An XFEM-Based Approach to Fatigue Crack Growth in Press-Fit Spur Gears

2022 ◽  
pp. 095440892110727
Author(s):  
Fatih Güven
Keyword(s):  
Internal Pressure ◽  
Crack Growth ◽  
Tangential Stress ◽  
Power Transmission ◽  
Gear Tooth ◽  
Tangential Direction ◽  
Spur Gears ◽  
Extended Finite Element ◽  
Interference Fit ◽  
Press Fit

Gears mounted on a shaft via interference fit are the subject of an internal pressure which is essential for power transmission between gear and shaft. The pressure between shaft and gear is responsible for additional stresses occurring both in shaft and gear. This study examines the effect of stresses arising due to the interference on the crack growth that exists at the root of the gear tooth. The numerical analyses were conducted on models having different rim thicknesses by using the extended finite element method that allows mesh-independent crack modeling and does not need re-meshing. The results showed that internal pressure yields additional stresses in the tangential direction. The increment in tangential stress changed the location and intensity of the maximal 1st principal stress and accelerated crack growth. As the tightness of the fit increased, the crack turned towards the rim rather than towards the tooth. As the crack growth through the rim may cause a catastrophic failure of gear, the increment in tangential stress due to internal pressure is crucial for the fatigue life of the gear.

Effect of design parameters on stresses occurring at the tooth root in a spur gear pressed on a shaft

2021 ◽  
pp. 095440892199529
Author(s):  
Fatih Güven
Keyword(s):  
Internal Pressure ◽  
Tangential Stress ◽  
Spur Gear ◽  
Design Parameters ◽  
Interference Fit ◽  
Gear Design ◽  
Compact Design ◽  
Fit Tolerance ◽  
Moderate Stress ◽  
Good Agreement

Gears are commonly used in transmission systems to adjust velocity and torque. An integral gear or an interference fit could be used in a gearbox. Integral gears are mostly preferred as driving gear for a compact design to reduce the weight of the system. Interference fit makes the replacement of damaged gear possible and re-use of the shaft compared to the integral shaft. However, internal pressure occurs between mating surfaces of the components mated. This internal pressure affects the stress distribution at the root and bottom land of the gear. In this case, gear parameters should be re-considered to assure gear life while reducing the size of the gear. In this study, interference fitted gear-shaft assembly was examined numerically. The effects of rim thickness, profile shifting, module and fit tolerance on bending stress occurring at the root of the gear were investigated to optimize gear design parameters. Finite element models were in good agreement with analytical solutions. Results showed that the rim thickness of the gear is the main parameter in terms of tangential stress occurring at the bottom land of the gear. Positive profile shifting reduces the tangential stress while the pitch diameter of the gear remains constant. Also, lower tolerance class could be selected to moderate stress for small rim thickness.

Investigation on Structural Steel and Silicon Carbide Aluminum Metal Matrix Composite Spur Gears Using PTC Creo and ANSYS 16.0

2018 ◽  
Vol 937 ◽  
pp. 33-41
Author(s):  
S. Nallusamy ◽  
M. Rajaram Narayanan ◽  
S. Saravanan
Keyword(s):  
Composite Materials ◽  
Structural Steel ◽  
Power Transmission ◽  
Gear Tooth ◽  
Minimum Weight ◽  
Spur Gear ◽  
Spur Gears ◽  
Assembly Model ◽  
Aluminum Metal Matrix Composite ◽  
Engineering And Technology

In the field of Engineering and Technology, Gear is one of the most significant and essential component in mechanical power transmission system. General devices have major applications in various fields like automotives, industrial rotational machines, lifting devices, etc. Gears are usually subjected to fluctuating loads while in action. Gear tooth mainly fails due to excessive bending stress and excessive contact stress. Thus while designing the gear it is very necessary and vital to analyze the stresses induced in the gear for its safe operation. Weight reduction of gear is also one of the main design criteria as it has a great role in improving the efficiency of the entire system. Nowadays engineering components made up of composite materials and plastics find increasing applications. The components made by the composite materials provide reasonable mechanical properties with minimum weight. The objective of this research is to develop the spur gear and pinion assembly model using engineering simulation PTC Creo and imported to 3-D design software ANSYS workbench 16.0 for working on the static structural analysis. The analysis was carried out by considering different materials for gears like structural steel, polycarbonate and 20%AlSiC. From the observed results it was found that, 20%AlSiC composite material has mass reduction of about 45%, hence it is suitable for light weight applications.

A Virtual Tool for Wear Simulation of Standard and Non-Standard Spur Gears

2012 ◽  
Author(s):  
F. Karpat ◽  
S. Ekwaro-Osire ◽  
E. Karpat
Keyword(s):  
High Speed ◽  
High Performance ◽  
Failure Modes ◽  
Power Transmission ◽  
Wear Behavior ◽  
Gear Tooth ◽  
Load Capacity ◽  
High Load ◽  
Wear Depth ◽  
Spur Gears

There is an industrial demand for the increased performance of mechanical power transmission devices. This need in high performance is driven by high load capacity, high endurance, low cost, long life, and high speed. New designs and modifications in gears have been investigated to obtain high load carrying capacity and increased life with less volume and weight. Tooth wear is one of the major failure modes in gears. Although there are different classifications of wear mechanisms, wear on gears can be simply classified as mild wear, pitting, and severe wear, depending on the wear rate. These types of wear may lead to power transmission losses, decreased efficiency, increased vibration and noise, and gear tooth failure. This paper deals with the simulation of wear for standard and non-standard gears using an analytical approach. A numerical model for wear prediction of gear pair is developed. A wear model based on Archard’s equation is employed to predict wear depth. A MATLAB-based virtual tool is developed to analyze wear behavior of standard and non-standard spur gears with various gear parameters. In this paper, this virtual tool is introduced by using many numerical examples.

scholarly journals Fatigue Crack Growth Analysis with Extended Finite Element for 3D Linear Elastic Material

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 397
Author(s):  
Yahya Ali Fageehi
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Crack Propagation ◽  
Crack Growth ◽  
Mixed Mode ◽  
Propagation Path ◽  
Loading Conditions ◽  
Extended Finite Element ◽  
Linear Elastic

This paper presents computational modeling of a crack growth path under mixed-mode loadings in linear elastic materials and investigates the influence of a hole on both fatigue crack propagation and fatigue life when subjected to constant amplitude loading conditions. Though the crack propagation is inevitable, the simulation specified the crack propagation path such that the critical structure domain was not exceeded. ANSYS Mechanical APDL 19.2 was introduced with the aid of a new feature in ANSYS: Smart Crack growth technology. It predicts the propagation direction and subsequent fatigue life for structural components using the extended finite element method (XFEM). The Paris law model was used to evaluate the mixed-mode fatigue life for both a modified four-point bending beam and a cracked plate with three holes under the linear elastic fracture mechanics (LEFM) assumption. Precise estimates of the stress intensity factors (SIFs), the trajectory of crack growth, and the fatigue life by an incremental crack propagation analysis were recorded. The findings of this analysis are confirmed in published works in terms of crack propagation trajectories under mixed-mode loading conditions.

scholarly journals An Extended Finite Element Method (XFEM) Study on the Elastic T-Stress Evaluations for a Notch in a Pipe Steel Exposed to Internal Pressure

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 507
Author(s):  
K. Yakoubi ◽  
S. Montassir ◽  
Hassane Moustabchir ◽  
A. Elkhalfi ◽  
Catalin Iulian Pruncu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Extended Finite Element Method ◽  
Research Study ◽  
Extended Finite Element ◽  
T Stress ◽  
Cracked Structures ◽  
Element Method

The work investigates the importance of the K-T approach in the modelling of pressure cracked structures. T-stress is the constant in the second term of the Williams expression; it is often negligible, but recent literature has shown that there are cases where T-stress plays the role of opening the crack, also T-stress improves elastic modeling at the point of crack. In this research study, the most important effects of the T-stress are collected and analyzed. A numerical analysis was carried out by the extended finite element method (X-FEM) to analyze T-stress in an arc with external notch under internal pressure. The different stress method (SDM) is employed to calculate T-stress. Moreover, the influence of the geometry of the notch on the biaxiality is also examined. The biaxiality gave us a view on the initiation of the crack. The results are extended with a comparison to previous literature to validate the promising investigations.

Into Mesh Lubrication of Spur Gears With Arbitrary Offset Oil Jet. Part 1: For Jet Velocity Less Than or Equal to Gear Velocity

1983 ◽  
Vol 105 (4) ◽  
pp. 713-718 ◽  
Author(s):  
L. S. Akin ◽  
D. P. Townsend
Keyword(s):  
Inclination Angle ◽  
Gear Tooth ◽  
Optimum Operating ◽  
Spur Gears ◽  
Optimum Operating Condition ◽  
Operating Condition ◽  
The Common ◽  
Jet Velocity ◽  
Oil Jet

An analysis was conducted for into mesh oil jet lubrication with an arbitrary offset and inclination angle from the pitch point for the case where the oil jet velocity is equal to or less than pitch line velocity. The analysis includes the case for the oil jet offset from the pitch point in the direction of the pinion and where the oil jet is inclined to intersect the common pitch point. Equations were developed for the minimum oil jet velocity required to impinge on the pinion or gear and the optimum oil jet velocity to obtain the maximum impingement depth. The optimum operating condition for best lubrication and cooling is provided when the oil jet velocity is equal to the gear pitch line velocity with both sides of the gear tooth cooled. When the jet velocity is reduced from pitch line velocity the drive side of the pinion and the unloaded side of the gear is cooled. When the jet velocity is much lower than the pitch line velocity the impingement depth is very small and may completely miss the pinion.

Fatigue crack growth of filament wound GRP pipes with a surface crack under cyclic internal pressure

2008 ◽  
Vol 43 (16) ◽  
pp. 5569-5573 ◽  
Author(s):  
Ahmet Samanci ◽  
Ahmet Avci ◽  
Necmettin Tarakcioglu ◽  
Ömer Sinan Şahin
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Internal Pressure ◽  
Crack Growth ◽  
Surface Crack ◽  
Filament Wound
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