A Virtual Tool for Wear Simulation of Plastic Gear Pairs

2013 ◽  
Author(s):  
F. Karpat ◽  
S. Ekwaro-Osire ◽  
C. Yüce ◽  
E. Karpat
Keyword(s):  
Analytical Approach ◽  
Failure Modes ◽  
Wear Behavior ◽  
Load Capacity ◽  
Tooth Wear ◽  
Wear Depth ◽  
Spur Gears ◽  
Automotive Applications ◽  
Wear Model ◽  
Plastic Gears

Currently plastic gears are widely used in industry, and not only for lightly loaded applications like household appliances, tools, and toys, but also in the more demanding areas of machinery in automotive applications. However there is a need to investigate important properties such as load capacity, endurance, cost, life, stiffness and wear. Tooth wear is one of the major failure modes in plastic gears just like with steel gears. This paper focuses on the simulation of wear for standard and non-standard gears using an analytical approach. A numerical model for wear prediction of gear pairs is developed. A wear model based on Archard’s equation is employed to predict wear depth. The variation of the contact load generated by the cumulative tooth profile wear is simulated and examined. A MATLAB-based virtual tool is developed to analyze wear behavior of standard and non-standard spur gears depending on various gear parameters. In this paper, this virtual tool is introduced with numerical examples.

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.

Wear of Involute Spur Gears With Asymmetric Teeth Under Dynamic Loading

Tribology ◽  
2006 ◽  
Author(s):  
F. Karpat ◽  
S. Ekwaro-Osire
Keyword(s):  
Aerospace Industry ◽  
Tooth Wear ◽  
Wear Depth ◽  
Spur Gears ◽  
Contact Ratio ◽  
Mesh Stiffness ◽  
Wear Model ◽  
Extreme Performance ◽  
Gear Contact ◽  
The Relationship

Spur gears with asymmetric teeth have a significant potential for some applications requiring extreme performance like in the aerospace industry. In this study, the influence of tooth wear on the dynamic behavior of involute spur gears with asymmetric teeth is analyzed. The Archard's wear model was adopted in formulating and accounting for wear. Effects of gear parameters such as gear contact ratio, tooth height, mesh stiffness, and pressure angles on tooth wear are considered. These parameters are used to describe the relationship between dynamic tooth load and tooth wear. A comparison of symmetric and asymmetric teeth is also presented with respect to tooth wear. Sample simulation results, which were obtained by using an in-house developed computer program, are illustrated with numerical examples. The numerical results match well with the practical and analytical results which are available in literature. For asymmetric teeth, it was shown that the wear depth decreased with increasing pressure angle on drive side.

A Prediction Method of Wear on Tooth Surface for Spur Gears

2013 ◽  
Author(s):  
Shotaro Inoue ◽  
Kiyotaka Ikejo ◽  
Kazuteru Nagamura ◽  
Natsuhiko Seyama ◽  
Shinya Nakagawa
Keyword(s):  
Failure Modes ◽  
Gear Tooth ◽  
Testing Machine ◽  
Prediction Method ◽  
Tooth Wear ◽  
Spur Gear ◽  
Tooth Surface ◽  
Wear Depth ◽  
Spur Gears ◽  
Gear Drives

Gear drives are widely used in various mechanical systems. Therefore, the understanding for the failure mode of gear tooth provides the improvement of various machines. The wear on the tooth surface is one of the important failure modes for the gear drives. The tooth wear changes its profile, and frequently increases gear vibration and noise. However, there are many unclear phenomena about the wear on the tooth surface for the gear drive. In this study, we investigated wear of spur gear using a power circulating-type gear testing machine, and measured the change in tooth profile of the test gears. Furthermore, we developed a computer program to predict the amount of the wear on the tooth surface for the spur gears. The method employs two equations. One is based on the wear theory under lubricated condition that was deduced by Soda. The other is derived from the ploughing wear model. Using these equations, the wear depth on the tooth surface is calculated with the contact stress, the sliding velocity, the oil film thickness, etc. The calculated value of the wear agreed with the experimental data.

scholarly journals Wear of Spur Gears Having a Dithering Motion and Lubricated With a Perfluorinated Polyether Grease

2007 ◽  
Author(s):  
Timothy Krantz ◽  
Fred Oswald ◽  
Robert Handschuh
Keyword(s):  
Wear Rate ◽  
High Speed ◽  
Failure Modes ◽  
Load Level ◽  
Wear Depth ◽  
Spur Gears ◽  
Test Load ◽  
Total Wear ◽  
Gear Contact ◽  
Perfluorinated Polyether

Gear contact surface wear is one of the important failure modes for gear systems. Dedicated experiments are required to enable precise evaluations of gear wear for a particular application. The application of interest for this study required evaluation of wear of gears lubricated with a grade 2 perfluorinated polyether grease and having a dithering (rotation reversal) motion. Experiments were conducted using spur gears made from AISI 9310 steel. Wear was measured using a profilometer at test intervals encompassing 10,000 to 80,000 cycles of dithering motion. The test load level was 1.1 GPa maximum Hertz contact stress at the pitch-line. The trend of total wear as a function of test cycles was linear, and the wear depth rate was approximately 1.2 nm maximum wear depth per gear dithering cycle. The observed wear rate was about 600 times greater than the wear rate for the same gears operated at high speed and lubricated with oil.

Development of a Dynamometer to Study the Performance of Plastic Gears

2007 ◽  
Author(s):  
Mike Cassata ◽  
Martin Morris ◽  
Jorge Abanto-Bueno
Keyword(s):  
High Speed ◽  
Failure Modes ◽  
Gear Tooth ◽  
Digital Camera ◽  
Operating Conditions ◽  
Spur Gears ◽  
Camera System ◽  
Dupont Company ◽  
Plastic Gears ◽  
Flank Surface

A testing facility has been developed to explore the failure modes of plastic gears. The overall goal is the prediction of gear tooth failure for a given set of operating conditions and to classify failure modes of plastic gears. The initial investigation is centered on the testing of plastic spur gears placed on a parallel-shaft drive train between a variable-speed, reversible DC motor and an eddy current dynamometer. The testing apparatus has been designed, fabricated, and refined to deliver consistent results. The dynamometer places two plastic spur gears in mesh, one being the drive gear and the other the driven. Most of the test gear pairs were injection molded, 40-tooth, 0.8 module gears. These gears were molded using Delrin™ 311DP, a polyoxymethylene polymer which is made by the DuPont Company. Optical encoders were attached to the input and output shafts to sense the shaft position providing a measurement of the deflection and wear of the gear teeth. In addition, an infrared temperature sensor was retrofitted to the dynamometer apparatus to measure the tooth-flank surface temperature. All of the tests where the gear flank temperature reached 250°F resulted in a catastrophic failure. The apparatus was also fitted with a high-speed digital camera system capable of sampling 1000 frames per second. The camera recorded the failure of the plastic gears.

Load Testing to Collapse Limit State of Barr Creek Bridge

2000 ◽  
Vol 1696 (1) ◽  
pp. 92-102 ◽  
Author(s):  
Nicholas Haritos ◽  
Anil Hira ◽  
Priyan Mendis ◽  
Rob Heywood ◽  
Armando Giufre
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Flexural Rigidity ◽  
Load Capacity ◽  
Limit State ◽  
Dynamic Test ◽  
Service Condition ◽  
Flat Slab ◽  
Testing Program ◽  
Static Testing

VicRoads, the road authority for the state of Victoria, Australia, has been undertaking extensive research into the load capacity and performance of cast-in-place reinforced concrete flat slab bridges. One of the key objectives of this research is the development of analytical tools that can be used to better determine the performance of these bridges under loadings to the elastic limit and subsequently to failure. The 59-year-old Barr Creek Bridge, a flat slab bridge of four short continuous spans over column piers, was made available to VicRoads in aid of this research. The static testing program executed on this bridge was therefore aimed at providing a comprehensive set of measurements of its response to serviceability level loadings and beyond. This test program was preceded by the performance of a dynamic test (a simplified experimental modal analysis using vehicular excitation) to establish basic structural properties of the bridge (effective flexural rigidity, EI) and the influence of the abutment supports from identification of its dynamic modal characteristics. The dynamic test results enabled a reliably tuned finite element model of the bridge in its in-service condition to be produced for use in conjunction with the static testing program. The results of the static testing program compared well with finite element modeling predictions in both the elastic range (serviceability loadings) and the nonlinear range (load levels taken to incipient collapse). Observed collapse failure modes and corresponding collapse load levels were also found to be predicted well using yield line theory.

scholarly journals Simulation and Experimental Study on Wear of U-Shaped Rings of Power Connection Fittings under Strong Wind Environment

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 735
Author(s):  
Songchen Wang ◽  
Xianchen Yang ◽  
Xinmei Li ◽  
Cheng Chai ◽  
Gen Wang ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
Adhesive Wear ◽  
Surface Hardness ◽  
Wear Depth ◽  
Strong Wind ◽  
Wear Model ◽  
Wind Environment ◽  
Simulation Results ◽  
Oxidation Wear ◽  
Good Agreement

The objective of this study was to investigate the wear characteristics of the U-shaped rings of power connection fittings, and to construct a wear failure prediction model of U-shaped rings in strong wind environments. First, the wear evolution and failure mechanism of U-shaped rings with different wear loads were studied by using a swinging wear tester. Then, based on the Archard wear model, the U-shaped ring wear was dynamically simulated in ABAQUS, via the Umeshmotion subroutine. The results indicated that the wear load has an important effect on the wear of the U-shaped ring. As the wear load increases, the surface hardness decreases, while plastic deformation layers increase. Furthermore, the wear mechanism transforms from adhesive wear, slight abrasive wear, and slight oxidation wear, to serious adhesive wear, abrasive wear, and oxidation wear with the increase of wear load. As plastic flow progresses, the dislocation density in ferrite increases, leading to dislocation plugs and cementite fractures. The simulation results of wear depth were in good agreement with the test value of, with an error of 1.56%.

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