Page 237 - Handbook of Structural Steel Connection Design and Details

Welded Joint Design and Production

222 Chapter Three

penetration (PJP) groove welds frequently are used for static struc-
tures. In dynamic structures subject to many compression cycles, CJP
groove welds often are required for fatigue reasons.
In theory, compression joints require no welds, providing the base
metals will bear on another bearing surface. Some horizontal shear-
ing forces may be present and the use of a weld with a throat equal to
50% of the base metal thickness is common.

3.6.5 Practical approach to determine weld
size for bending or torsional loads
The following is a simple method to determine the correct amount of weld-
ing required for adequate strength for a bending or torsional load. This is a
method in which the weld is treated as a line, having no area, but a defi-
nite length and outline. This method has the following advantages:
1. It is not necessary to consider throat areas because only a line is
considered.
2. Properties of weld are easily found from a table without knowing
weld leg size.
3. Forces are considered on a unit length of weld instead of stresses,
thus eliminating the knotty problem of combining stresses.
4. Actual test values of welds are given as force per unit length of
weld instead of unit stress on throat of weld.

3.6.6 Treat weld as a line
Visualize the welded connection as a single line, having the same out-
line as the connection, but no cross-sectional area. Notice (Fig. 3.20)

Figure 3.20 Treating weld as line.

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