Residual Stress Relief in 2219 Aluminium Alloy Ring Using Roll-Bending

Relieving the residual stress in components is essential to improve their service performance. In this study, a roll-bending process was proposed to reduce the quenching residual stress in a large-size 2219 Al alloy ring. The roll-bending effect on quenching residual stress was evaluated via the finite element method (FEM) combined with experiment. The effect of radial feed quantity, friction coefficient, and roller rotational speed during the roll-bending process on quenching residual stress was analyzed. A set of optimized roll-bending parameters with radial feed quantity, friction coefficient, and roller rotational speed was obtained. The results reveal that the best reduction rates of circumferential and axial residual stress reached 61.72% and 86.24%, respectively. Furthermore, the difference of the residual stress reduction effect between the roll-bended ring and the three-roller bended beam was analyzed.

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Evolution of Stress and Strain in 2219 Aluminum Alloy Ring During Roll-Bending Process

10.21203/rs.3.rs-801258/v1 ◽

2021 ◽

Author(s):

Hai Gong ◽

Hua Tang ◽

Tao Zhang ◽

Fei Dei ◽

Xiaolong Liu ◽

...

Keyword(s):

Residual Stress ◽

Aluminum Alloy ◽

Stress Distribution ◽

Stress Reduction ◽

Large Scale ◽

Stress And Strain ◽

Winding Number ◽

Roll Bending ◽

Bending Process ◽

2219 Aluminum Alloy

Abstract The large quenched residual stress of large-scale aluminum alloy ring component induces severe deformation in the subsequent maching process. The conventional methods for reduction of residual stress (such as stepwise cold pressing and bulging) have little effect in the residual stress reduction for large-scale ring component and will induce inhomogeneous stress distribution. In this paper, roll bending process is adopted to reduce the quenched residual stress of 2219 aluminum alloy super-large ring. The numerical model of roll bending process was established, and the evolution and distribution of stress and strain after roll bending were studied. The influence of roll winding number on the uniformity of stress and strain was analyzed. The results show that the arch-shaped quenched residual stress of the ring changes to N-shaped distribution from inside to outside after roll bending process. The value of the residual stress reduces from ±180MPa in quenched state to the value within ±50MPa in roll bended state. With the increase of roll winding number, the stress uniformity is improved, but the stress reduction amplitude is basically the same. By analyzing the elastic-plastic strain distribution characteristics and strain springback law of the ring after roll bending, the formation mechanism of N-shaped residual stress distribution after roll bending is revealed.

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Effects of Hybrid Structures on the Stress Reduction and Thermal Properties of Joints in Electronics Devices

Materials Science Forum ◽

10.4028/www.scientific.net/msf.879.1258 ◽

2016 ◽

Vol 879 ◽

pp. 1258-1264

Author(s):

Michiya Matsushima ◽

Noriyasu Nakashima ◽

Satoshi Nishioka ◽

Shinji Fukumoto ◽

Kozo Fujimoto

Keyword(s):

Thermal Expansion ◽

Epoxy Resin ◽

Stress Reduction ◽

Analytical Study ◽

Coefficient Of Thermal Expansion ◽

Conductive Adhesives ◽

Silicon Chips ◽

Composite Joint ◽

The Difference ◽

Reduction Effect

Electronics devices consist of silicon chips, copper leads, resin or ceramics substrates and which are jointed to each other with solder, conductive adhesive or other materials. Each coefficient of thermal expansion is different and it causes strain concentration and cracks. The solder easily deformed by the difference of the thermal expansion and it relieved the stress on the devices however the epoxy resin of the conductive adhesives are harder. So we suggested the composed joint including the relaxation layers of low elastic material. The shear strength and elongation of the epoxy resin joint, silicone rubber joint and the composite joint of the two materials were investigated. The analytical study was carried out to clarify the stress reduction effect of the design of the relaxation layer in the composite joints. The parameters such as the width, height, pitch and the distance of the relaxation layer from the joint edge are investigated. The high relaxation layer close to the joint edge effectively reduced the stress of the joint. The stress reduction effect appeared in the different pitch of the layers.

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Measurement of Residual Stress in Railway Wheels With Vertical Split Rim Failures

ASME 2012 Rail Transportation Division Fall Technical Conference ◽

10.1115/rtdf2012-9422 ◽

2012 ◽

Author(s):

Adrian T. DeWald ◽

Scott Cummings ◽

John Punwani

Keyword(s):

Residual Stress ◽

Residual Stresses ◽

Failure Mode ◽

Low Cycle Fatigue ◽

Growth Failure ◽

Crack Face ◽

Axial Residual Stress ◽

Class C ◽

The Difference ◽

Railway Wheels

Residual stresses are known to significantly impact the initiation and growth of cracks in metallic components such as railway wheels. Tensile residual stresses are of particular concern due to their ability to non-conservatively affect performance. Vertical split rim (VSR) is an important failure mode for railway wheels. Vertical split rim, like any crack growth failure mode, is significantly influenced by residual stress (e.g., mean or steady stress effects). The crack face of a typical VSR wheel shows signs of low-cycle fatigue. Recently, residual stress measurements were performed on a set of Class C railway wheels. This study looked at the difference in axial residual stress for wheels in three primary conditions: new (as manufactured), service-worn, and wheels that failed through VSR. Residual stresses were significantly larger in the service-worn condition and for wheels that had failed due to VSR relative to the new condition. There is a small difference in the axial residual stress profiles of wheels that failed due to VSR compared to other service-worn wheels. It is unclear, however, if the difference is significant based on a limited population of data. This paper provides a description of the methods used to quantify residual stress in the Class C railway wheels and presents important results from the study.

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Non-Destructive Measurement of Residual Stresses in U-0.8 WT% Ti by Neutron Diffraction

MRS Proceedings ◽

10.1557/proc-166-305 ◽

1989 ◽

Vol 166 ◽

Author(s):

A. Salinas-Rodriguez ◽

J.H. Root ◽

T.M. Holden ◽

S.R. Macewen ◽

G.M. Ludtka

Keyword(s):

Residual Stress ◽

Neutron Diffraction ◽

Residual Stresses ◽

Wall Thickness ◽

Radial Stress ◽

Biaxial Stress ◽

Axial Residual Stress ◽

Residual Strains ◽

The Difference ◽

Hoop Stresses

ABSTRACTThe macroscopic residual stress distribution in γ-quenched and stress levelled U-0.8wt% Ti alloy tubes was studied using neutron diffraction techniques. Residual strains were evaluated from the difference in d-spacings measured in the tubes and in small reference samples machined from each tube. Residual stresses were calculated with the isotropic bulk values of the elastic constants for polycrystalline α-U. Quenching from the γ field resulted in a nearly equi-biaxial stress state at every point across the wall thickness of the tube. The magnitude of the radial stress was very small compared with that of the axial and hoop stresses which were compressive at the surfaces and tensile in the interior. Stress levelling relieved almost completely the hoop residual stress without affecting the radial stress. The axial residual stress becomes tensile through the wall thickness and remains constant at about 20% of its magnitude in the as-quenched condition.

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TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170876 ◽

1994 ◽

Vol 52 ◽

pp. 628-629

Author(s):

J. Fang ◽

H. M. Chan ◽

M. P. Harmer

Keyword(s):

Residual Stress ◽

Single Phase ◽

Stress Relief ◽

Stress Recovery ◽

Surface Residual Stress ◽

Microscopic Mechanism ◽

Sic Particles ◽

Annealing Procedure ◽

The Difference ◽

Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

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Case study: Prediction and field tests of railway noise and effects of a low-height noise barrier

Noise Control Engineering Journal ◽

10.3397/1/376826 ◽

2020 ◽

Vol 68 (4) ◽

pp. 303-314

Author(s):

Yuna Park ◽

Hyo-In Koh ◽

University of Science and Technology, Transpo ◽

...

Keyword(s):

High Speed ◽

Field Tests ◽

Residential Areas ◽

Railway Systems ◽

Railway Noise ◽

Sound Levels ◽

Noise Barrier ◽

The Difference ◽

Reduction Effect ◽

The Impact

Railway noise is calculated to predict the impact of new or reconstructed railway tracks on nearby residential areas. The results are used to prepare adequate counter- measures, and the calculation results are directly related to the cost of the action plans. The calculated values were used to produce noise maps for each area of inter- est. The Schall 03 2012 is one of the most frequently used methods for the production of noise maps. The latest version was released in 2012 and uses various input para- meters associated with the latest rail vehicles and track systems in Germany. This version has not been sufficiently used in South Korea, and there is a lack of standard guidelines and a precise manual for Korean railway systems. Thus, it is not clear what input parameters will match specific local cases. This study investigates the modeling procedure for Korean railway systems and the differences between calcu- lated railway sound levels and measured values obtained using the Schall 03 2012 model. Depending on the location of sound receivers, the difference between the cal- culated and measured values was within approximately 4 dB for various train types. In the case of high-speed trains, the value was approximately 7 dB. A noise-reducing measure was also modeled. The noise reduction effect of a low-height noise barrier system was predicted and evaluated for operating railway sites within the frame- work of a national research project in Korea. The comparison of calculated and measured values showed differences within 2.5 dB.

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Low-pressure turbine disc fi rtree slots’ life and reliability enhancement by ultrasonic surface hardening

10.36652/1813-1336-2020-16-11-491-495 ◽

2020 ◽

pp. 491-495

Author(s):

A.M. Tomashevich ◽

G.G. Shirvan’yants ◽

D.A. Teryaev

Keyword(s):

Residual Stress ◽

Low Pressure ◽

Fatigue Tests ◽

Compression Stress ◽

Cycle Basis ◽

Low Pressure Turbine ◽

Working Stress ◽

Turbine Disc ◽

Axial Residual Stress ◽

Reliability Enhancement

The possibility of life and reliability enhancing of AL-31F low pressure turbine disc’s fir-tree slots by ultrasonic hardening is considered. Having disc’s material properties studied, working stress derivation is executed which was further used for following comparative fatigue tests. Also, Davidenkov method residual stress analysis is carried out which showed 95.3 % change to compression stress for circumferential residual stress and 80.9 % change to compression stress for axial residual stress which proves possibility of fir-tree slots’ life and reliability enhancement by ultrasonic hardening. Comparative fatigue tests with N = 4•10 5 cycles basis showed that the hardened samples standing out the cycle basis during higher oscillatory amplitudes (and, thus, affecting loads) than the non-hardened basic ones.

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