Shakedown and failure of the threaded joints under low cyclic loading

Leonavičius, Mindaugas; Krenevičius, A.

doi:10.1016/s0143-974x(98)80081-3

“…Since resistance of the cracked stud to cyclic loading is mostly predefined by contribution of the stable crack growth, contribution of initial and unstable cyclic cracking stages has been neglected in the below comparison. Prediction of the stud crack growth with it being in the depth of nut for the considered threaded joints M20×2.5 was performed by applying the same principles which were used to describe its fatigue fracture experienced during the conventional low fatigue tests of 31 specimens [20,31]. The results of the quantitative prediction of the ratio N st (z)/N st (z C ) are presented in this Section after clarification of calculation methodology.…”

Section: Prediction Of the Stud's Crack Growth In Depth Of The Nutmentioning

confidence: 99%

“…The Paris equation constants were obtained from the experimental data of 31 conventional fatigue tests of joints M20×2.5, presented in [31], with attention being given to the macrocrack growth stage in the cross-section z C of the stud.…”

Section: Prediction Of the Stud's Crack Growth In Depth Of The Nutmentioning

confidence: 99%

Increasing the cyclic strength of threaded joints through the unloading of cracked sections

Krenevičius

¹

,

Kačianauskas

²

,

Leonavičius

³

et al. 2012

J min metall B Metall

1

0

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The cyclic strength of the axially loaded threaded joints is considered and the procedural method to increase their lifetime through the unloading of cracked sections is presented. The method operates by varying the mutual positions of the stud and the nut. It was shown how to exploit resources of the threaded joint after opening of the crack without reduction of the safety. The developed mathematical model allows control the accumulation of the fatigue damage as well as the crack growth in the roots of the stud thread. Increase of the cyclic lifetime is theoretically evaluated by the ratio of the numbers of loading cycles required to initiate cracks in the roots of unengaged and the most dangerous engaged turns of the stud. Performance of the elaborated technique is demonstrated by considering the crack growth in depth of the nut. The relative safety of the unloaded cross-sections containing cracks is studied. Comparison of the presented developments with standard safety requirements is presented

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“…Experimental investigation [ 5,13] into threaded joints has shown that in some instances total stresses arising due to tightening and cyclic bending efforts tend to reach the plastic area and even to penetrate to a certain depth. Also, it has been observed that following a small number of cycles and subsequent formation of a favourable field of residual stresses, cyclic plastic strains fail to accumulate, ie shakedown of joints take place.…”

Section: Shakedown Of Threaded Jointsmentioning

confidence: 99%

“…The methods of experimental research included the known approaches [3] and were being constantly improved in order to ensure such a loading of threaded joints tested which corresponds at most to actual working conditions. The analysis of developing the stress state and crack formation presented in the works [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] shows the resistance to cyclic disintegration, the complexity of adaptation process and regularities disclosed by experimental and theoretical research. The present article reviews some peculiarities of investigating and calculating threaded joints stressed, and cyclically tensioned or bended.…”

Section: Introductionmentioning

confidence: 99%

Peculiarities of Calculating the Cyclic Strength of Important Threaded Joints

Leonavičius

¹

,

Krenevičius

²

,

Stupak

³

et al. 2002

Journal of Civil Engineering and Management

0

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The calculation of the strength of important threaded joints is started by defining the minimum size of the cross-section of bolts (studs). Then the static and cyclic strength is tested. The studs of the demountable joints of nuclear power equipment are calculated in accordance with the norms of the Russian Federation and the ASME Code. The calculation methods coincide in essence, they are based on similar limit states; however, there also some differences exist. The authors investigate and compare both methods in their work. There is a brief analysis of calculation methods in the article.For closer definition of standards and their substantiation the authors used experimental and theoretical investigations performed at Laboratory of Strength Mechanics of Vilnius Gediminas Technical University.In order to develop a uniform cyclic strength and shakedown calculation procedure for critical threaded joints, a completely new calculation of a progressive profile change is recommended to be performed before the calculation of cyclic strength. The results have been used in the development of calculation standards for nuclear power equipment, in designing mineral grinding machines and evaluating their residual resource.

show abstract

“…The methods of experimental research included the known approaches [3] and were being constantly improved in order to ensure such a loading of threaded joints tested which corresponds at most to actual working conditions. The analysis of developing the stress state and crack formation presented in the works [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] shows the resistance to cyclic disintegration, the complexity of adaptation process and regularities disclosed by experimental and theoretical research. The present article reviews some peculiarities of investigating and calculating threaded joints stressed, and cyclically tensioned or bended.…”

Section: Introductionmentioning

confidence: 99%

Peculiarities of Calculating the Cyclic Strength of Important Threaded Joints

Leonavičius

¹

,

Krenevičius

²

,

Stupak

³

et al. 2002

Journal of Civil Engineering and Management

0

View full text Add to dashboard Cite

The calculation of the strength of important threaded joints is started by defining the minimum size of the cross-section of bolts (studs). Then the static and cyclic strength is tested. The studs of the demountable joints of nuclear power equipment are calculated in accordance with the norms of the Russian Federation and the ASME Code. The calculation methods coincide in essence, they are based on similar limit states; however, there also some differences exist. The authors investigate and compare both methods in their work. There is a brief analysis of calculation methods in the article. For closer definition of standards and their substantiation the authors used experimental and theoretical investigations performed at

show abstract

Shakedown and failure of the threaded joints under low cyclic loading

Cited by 9 publications

References 0 publications

Increasing the cyclic strength of threaded joints through the unloading of cracked sections

Increasing the cyclic strength of threaded joints through the unloading of cracked sections

Peculiarities of Calculating the Cyclic Strength of Important Threaded Joints

Peculiarities of Calculating the Cyclic Strength of Important Threaded Joints

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