, along with Gear tooth surface pitting and heavy wear. For multiple tooth fractures, all of the methods gave a clear indication of the damage. It was also found that due to the high contact ratio of the face Gear Mesh, single tooth fractures did not significantly affect the vibration signal, making this type of failure difficult to detect.
