The Paton Welding Journal, 2014, №08



2014 №08 (03)

DOI of Article 10.15407/tpwj2014.08.04

2014 №08 (05)

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The Paton Welding Journal, 2014, #8, 26-32 pages  

EFFECT OF WELD CONVEXITY SIZES ON STRESS STATE OF BUTT JOINT DURING TENSION

G.V. ERMOLAEV, V.A. MARTYNENKO and I.V. MARUNICH

Admiral Makarov National Shipbuilding University. 9 Geroev Stalingrada Ave., 54025, Nikolaev, Ukraine. E-mail: welding@nuos.edu.ua
 
 
Abstract
To find out the possibility of compensation of decreased strength of weld metal by increase in sizes of convexity of butt joint and establishment of dependence of required height of convexity on strength ratio of weld and base metal, the investigation of level and nature of distribution of stresses in butt joints at their tension loading using different sizes of convexities was carried out. The investigations were made by the method of computer modeling on butt joints of C25 and C21 types. Height and width of convexity were varied at constant thickness of base metal. Convexity shape was taken in the form of arc. Fields of all components of stresses, and also their diagrams in different sections of weld were studied. The obtained values of coefficients of concentration (1.8-2.3) in varying the sizes of convexity within the rather wide ranges confirmed the adequacy of modeling. At the same time it was shown that the presence of convexity in symmetric joint of C25 type decreases somewhat the level of maximum tensile and equivalent stresses inside the weld metal, that gives possibility to compensate its strength as compared with base metal, but this decrease is non-proportional to the increase of section area. The expression was obtained, which allows calculating the required value of convexity in joint of C25 type at a known degree of decrease in strength of deposited metal as compared with base metal. The presence of convexities and their size in non-symmetric joint of C21 type does not almost influence the level of maximum equivalent stresses in section along weld axis, therefore it is impossible to compensate the decreased strength of weld metal by increase of convexities in such joint. The obtained results can be used in design of butt joints of materials, in particular high-strength steel joints made by austenitic materials, which encounter problem in providing equal strength of weld and base metal. 12 Ref., 4 Tables, 7 Figures.
 
 
Keywords: butt joint, distribution of stresses, convexity sizes, static loading
 
 
Received:                30.05.14
Published:               28.08.14
 
 
References
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