Contact Stress Evaluation of Involute Gear Pairs, Including the Effects of Friction and Helix Angle

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Santosh S. Patil ◽  
Saravanan Karuppanan ◽  
Ivana Atanasovska
Keyword(s):  
Finite Element ◽  
Friction Factor ◽  
Contact Stress ◽  
Three Dimensional ◽  
Helix Angle ◽  
Spur Gear ◽  
Helical Gear ◽  
Contact Stresses ◽  
Fe Model ◽  
3D Finite Element Method

The aim of this technical brief is to provide a new viewpoint of friction factor for contact stress calculations of gears. The idea of friction factor has been coined, for the calculation of contact stresses along the tooth contact for different helical gear pairs. Friction factors were developed by evaluating contact stresses with and without friction for different gear pairs. In this paper, three-dimensional (3D) finite element method (FEM) and Lagrange multiplier algorithm have been used to evaluate the contact stresses. Initially, a spur gear finite element (FE) model was validated with the theoretical analysis under frictionless condition, which is based on Hertz's contact theory. Then, similar FE models were constructed for 5 deg, 15 deg, 25 deg, and 35 deg helical gear pairs. The contact stresses of these models were evaluated for different coefficients of friction. These results were employed for the development of friction factor.

A Finite-Element-Based Study of the Load Distribution of a Heavily Loaded Spur Gear System With Effects of Transmission Shafts and Gear Blanks

2003 ◽  
Vol 125 (3) ◽  
pp. 625-631 ◽  
Author(s):  
Tian Yong-tao ◽  
Li Cong-xin ◽  
Tong Wei ◽  
Wu Chang-hua
Keyword(s):  
Finite Element ◽  
Load Distribution ◽  
Contact Region ◽  
Three Dimensional ◽  
Gear Wheel ◽  
Spur Gear ◽  
Gear System ◽  
Fe Model ◽  
Tooth Width ◽  
Quadratic Programming Method

Spur gears were typically analyzed in the past using two-dimensional (2-D) Finite Element (FE) models. This is not adequate in many cases. A three-dimensional (3-D) FE model of a spur gear system, which accommodates all the gear teeth, the gear bodies, and the two transmission shafts, is developed in this paper using a sub-structuring method. The load between pinion and gear wheel is delivered by elastic frictional contact. The contact problem is solved according to the FE parametric quadratic programming method. The paper presents the shape of the contact region as well as the load distribution along the tooth width and profile. The results show that the transmission shafts have significant effects on the contact conditions including load distribution, contact region, and load deviation. The proposed method also applies to other types of gearing.

scholarly journals Contact Stress Analysis of Spur Gear Under the Different Rotational Speed by Theoretical and Finite Element Method

2018 ◽  
Vol 7 (4) ◽  
pp. 213 ◽  
Author(s):  
Jwan Kh. Mohammed ◽  
Younis Kh. Khdir ◽  
Safeen Y. Kasab
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Analysis ◽  
Stress Analysis ◽  
Contact Stress ◽  
Rotational Speed ◽  
Three Dimensional ◽  
Spur Gear ◽  
Percentage Error ◽  
Element Method

In this study that spur gears are chosen, contact stress of spur gear is presented under the effect of rotational speed. Three-dimensional simulation of dynamic analysis of gears designed and modeled using ANSYS software. The dynamic analysis included in the determination of dynamic stresses analysis. Contact stress is theoretically calculated and analyzed and numerically estimated using both Hertzian mathematical model and finite element method respectively. Different values of rotational speed used to study its effect on contact stress. Both methods compared by evaluating the percentage error of contact stress, and the modeling of the spur gear and stress analysis of spur gear carried out using SOLID WORK and ANSYS V14, respectively. The most significant note in this study concludes that increasing speed causes vibration and pitting failure due to repetitions.

scholarly journals Contact stress in helical bevel gears

2021 ◽  
Vol 49 (3) ◽  
pp. 519-533
Author(s):  
Edward Osakue ◽  
Lucky Anetor ◽  
Kendall Harris
Keyword(s):  
Contact Stress ◽  
Helix Angle ◽  
Spur Gear ◽  
Helical Gear ◽  
Design Parameters ◽  
Bevel Gears ◽  
Capacity Model ◽  
Previous Solution ◽  
The Common ◽  
Spiral Angle

Helical bevel gears have inclined or twisted teeth on a conical surface and the common types are skew, spiral, zerol, and hypoid bevel gears. However, this study does not include hypoid bevel gears. Due to the geometric complexities of bevel gears, commonly used methods in their design are based on the concept of equivalent or virtual spur gear. The approach in this paper is based on the following assumptions, a) the helix angle of helical bevel gears is equal to mean spiral angle, b) the pitch diameter at the backend is defined as that of a helical gear, and c) the Tredgold's approximation is applied to the helical gear. Upon these premises, the contact stress capacity of helical bevel gears is formulated in explicit design parameters. The new contact stress capacity model is used to estimate the contact stress in three gear systems for three application examples and compared with previous solutions. Differences between the new estimated results and the previous solutions vary from -3% and -11%, with the new estimates being consistently but marginally or slightly lower than the previous solution values. Though the differences appear to be small, they are significant because the durability of gears is strongly influenced by the contact stress. For example, a 5% reduction in contact stress may result in almost 50% increase in durability in some steel materials. The equations developed do not apply to bevel crown gears.

scholarly journals Times Three Dimensional Spur Gear Static Contact Investigations Using Finite Element Method

2016 ◽  
Vol 10 (5) ◽  
pp. 145 ◽  
Author(s):  
Ahmed Mohammed Abdelrhman ◽  
Haidar F. AL-Qrimli ◽  
Husam M. Hadi. ◽  
Roaad K. Mohammed ◽  
Hakim S. Sultan
Keyword(s):  
Finite Element ◽  
Contact Stress ◽  
Gear Tooth ◽  
Three Dimensional ◽  
Element Model ◽  
Spur Gear ◽  
Industrial Applications ◽  
Tooth Surface ◽  
Surface Strength ◽  
Static Contact

<p>A gear is a critical component and can be found in many industrial applications. This investigation develops a three dimensional finite element spur gear model to calculate the contact stress on the gear tooth surfaces. Contact stress is one of the main factors that is used to decide the gears tooth surface strength. In addition there are other important factors such as frictional forces and micro-pits that influence the gear tooth surface. Different analytical techniques have been used to calculate the contact stress of the gear surfaces namely; Hertzian theory and AGMA standards. The analytical results have been compared to the numerical analysis to verify the spur gear finite element model.</p>

scholarly journals Contact Stresses and Dynamic Analysis of involute Spur Gear with FEM Approach

2021 ◽  
Vol 9 (10) ◽  
pp. 1271-1283
Author(s):  
Vidyabhusan Patel
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Contact Stress ◽  
Material Handling ◽  
Fem Analysis ◽  
Spur Gear ◽  
Contact Stresses ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Bending Stresses

Abstract: This paper investigates the characteristics of a gear system including contact stresses, bending stresses, and the transmission errors of gears in mesh. The objective of this paper is to compare values of contact stress and dynamic analysis obtained by theoretical hertz equation with the ANSYS result. A two stage spur gear box has been designed for material handling application by manual calculation and then performs contact stress and dynamic Simulation to ensure its reliable working. The results of the two-dimensional Finite Element Method (FEM) analysis from ANSYS and theoretical results are well comparable. Keywords: involute, spur gear, contact stress, dynamic analysis, finite element analysis

A Possible Strategy for Incorporating Edge Effects in Root Stress Estimation of Helical Gears

1998 ◽  
Author(s):  
Ravikiran Kalluri ◽  
Donald R. Houser
Keyword(s):  
Finite Element ◽  
Edge Effects ◽  
Three Dimensional ◽  
Helix Angle ◽  
Helical Gear ◽  
Element Analysis ◽  
Gear Teeth ◽  
The Difference ◽  
Three Dimensional Finite Element ◽  
Root Stress

Abstract This paper presents the development of a strategy to improve current root stress predictions at the edges of spur and helical gear teeth. Industry demands for higher power density gearboxes require maximum utilization of the load carrying capability of the gear. This requires an accurate understanding of the load distributions and the resulting root stresses. Current analytical methods for predicting root stresses include accurate but time-consuming three-dimensional finite element analysis and some special purpose gear programs. The special analysis programs are computationally faster but rely heavily on empirical mathematical formulations which do not easily lend themselves to the inclusion of edge effects. This effect is seen in the experimental and finite element results due to the difference in stiffness between the edges of helical gear teeth and increases with helix angle. Stress predictions from a state-of-the-art empirical program are compared with experimental and finite element results and a correction suggested for this discrepancy.

The Effect of Varying Degrees of Radial Meniscal Tears on the Knee Contact Stresses: A Finite Element Analysis

2011 ◽  
Vol 304 ◽  
pp. 135-141 ◽  
Author(s):  
Yue Fu Dong ◽  
Ying Hai Dong ◽  
Qing Rong Xu ◽  
Guang Hong Hu ◽  
Wan Peng Dong
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Medial Meniscus ◽  
Meniscal Tear ◽  
Three Dimensional ◽  
Contact Stresses ◽  
Shear Stresses ◽  
Fe Model ◽  
Meniscal Tears ◽  
Element Analysis

Knee osteoarthritis (OA) is believed to result from high levels of the contact stresses on the cartilages and menisci after radial meniscal tears but not clearly proved. This research investigated the effect of varying degrees of radial meniscal tears on the peak compressive and shear stresses in the knee joint. An elaborate three-dimensional (3D) knee finite element (FE) model was developed from CT (computerized tomography) and MRI (magnetic resonance imaging) images. This model was used to model varying degrees of radial meniscal tears (involving 0%-90% radial width of the medial meniscus). Two different conditions were compared: a healthy knee joint and a knee joint with meniscal tears. The peak compressive and shear stresses were found in the posterior region of the medial meniscus and the corresponding zone of the cartilage, and they increased with the increasing width of radial tears. After meniscal tear involving 90% radial width, the peak compressive and shear stresses got their highest values. It shows that meniscal tear greater than 40% radial width drastically increases the contact stresses in the knee joint.

Thermomechanical Coupling of a Hyper-viscoelastic Truck Tire and a Pavement Layer and its Impact on Three-dimensional Contact Stresses

2021 ◽  
pp. 036119812110171
Author(s):  
Angeli Jayme ◽  
Imad L. Al-Qadi
Keyword(s):  
Contact Stress ◽  
Contact Area ◽  
Three Dimensional ◽  
Interaction Model ◽  
Rolling Resistance ◽  
Contact Stresses ◽  
Thermomechanical Coupling ◽  
Temperature Profiles ◽  
Near Surface ◽  
Truck Tire

A thermomechanical coupling between a hyper-viscoelastic tire and a representative pavement layer was conducted to assess the effect of various temperature profiles on the mechanical behavior of a rolling truck tire. The two deformable bodies, namely the tire and pavement layer, were subjected to steady-state-uniform and non-uniform temperature profiles to identify the significance of considering temperature as a variable in contact-stress prediction. A myriad of ambient, internal air, and pavement-surface conditions were simulated, along with combinations of applied tire load, tire-inflation pressure, and traveling speed. Analogous to winter, the low temperature profiles induced a smaller tire-pavement contact area that resulted in stress localization. On the other hand, under high temperature conditions during the summer, higher tire deformation resulted in lower contact-stress magnitudes owing to an increase in the tire-pavement contact area. In both conditions, vertical and longitudinal contact stresses are impacted, while transverse contact stresses are relatively less affected. This behavior, however, may change under a non-free-rolling condition, such as braking, accelerating, and cornering. By incorporating temperature into the tire-pavement interaction model, changes in the magnitude and distribution of the three-dimensional contact stresses were manifested. This would have a direct implication on the rolling resistance and near-surface behavior of flexible pavements.

scholarly journals Biomechanical Effects of Torquing on Upper Central Incisor with Thermoplastic Aligner: A Comparative Three-Dimensional Finite Element Study with and Without Auxillaries

2021 ◽  
pp. 030157422097434
Author(s):  
V Sandhya ◽  
AV Arun ◽  
Vinay P Reddy ◽  
S Mahendra ◽  
BS Chandrashekar ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Central Incisor ◽  
Dimensional Finite Element ◽  
Attachment Model ◽  
Three Dimensional Finite Element ◽  
3D Finite Element Method ◽  
Root Movement ◽  
Maxillary Dentition

Background and Objectives: This study was conducted to determine the effective method to torque the incisor with thermoplastic aligner using a three-dimensional (3D) finite element method. Materials and Methods: Three finite element models of maxilla and maxillary dentition were developed. In the first model, thermoplastic aligner without any auxiliaries was used. In the second and third models, thermoplastic aligner with horizontal ellipsoid composite attachment and power ridge were used, respectively. The software used for the study was ANSYS 14.5 FE. A force of 100 g was applied to torque the upper right central incisor. The resultant force transfer, stress distribution, and tooth displacement were evaluated. Results: The overall tooth displacement and stress distribution appeared high in the model with power ridge, whereas the root movement was more in the horizontal ellipsoid composite attachment model. The model without any auxillaries produced least root movement and stress distribution. Conclusion: Horizontal ellipsoid composite attachment achieved better torque of central incisor than the model with power ridge and model without any auxillaries.

Finite Element Study of the Cutting Mechanics of the Three Dimensional Rock Turning Process

2015 ◽  
Author(s):  
Demeng Che ◽  
Jacob Smith ◽  
Kornel F. Ehmann
Keyword(s):  
Finite Element ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Polycrystalline Diamond ◽  
Close Correlation ◽  
Experimental Results ◽  
Failure Behavior ◽  
Fe Model ◽  
Gas Drilling ◽  
Cutting Mechanics

The unceasing improvements of polycrystalline diamond compact (PDC) cutters have pushed the limits of tool life and cutting efficiency in the oil and gas drilling industry. However, the still limited understanding of the cutting mechanics involved in rock cutting/drilling processes leads to unsatisfactory performance in the drilling of hard/abrasive rock formations. The Finite Element Method (FEM) holds the promise to advance the in-depth understanding of the interactions between rock and cutters. This paper presents a finite element (FE) model of three-dimensional face turning of rock representing one of the most frequent testing methods in the PDC cutter industry. The pressure-dependent Drucker-Prager plastic model with a plastic damage law was utilized to describe the elastic-plastic failure behavior of rock. A newly developed face turning testbed was introduced and utilized to provide experimental results for the calibration and validation of the formulated FE model. Force responses were compared between simulations and experiments. The relationship between process parameters and force responses and the mechanics of the process were discussed and a close correlation between numerical and experimental results was shown.

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