Comparison of numerical and ultrasonic techniques for quantifying interference fit pressures

In railway transportation, the press fit of wheel and axle is typically causing fretting damage and it is also an important issue relative to the safety of railway. To examine the fretting damage of the interference fit of wheel and axle the fretting fatigue test under 4-point rotating bending loads is carried out based on samples, as well as the fretting fatigue damage rule is studied. The test results show that the fretting causes the fatigue limit to decrease significantly and all of the fracture sections occur at the contact edges of the fitting zone with the sleeve.

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A New Look at Subcritical Quenching (SCT) for Fatigue Strength Improvement

Journal of Engineering for Industry ◽

10.1115/1.3439363 ◽

1977 ◽

Vol 99 (4) ◽

pp. 867-874

Author(s):

H. R. Neifert

Keyword(s):

Fatigue Strength ◽

Large Forging ◽

Press Fit ◽

Service Information ◽

Fatigue Strength Improvement ◽

The Press ◽

Rotating Bending ◽

Compressive Residual Stresses ◽

Strength Improvement ◽

Comprehensive Reference

A comprehensive summary of in-house information concerned with thermal prestressing of large forgings for fatigue strength improvement is presented. Seven commercial grades of carbon and alloy steel railway forgings with and without a subcritical quenching treatment (SCT) are compared. Conventional designs of full-size press-fitted assemblies and a filleted shaft were tested in rotating bending to evaluate the treatment. Fatigue strength improvement values ranging from 45 to over 130 percent have been established for breaking off in the wheel fit, depending upon the yield strength of the shaft material and the configuration at the press fit. Compressive residual stresses induced by the treatment were measured for most materials, and in some instances the loss of surface compression due to cyclic stressing was evaluated. An example of practical use of the information summarized is cited by a discussion of the application of SCT in the development of a tubular axle for transit car service. Information being presented in this paper updates published literature with current technology pertinent to the application of thermal prestressing to a variety of large forging materials. It provides a comprehensive reference background to substantiate and stimulate greater use of the treatment by others confronted with the design of fatigue resistant assemblies.

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Analysis of Interference-Fit Joints

Applied Sciences ◽

10.3390/app112311428 ◽

2021 ◽

Vol 11 (23) ◽

pp. 11428

Author(s):

Jerzy Madej ◽

Mateusz Śliwka

Keyword(s):

Bearing Capacity ◽

Load Capacity ◽

Fem Simulation ◽

Load Bearing Capacity ◽

Measuring Device ◽

Plastic Deformations ◽

Interference Fit ◽

Load Bearing ◽

Press Fit ◽

The Press

Interference fit joints have been widely used in many engineering constructions, in particular in electric motors. It is of particular importance to calculate the load capacity of press-fit joints, especially in the overload ranges of construction to estimate the safety factor. The article presents a FEM numerical simulation of pressing the shaft into the hub, taking into account various types of fits. The results of numerical simulations presented in the article were positively verified with the MTS measuring device, which confirmed the correctness of the numerical model. So far, the load-bearing capacity of press-fit joints has been calculated from Lame’s formulas. The results of the load capacity of the joints obtained by the FEM simulation were compared with the results obtained from Lame’s formula. The comparison shows that when designing interference fit joints, attention should be paid to the fact that the press-in process, depending on the type of fit, may be elastic-plastic. Plastic deformations in the contact zone of the joint affect its load-bearing capacity. Therefore, the design of press-fit joints should not be based on Lame’s formulas, which do not take into account the range of plastic work of the material.

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Measures to Counter Fatigue Failure in Railway Axles

Journal of the Institution of Locomotive Engineers ◽

10.1243/jile_proc_1968_058_022_02 ◽

1968 ◽

Vol 58 (322) ◽

pp. 136-171 ◽

Cited By ~ 1

Author(s):

W. W. Maxwell ◽

B. R. Dudley ◽

A. B. Cleary ◽

J. Richards ◽

J. Shaw

Keyword(s):

Marked Reduction ◽

Fatigue Cracks ◽

Fatigue Cracking ◽

Fatigue Tests ◽

Press Fit ◽

Cold Roll ◽

Stress Relieving ◽

The Press ◽

Rotating Bending ◽

Limited Service

This paper reviews the experience in London Transport of fatigue cracking in railway axles, and presents the results of laboratory fatigue tests on full-scale axle specimens under simulated rotating bending. The investigation was undertaken with the aim of entirely eliminating fatigue cracking and fretting under the press fits of wheel-axle sets. Whilst cold rolling of wheel seats, which is standard L.T. practice, strongly inhibits the propagation of such fatigue cracks, it does not prevent their initiation. The introduction of a stress-relieving groove, such that the edge of the press fit overhangs the groove, leads to a marked reduction in fretting and increase in life of test specimens, and the results of a limited service test suggest that the presence of such a groove reduces the stresses under the wheel hubs to a level at which cracking is eliminated. Since the presence of a press fit near to a groove increases the stress level at the root of the groove it is desirable to cold-roll the grooves, and a suitable rolling technique employing three rollers of slightly different profile radii has been developed.

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IMPROVEMENT OF DETAILS CONNECTION ASSEMBLY TECHNOLOGY WITH INTERFERENCE

Bulletin Samara State Agricultural Academy ◽

10.12737/18678 ◽

2016 ◽

Vol 1 (2) ◽

pp. 30-34

Author(s):

Коновалов ◽

Vladimir Konovalov ◽

Симанин ◽

Nikolay Simanin ◽

Петрова ◽

...

Keyword(s):

Fluid Pressure ◽

Hydraulic Cylinder ◽

Machine Building ◽

Technical Solution ◽

Mechanical Assembly ◽

Interference Fit ◽

Press Fit ◽

Axial Forces ◽

The Press ◽

Assembly Technology

The purpose of the study is to increase the strength of the collected compounds and to expand the technological accuracy of the method of Assembly with an interference fit. Fixed press-fit connection with interference are widely used in machine building, when the transfer of substantial axial forces are required, torques or combined loads from their joint action. Resistance to mutual misalignment of the parts in these compounds is created and supported by the forces of elastic deformation on the mating surface of the covered part (shaft) and stretching on the mating surfaces of the covering parts (holes) is proportional to the magnitude of the preload in the connection. In such compounds, the diameter of the shaft before Assembly is always larger than the diameter of the hole. In the article the analysis of the known different ways of joining parts with interference fit, including hydraulic presses. The second problem is solved due to the fact that the connection details with tightness is carried out by pressing the press stroke from one detail to another, and the breakdown of the compounds obtained by the relative longitudinal movement of parts, in which the breakdown is carried out periodically in the process of pushing through the transfer of force from the press stroke to pressed items to the elastic connection. The force on the press stroke is created by a hydraulic cylinder with large displacement, a resilient connection between the slider and pressed item performs in the cylinder, the fluid pressure and volume which can be adjusted by changing the stiffness and capacity of the drive RAM, as well as the magnitude of its longitudinal movement during the disruption. The scheme of Assembly of the connection de-hoist with tension. Original technical solution for press fit connection parts extends the technological possibilities of the equipment, increases the strength of the collected compounds and can be used in machine building, particularly in mechanical Assembly processes and, in particular, in the repair and production of agricultural machinery.

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Measures to Counter Fatigue Failure in Railway Axles

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1967_182_014_02 ◽

1967 ◽

Vol 182 (1) ◽

pp. 89-108 ◽

Cited By ~ 19

Author(s):

W. W. Maxwell ◽

B. R. Dudley ◽

A. B. Cleary ◽

J. Richards ◽

J. Shaw

Keyword(s):

Marked Reduction ◽

Fatigue Cracks ◽

Fatigue Cracking ◽

Fatigue Tests ◽

Press Fit ◽

Cold Roll ◽

Stress Relieving ◽

The Press ◽

Rotating Bending ◽

Limited Service

This paper reviews the experience in London Transport of fatigue cracking in railway axles, and presents the results of laboratory fatigue tests on full-scale axle specimens under simulated rotating bending. The investigation was undertaken with the aim of entirely eliminating fatigue cracking and fretting under the press fits of wheel-axle sets. Whilst cold rolling of wheel seats, which is standard L.T. practice, strongly inhibits the propagation of such fatigue cracks, it does not prevent their initiation. The introduction of a stress-relieving groove, such that the edge of the press fit overhangs the groove, leads to a marked reduction in fretting and increase in life of test specimens, and the results of a limited service test suggest that the presence of such a groove reduces the stresses under the wheel hubs to a level at which cracking is eliminated. Since the presence of a press fit near to a groove increases the stress level at the root of the groove it is desirable to cold-roll the grooves, and a suitable rolling technique employing three rollers of slightly different profile radii has been developed.

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Auszugverhalten von Schaftfräsern*/Pull-out behavior of end mills – Experimental study on different clamping devices with various clamping mechanisms

wt Werkstattstechnik online ◽

10.37544/1436-4980-2018-05-79 ◽

2018 ◽

Vol 108 (05) ◽

pp. 353-358

Author(s):

E. Abele ◽

F. Ali ◽

M. Berger

Keyword(s):

Experimental Study ◽

Test Bench ◽

Mechanical Load ◽

Mechanisms Of Action ◽

Heavy Duty ◽

Press Fit ◽

Pull Out ◽

The Press ◽

End Mills ◽

Tool Position

Aus Schwerzerspanung und Turbinenschaufelfertigung ist bekannt, dass Werkzeuge aus dem Spannfutter ausgezogen werden. Die veränderte Werkzeugposition führt zur Abweichung von den vorgegebenen Toleranzen und einer geringeren Fertigungsqualität oder Beschädigung des Werkstücks. Der Artikel untersucht das Auszugsverhalten verschiedener Spannfutter. Mit einem Prüfstand können die Einflüsse der mechanischen Belastung und der Klemmlänge auf die Haltekraft im Pressverband betrachtet und die Wirkmechanismen beim Auszug des Werkzeuges aus dem Spannfutter sensorisch ermittelt werden.   From heavy-duty cutting and turbine blade manufacturing it is known that tools pull out from chucks. A change in tool position leads to deviations from tolerance and decreases manufacturing quality or damages the workpiece. This article explores the extension behavior of different chucks on a specifically designed test bench. This allows determining how mechanical load and clamping length influence the holding force in the press fit and what mechanisms of action affect the extraction of the tool from the chuck.

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Fatigue Strength Analysis and Fatigue Damage Evaluation of Roller Chain

Metals ◽

10.3390/met8100847 ◽

2018 ◽

Vol 8 (10) ◽

pp. 847 ◽

Cited By ~ 3

Author(s):

Ryoichi Saito ◽

Nao-Aki Noda ◽

Yoshikazu Sano ◽

Jian Song ◽

Takeru Minami ◽

...

Keyword(s):

Fatigue Crack ◽

Fatigue Strength ◽

Fatigue Damage ◽

Fatigue Crack Initiation ◽

Strength Analysis ◽

The Finite Element Method ◽

Roller Chain ◽

Press Fitting ◽

The Press ◽

Static Tensile

This paper deals with the roller chain commonly used for transmission of mechanical power on many kinds of industrial machinery, including conveyors, cars, motorcycles, bicycles, and so forth. It consists of a series of four components called a pin, a bush, a plate, and a roller, which are driven by a sprocket. To clarify the fatigue damage, in this paper, the finite element method (FEM) is applied to those components under three different types of states, that is, the press-fitting state, the static tensile state, and the sprocket-engaging state. By comparing those states, the stress amplitude and the average stress of each component are calculated and plotted on the fatigue limit diagram. The effect of the plastic zone on the fatigue strength is also discussed. The results show that the fatigue crack initiation may start around the middle inner surface of the bush. As am example, the FEM results show that the fatigue crack of the inner plate may start from a certain point at the hole edge. The results agree with the actual fractured position in roller chains used in industry.

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