The Paton Welding Journal, 2016, №10



2016 №10 (02)

DOI of Article 10.15407/tpwj2016.10.03

2016 №10 (04)

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The Paton Welding Journal, 2016, #10, 14-19 pages
 

Prediction of limiting amplitudes of cycle stresses of welded joints with steady residual stresses

V.A. Degtyarev

G.S. Pisarenko Institute for Problems of Strength, NASU 2 Timiryazevskaya Str., 01014, Kiev, Ukraine. E-mail: ips@ipp.kiev.ua
 
 
Abstract
In the work the method for determination of diagrams of limiting amplitudes of the cycle of welded joints with steady residual tensile stresses is proposed based on the results of tests of small specimens, which can be considered as an express method for calculation of characteristics of fatigue resistance of welded joints when there is no possibility to carry out full-scale investigations and the appropriate computational dependences are presented. The analysis of literature data for different types of welded joints showed satisfactory correlation of experimental and calculated values of fatigue limits of welded joints of low-carbon and low-alloyed steels of a low strength. It was established that all the diagrams of limiting amplitudes of the cycle of welded joints with steady residual stresses are finished on the line, where each point at different mean stresses of the cycle corresponds to the minimum limiting amplitude of the cycle of welded joint with its value of limiting steady residual stress, which provides realization of limiting stresses of cycle. It was shown that if at the low values of steady residual stresses the relative reduction in fatigue limits of butt welded joints of steels of different strength is occurred almost for the same value, then with their increase, the reduction of fatigue limit of steel with higher mechanical characteristics is more significant. 23 Ref., 1 Table, 3 Figures.
 
Keywords: amplitude of cycle stresses, mean stress of cycle, yield strength, steady residual stress, fatigue limit, diagram of limiting amplitudes of cycle
 
 
Received:                10.05.16
Published:               23.10.16
 
 
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