Residual stress effects on fatigue life prediction using hardness measurements for butt-welded joints made of high strength steels

Abstract

The fatigue resistance of welded connections made of high strength steel (HSS) is one of the most important topics for the application of HSS in the construction sector. One of the most challenging issues is how to predict the fatigue life of welded structures with complex geometry based on the test results from relatively simple coupon specimens. However, there are generally pre-existing residual stresses in the welded coupon specimens during fatigue tests, and these residual stresses vary greatly in welded structures with complex geometry. This increases the difficulty in predicting the fatigue behaviour of welded structures based on results at coupon scale. Hence, it is important to establish a relationship between the residual stress independent material characteristics and fatigue life. The fatigue behaviour of complex welded structures can be predicted by this residual stress independent material characteristics calibrated at the coupon level and simulated local residual stress distribution. In this paper, the residual stress-free characteristics, hardness, is employed to predict the fatigue life of butt-welded joints. Besides, the residual stress of V-shaped butt welds on a plate made of high strength steels are analysed by modelling of the welding process based on subsequent thermal analysis and mechanical stress analysis by implementing kill/birth strategies. The results show that it contributes to a better prediction compared with experimental results after considering the residual stress effects.

A State‐of‐Art Review on Prediction Model for Fatigue Performance of Welded Joints via Data‐Driven Method

“…[22][23][24][25][26][27][28] Due to size effect, most of the samples used in fatigue tests are small-sized samples, and the smallsized samples are difficult to fully reflect the stress concentration and stress gradient of the actual structures, leading to difficulties in understanding the relationship between IFs and fatigue properties. [29,30] Although various classical methods have achieved fruitful results, these methods usually adopt some simplified assumptions, [31,32] which make it difficult to fully consider the impact of comprehensive factors on fatigue performance; thus, a general method for variable service conditions is required. With the data explosion, data-driven methods have been applied to various industries, and the advantages of data-driven method in induction and summary of data lead to the reliable analysis and prediction of fatigue properties.…”

Numerical Simulation and Experimental Measurement of Residual Stresses in a Thick-Walled Buried-Arc Welded Pipe Structure

“…It is generally known that this phenomenon leads to the appearance of undesirable effects such as changes in the crystal structure, changes of mechanical properties in the weld zone and the occurrence of permanent plastic deformations and residual stresses [1][2][3][4]. Plastic deformations disrupt the external appearance and cause dimensional deviations which is a problem when assembling pipe structures, while on the other hand, residual stresses contribute to the appearance of cracks and generally shorten the life of the welded structure [5,6]. Although there are effective thermal [7,8] and mechanical [9,10] procedures for the removal of residual stresses and plastic deformations in engineering practice, their application is often limited by the size of the structure, large number of welds, operating conditions and additional financial costs.…”

Mechanical behaviour of welded high strength steel rectangular hollow section joints

“…The high strength steel (HSS) benefits long-span and high-rise structures in civil engineering sector, such as sports arenas and bridges [1][2][3][4][5]. Tubular structures are generally recommended for such high-rise and long-span structures [6].…”