YS-STS-BS-03

WELD GROUP ANALYSIS

Problem

Design welded connection that meant to resist the following forces:

60kN shear in x direction (in-plane), 35kN shear in y direction (in-plane), 5kNm torsion (in-plane), 28kN tension (out-of-plane), 50kNm bending moment about x-x axis (out-of-plane) and 18.1kNm bending moment about y-y axis (out-of-plane).

Use steel grade S355 and weld class 42.

Solution

1. Set the weld leg.
2. Determine the weld strength based on Table 37, BS5950-1:2000.
3. Determine the weld group geometry. Identify whether each weld is load bearing and then calculate their effective weld length (cl.6.8.2, BS5950-1:2000).
4. Calculate the total effective weld length of the connection.
5. Calculate the centre of gravity of weld group.
6. Calculate the second moment of area of weld group about x-x and y-y axes. Then, sum them up to obtain polar moment of inertia of weld group.
7. Determine the induced in-plane moment due to eccentricity of in-plane forces (shear in x and y directions).
8. Calculate the resultant in-plane stress developed in each critical node of weld group.
9. Calculate the resultant stress developed after considering the out-of-plane forces.
10. Calculate the weld capacity ratio to evaluate the weld design (cl.6.8.7.2, BS5950-1:2000).