Influence of Geometry and Residual Stress on Fatigue of Welded Joints

Selby, K.A.; Stallmeyer, J.E.; Munse, W.H.

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https://hdl.handle.net/2142/14054 Copy

Description

Title

Influence of Geometry and Residual Stress on Fatigue of Welded Joints

Author(s)

• Selby, K.A.
• Stallmeyer, J.E.
• Munse, W.H.

Issue Date

1965-06

Keyword(s)

• Residual stress
• Welded joints -- Fatigue.

Abstract

The purpose of this investigation was to study the factors which contribute to the relatively low fatigue strength of welded joints in high strength steel subjected to low mean stress and a large number of cycles. Fatigue tests were conducted on axially loaded specimens containing a double V butt-weld. A number of test series were devised to separate the effects of geometry and residual stress. The significance of weld geometry was investigated by machining unwelded specimens to weld-like contours. Fatigue tests revealed that the geometry of the weld was extremely important at all levels of stress which were studied, If small irregularities or weld undercuts existed they could initiate premature failures. The stress concentration values of the weld reinforcement were evaluated by several methods including an equivalent shear method which is based primarily on the geometric properties of the weld reinforcement. The influence of residual stress was studied by comparing the fatigue results of as-welded, stress relieved and unwelded specimens with the same geometry. Fatigue failures tended to initiate in regions of maximum tensile transverse residual stress. Estimates of the maximum stress at the toes of a weld revealed that this stress is approximately equal to the yield stress even when the maximum nominal stress is the fatigue limit. By subjecting the edges of the weld reinforcement to lateral pressure both the notch geometry and the residual stress pattern were altered. This process resulted in an increase in the fatigue strength.

Publisher

University of Illinois Engineering Experiment Station. College of Engineering. University of Illinois at Urbana-Champaign.

Series/Report Name or Number

Civil Engineering Studies SRS-297

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/14054

Sponsor(s)/Grant Number(s)

National Steel Corporation

Owning Collections