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The portal axle is a gearbox that is specially designed for off-road driving conditions. It is installed between the wheel and the axle shaft to give higher ground clearance to the vehicle. The modeling and simulation of spur gears in portal axle is important to predict the actual motion behavior. However, gear train design in portal axle is diffic...
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... gear shaft and simulated for three different gear trains. The critical stress results at the gear root fillet and the gear teeth surface of the input and output gear shaft are recorded with gear angular position incremented every 2 interval from 0° to 18°. Finally, discussions and con- clusions are pointed out from the analysis of this work. Fig. 2 shows the assembly model of the three-gear system of the portal axle unit. In this analysis, the model of the input gear shaft, output gear shaft, and idler gear is only considered in FEM analysis to save computing time. This ignores the interaction of the housing fitting and the bearings fitting of the portal ...
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... but they are excited to different kinds of mode shapes such as bending and twisting vibrations. All three gear trains show quite similar natural frequency characteristics as presented from the graph; however, the mode shapes are not the same. The natural frequencies of the gear trains become higher starting at the sixth mode shape and so on. Fig. 12 shows the first eight natural frequencies of the three different gear trains subjected to double pair tooth contact. The first to fifth mode shapes of the three gear trains are of similar natural frequencies but correspond to different mode shapes. This shows that there are possibilities of more than one mode shape occurring for the ...
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... also known as linear contact. Frictional or non- linear contact was ignored in this analysis to reduce comput- ing time. The main scope of this analysis is to obtain bending stress rather than contact stress. Cylindrical support was treated as the ideal bearing support, which only allows rota- tional motion and is applied on the gears as shown in Fig. ...
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... moment of 500 Nm was applied on the shaft of the input gear and the shaft of the output gear was fully constrained to create reaction force between the gear teeth. Fig. 21 shows the maximum bending stress of 291.82 MPa occurring at one side of the root fillet of the input gear. FE simulations predict that the root fillet is more prone to compressive stress rather than tensional ...
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... gear tooth bending stress results calculated from the 3D FE model of the gear train without idler gear were compared to gear tooth bending stress results calculated using the Lewis equation. The gear tooth bending stress was calculated using both methods with respect to the increased torque load. Fig. 22 shows the comparison between the FEM simulation results and theoretical calculation results for gear tooth bending stress. Both methods show a linear relationship in bending stress when plotted against increasing torque load. However, the FEM stress results are slightly higher than the one calculated from the results calculated using ...
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... stress was calculated by using a Hertzian con- tact stress analysis. The Hertzian contact stress of gear teeth is based on the analysis of two cylinders under a radial load. It is assumed in the gear model that the radii of cylinders are the radii of curvature of the involute tooth forms of the mating teeth at the band of contact as shown in Fig. 23.The band of contact between the two cylinders can be calculated as 2a where the deformed distance, a is equal to ( ...
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... W is the normal load, 1 E and 2 E are the modulus of elasticity of the pinion and gear, respectively, 1 v and 2 v are Poisson's ratios of the pinion and gear, respectively, and w b is the face width of pinion. 1 R and 2 R are the respective radii of the involute curve at the contact point, as shown in Fig. ...
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... the ANSYS contact settings, Augmented Lagrange was selected as the solver for the contact non-linearity problem. Since the input gear was being applied load, the input gear contact surface was defined as the 'Contact' and the contact surface of the output gear was the 'Target' of the contact. Fig. 25 shows the side view of the gear tooth contact settings for the gear train with one idler gear. To further enhance the accu- racy of the contact physically and avoid errors, the interface treatment was set to 'Adjust to Touch' and the pinball region was set to 'Auto Detection ...
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... obtain more accurate contact stress results using FEM, a surface mesh refinement of 0.3 mm element size was assigned to the area of teeth surface contact of both the input gear and output gear as shown in Fig. 26. The area of contact at the gear tooth surface representing the finer mesh is approxi- mately 2 mm by 40 mm. The resulting number of nodes is 126463 nodes, and the number of elements formed for the gear train model is 41409 elements. The input gear was hid- den to show the finer mesh elements on the gear tooth contact- ing ...
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... load and constraints were set similar to the one set for FEM bending analysis as shown in Fig. 27. The cylindrical support, which only allows free rotation, represents the virtual bearings to support the gear. Moment of 500 Nm was applied at the shaft of the input gear and the shaft of the output gear is fully constrained. Fig. 28 shows the stress distribution of the two contacting gears in side view when subjected to 500 Nm ...
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... load and constraints were set similar to the one set for FEM bending analysis as shown in Fig. 27. The cylindrical support, which only allows free rotation, represents the virtual bearings to support the gear. Moment of 500 Nm was applied at the shaft of the input gear and the shaft of the output gear is fully constrained. Fig. 28 shows the stress distribution of the two contacting gears in side view when subjected to 500 Nm torque. The maximum stress of 1295.6 MPa occurs at the gear teeth sur- face of the input gear. From the side view, the contact stress distribution between the two gears is not precise because the contacting nodes are not arranged in a ...
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... more detailed contact stress distribution on the gear tooth surface of the input gear can be seen in Fig. 29 after putting input gear model to hidden. It is expected that a long stretch of high stress band contact should be formed along the gear tooth surface. However, this is not the case due to uneven node for- mation along the gear tooth ...
Citations
... Grujicic et al. [14] employed a tooth-stress analysis to investigate the influence of transmitted torque and gear misalignment on the maximum equivalent and principal stress for fatigue-crack initiation in the intermediate stage of the wind turbine gearbox. The maximum contact and bending stress of gear teeth were determined using FEM for three separate gear trains with varied angular positions considering single and double pair tooth contact [15]. The FEM stress findings were verified by the results generated from two analytical theories that showed high agreement with an average deviation of 5%. ...
Wind turbine gearbox is the most critical subsystem
which determines the reliability of the wind turbine. This is due to
their high failure rates and long downtime per failure. Therefore,
successful analysis of the maximum stress criterion provides a
better understanding of failure occurrences. Investigating the
maximum stresses in meshing gears typically reveals the
occurrence of failure. These assist designers, engineers, and
maintenance personnel in making strategic decisions to improve
reliability and optimize operation. Because of its high
susceptibility to cracks and pits, the sun gear of the wind turbine
gearbox is the focus of this study. Furthermore, previous research
has primarily focused on singular fault with no known study on
the occurrence of two simultaneous defects in the same tooth
under dynamic conditions. This investigation helps to distinguish
the effects of singular and simultaneous fault occurrences on this
failure parameter. The overall maximum stress of the healthy
model is 1781.5MPa, while the overall max stresses of the cracked,
pitted, and simultaneous fault models are 1841MPa, 2957.5MPa,
and 2961.9MPa respectively. Furthermore, the percentage mean
deviations of the full faulty responses from the healthy response
were computed as 25.91%, 59.08%, and 58.92%, respectively. It is
established that tooth pits are more efficiently diagnosed using the stress criterion than tooth cracks. Finally, in the event of a
simultaneous occurrence, examining the max stress captures the
most dominant fault.
... Lundvall [51] established a multibody model by superposing small displacement elasticity obtained using the FE method on the rigid body motions equation and analyzed the influence of friction on the dynamic transfer error. Ooi [52] established an FE model of a portal axle gear system, calculated the modal parameters of the system, and analyzed the stress distribution with different angular positions. Wu [53] calculated the dynamic TVMS and dynamic transmission error (DTE) of a helical gear pair utilizing the three-dimensional contact FE method. ...
This paper presents an efficient method for obtaining the dynamic mesh stiffness and dynamic response of a helical gear pair. Unlike the traditional dynamic model that utilizes a time-dependent sequence, the mesh stiffness using the presented method is updated according to the gear displacement vector at each sub-step of the numerical calculation. Three-dimensional loaded tooth contact analysis (3D LTCA) is used to determine the mesh stiffness, and a surrogate model based on sparse polynomial chaos expansion (SPCE) is proposed to improve the computational efficiency, which is achieved by reducing the number of coefficients in the polynomial chaos expansion (PCE) model though a quantum genetic algorithm. During the calculation, the gear displacement vector at each sub-step is converted into the changes in center distance, misalignment angle, and mesh force, which are then introduced into the SPCE model to update the mesh stiffness for subsequent calculations. The results suggest that the SPCE model exhibits high accuracy and can significantly improve the computational efficiency of the PCE model, making it suitable for dynamic calculations. Upon updating the mesh stiffness during the dynamic calculation, the mesh stiffness declines, the dynamic transmission error (DTE) increases, and the frequency components of the responses change significantly.
... whose shaw's hardness is 80o has better modal characteristics than traditional cycloidal drives by more effectively avoiding resonance region. JongBoonOoi [7] used modal analysis on three different gear trains of the portal axle unit was studied using FEM simulation under free-stress state and pre-stressed state. ...
This paper presents the effect of composite materials that included limited damping material on vibrating structures modal. The current study selected two symmetrical laminates having [(0/90) 66 ] S carbon-epoxyE502, and glass-epoxyCG202. Measurements are carried out on structure of the spur gears by using hammer test. Comparisons of the results of the experimental and finite-element study found that the damping ratio and the natural frequencies of structures are well thoroughly investigated. Also experimentally determined were natural frequency, frequency response, and damping ratio of the structures. The gear was modelled in CAD SOLIDWORKS software in this paper while in ANSYS ACP Workbench 17.2 modal and response harmonic analysis were performed for various boundary conditions. It can be concluded that the composite materials are actually perfect for the noise and vibration reduction. The results show that the composite material can have a spectacular effect on the weight of the drive system without considering strength. 1.INTRODUCTION Gears are the most important components in modern mechanical engineering world. The use of gearshas more common in all the industries. The advantages of spur gear are simplicity in design and can bemanufactured easily, economically and less maintenance. At present scenario composite gears plays an important role in wide space of research especially in gear motors, gear pumps, electromechanical actuators and drive shafts for car etc., Composite gears have better mechanical characteristics like wear resistance, corrosion resistance, lubricant free, noiseless, high strength to weight ratio[1].Metal matrix composites (MMCs) are an essential product used in engineering materials. This product has wide applications in automotive, aerospace, and other uses[2].Robert F. Handschuh [3] investigated hybrid gear (composite material-metallic) at NASA Glenn Research Center. Although the design was not optimized for weight, the composite gears were found to be 20 percent lighter that the all-steel gears. Fee vibration modes and vibration/noise test were also conduct to compare the vibration and damping characteristic of the Hybrid Gear to all-steel gears. The initial results indicate that this type of hybrid design may have a dramatic effect on drive system weight sacrificing strength.Omer Yavus Bozkurt [4] was measured dynamic characteristic of Basalt Epoxy composite laminates by using an experimental setup according to ASTM E756, fibre orientation of basalt/epoxy, and the laminates having higher fibre 5orientation angle had higher damping ratios , also the increase in angle of fibre orientation from 0 o to 45 o resulted in decrease in natural frequency. Bagul
... Hanjun Jiang [4] presented an analytical study on the contact stiffness of helical teeth with and without crack. JongBoon Ooi [5] carried out a modal analysis on a gear train with and without an idler gear, he took into account the type of contact either double or pair. the results obtained by the FEM method were compared by the analytical equations of AGMASantosh S. Patil [6] carried out a study on the contact pressure of helical gears by the 3D finite element method, taking into account the variation of friction in the contact zone. ...
Noise and vibrations are the main reasons for failure of transmission system, minimizing the noise and vibration in power system is a constant development, gear faults are the main sources that create vibrations in mechanical systems. According to our experience, to apply at the cement plant of Hamma Bouziane in Industrial Zone of Constantine and using very sophisticated measuring means (OMNITREND processing software) and the development of the vibration sensors, an anomaly was detected in the part (pinion / crown). The objective of this research is to determine the influence of the defect size on the mechanical behavior of helical gear under dynamic load and the different mode shape of vibration of pinion-crown. The distribution of contact stresses, bending stresses was investigated using FEM and the obtained stresses are then compared with AGMA standard. The modeling of gears was performed using SOLID WORKS software and imported into the finite element code ANSYS.
... whose shaw's hardness is 80o has better modal characteristics than traditional cycloidal drives by more effectively avoiding resonance region. JongBoonOoi [7] used modal analysis on three different gear trains of the portal axle unit was studied using FEM simulation under free-stress state and pre-stressed state. ...
This paper presents the effect of composite materials that included limited damping material on vibrating structures modal. The current study selected two symmetrical laminates having [(0/90)66]S carbon-epoxyE502, and glass-epoxyCG202. Measurements are carried out on structure of the spur gears by using hammer test. Comparisons of the results of the experimental and finite-element study found that the damping ratio and the natural frequencies of structures are well thoroughly investigated. Also experimentally determined were natural frequency, frequency response, and damping ratio of the structures. The gear was modelled in CAD SOLIDWORKS software in this paper while in ANSYS ACP Workbench 17.2 modal and response harmonic analysis were performed for various boundary conditions. It can be concluded that the composite materials are actually perfect for the noise and vibration reduction. The results show that the composite material can have a spectacular effect on the weight of the drive system without considering strength. 1.INTRODUCTION Gears are the most important components in modern mechanical engineering world. The use of gears has more common in all the industries. The advantages of spur gear are simplicity in design and can be manufactured easily, economically and less maintenance. At present scenario composite gears plays an important role in wide space of research especially in gear motors, gear pumps, electromechanical actuators and drive shafts for car etc., Composite gears have better mechanical characteristics like wear resistance, corrosion resistance, lubricant free, noiseless, high strength to weight ratio[1].Metal matrix composites (MMCs) are an essential product used in engineering materials. This product has wide applications in automotive, aerospace, and other uses[2].Robert F. Handschuh [3] investigated hybrid gear (composite material-metallic) at NASA Glenn Research Center. Although the design was not optimized for weight, the composite gears were found to be 20 percent lighter that the all-steel gears. Fee vibration modes and vibration/noise test were also conduct to compare the vibration and damping characteristic of the Hybrid Gear to all-steel gears. The initial results indicate that this type of hybrid design may have a dramatic effect on drive system weight sacrificing strength.Omer Yavus Bozkurt [4] was measured dynamic characteristic of Basalt Epoxy composite laminates by using an experimental setup according to ASTM E756, fibre orientation of basalt/epoxy, and the laminates having higher fibre 5orientation angle had higher damping ratios , also the increase in angle of fibre orientation from 0 o to 45 o resulted in decrease in natural frequency. Bagul
... Gear vibrations and stresses are main worries in most planetary gear transmission mechanisms, where the obvious problem may be noise or dynamic forces [2]. Thus, a single failure or damage to one of these components disrupts the functioning of the whole system [3]. Planetary gears are fundamental parts of many accuracy power transmission elements. ...
... The planetary gear train is the most critical component in the power gear transmission systems, so a single failure or damage to one of these components disrupts the functioning of the whole system [7]. ...
... To be able to drive off the pavement, off-road vehicles need several characteristics. [3] The portal axle designed to give desired ground clearance to the vehicle system. In the project the design of this portal axle is to be carried out for different gear train as spur & helical and hence to do comparative study for both the gear trains [4] . ...
... Construction of gears is a combination of science and design. There are various methods for constructing the gear [20][21][22]. Lewis -formula and Hertz -equation are applied because of various influencing factors. In this study was carried out test on contact gear stress, to determine relation of stress – deformation characteristics [18, 23]. ...
Spur gears are the simplest type of gears, which are widely used in modern structures. One of the main tasks of researchers in application areas of gears within the responsible structures, especially in spacecraft propulsion mechanisms, is to obtain compact gear, small size and weight, while maintaining or improving functional characteristics. Therefore there was a need to explore new materials that could be used as a replacement for steel in the manufacturing of gears. A good alternative for steel is hybrid composite with aluminum matrix and various reinforcements, which provides adequate mechanical properties, while reducing the weight of the gear. The paper presents the modeling of gears and analysis of their stress-deformation state using the finite element method. Steel and composite gears made from aluminum matrix with various reinforcements were tested. Results from this study show that the gear made of composite material offers enhanced features compared to metal gears.
... The modal behaviors of a low-speed shaft were investigated in Refs. [11,12], in which the bearings are considered as rigid and elastic restrains, respectively. The modal frequencies of rigid restrain are smaller than those of elastic restrain. ...
Wind turbine gearbox (WTG), which functions as an accelerator, ensures the performance and service life of wind turbine systems. This paper examines the distinctive modal properties of WTGs through finite element (FE) and experimental modal analyses. The study is performed in two parts. First, a whole system model is developed to investigate the first 10 modal frequencies and mode shapes of WTG using flexible multibody modeling techniques. Given the complex structure and operating conditions of WTG, this study applies spring elements to the model and quantifies how the bearings and gear pair interactions affect the dynamic characteristics of WTGs. Second, the FE modal results are validated through experimental modal analyses of a 1.5 WM WTG using the frequency response function method of single point excitation and multi-point response. The natural frequencies from the FE and experimental modal analyses show favorable agreement and reveal that the characteristic frequency of the studied gearbox avoids its eigenfrequency very well.
