YS-STS-BS-04

BOLT GROUP ANALYSIS

Problem

Design bolted connection that meant to resist the following forces:

93kN shear in x direction (in-plane), 21kN shear in y direction (in-plane), 0kNm torsion (in-plane), 60kN tension (out-of-plane), 18.1kNm bending moment about x-x axis (out-of-plane) and 54kNm bending moment about y-y axis (out-of-plane).

Use steel grade S355 and bolt class 8.8.

Solution

1. Set the bolt diameter, edge distance of bolt group and ply thickness.
2. Determine the number of bolt and bolt group geometry.
3. Calculate the centre of gravity of bolt group.
4. Calculate the second moment of area of bolt group about x-x and y-y axes. Then, sum them up to obtain polar moment of inertia of bolt group.
5. Determine the induced in-plane moment due to eccentricity of in-plane forces (shear in x and y directions).
6. Calculate the resultant in-plane force developed in each bolt.
7. Calculate the resultant out-of-plane force developed in each bolt.
8. Determine the shear capacity of bolt based on Table 30 & cl.6.3.2.1, BS5950-1:2000.
9. Determine the bearing capacity of bolt based on Table 31, Table 32 & cl.6.3.3, BS5950-1:2000.
10. Determine the tension capacity of bolt based on Table 34 & cl.6.3.4.2, BS5950-1:2000.
11. Evaluate the bolt design by determining the capacity ratio for shear, bearing and tension.
12. For bolts subjected to both shear and tension, determine the capacity ratio in accordance with cl.6.3.4.4, BS5950-1:2000.