Steel structures in service condition, such as bridges, offshore-structures and steel towers, are subject to pulsating loads caused by vehiles, waves, current, wind, etc.
“Welding under pulsating loads” cannot be avoided in the case of repair, reinforcement and reconstruction works.
In this study, the deciding method of the initiation of hot crack was investigated by using the results of hot weld crack test under pulsating loads. Moreover, hot crack was considered from a mechanical point of view.
The main results are as follows;
(1) The equation for the initiation condition of hot crack under pulsating loads was shown. Moreovere, based on it, the equation to decide the initiation of hot crack was also shown, in which relative root gap opening displacement, Δδ, that can easily measured before welding was used as a practical mechanical measure.
(2) For the case that the uniform loads are applied, the practical deciding equation for the initiation of hot crack was shown in non-dimentional form. Moreover, applying it to the results of hot crack test under pulsating loads, the validity was concretely shown.
(3) The critical strain curve for hot crack of weld metal used in this study was shown.
(4) The concrete procedure to apply the evaluating equation for hot crack was shown. Besides, so far as the evaluating equation proposed in this paper is used, critical strain is not neccessary to be obtaind.
View full abstract