This paper presents the results of the following experimental study: the intensity of tensile restraint (R
F) of tack-welded joints and the intensity of bending restraint (K
B) caused by side fillet welding performed as onesided welding, using I-section girders and hollow cylinders as structures.
In this paper, R
F values are defined as the product of the intensity of tensile restraint coefficient (p) and the plate width (h). After tack-welding, p values were measured. Subsequently, welding was conducted: after cooling off, we observed the occurrence with or without cold cracking in the welded joints. The effect of K
F on R
B values and the relationship with the weldment cracking parameter (P
w), etc. were then determined. The major findings of this investigation are as follows.
1) The coefficient p for girders and cylinders is influenced by the geometrical mean thickness among the vertical and horizontal plates; it is influenced not so much by the number of joints as by the location along the wled line.
2) The effect of KB of girders and cylinders on the coefficient p was determined. In other words, the coefficient p in both kinds of models showed a tendency to decrease under the influence of the bending restraint. However, it was observed that even as K
B increases, the p values for the girders and cylinders converge approximately on 8 and 4-5 kN/mm.mm/mm, respectively.
3) The occurrence of cold cracking of girders can be determined by using the relation between P
w and T
cr of butt joints (graph) as R
F increases, even in the case of high K
B values. On the other hand, for cylindrical models, cracks were sometimes observed in the welded joints with relatively small K
B and R
F values; thus, making it very difficult to judge cold cracking from relational graph mentioned above.
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