Design of Bolted

Joints

Design of Laterally Unrestrained Beams Design of Steel Structures to EC3

Page(2) Dr.Mamoun Alqedra Eng.Mohammed AbuRahma Eng. Haya Baker

5.1 Summary

Design of Laterally Unrestrained Beams Design of Steel Structures to EC3

Page(3) Dr.Mamoun Alqedra Eng.Mohammed AbuRahma Eng. Haya Baker

Design of Laterally Unrestrained Beams Design of Steel Structures to EC3

Page(4) Dr.Mamoun Alqedra Eng.Mohammed AbuRahma Eng. Haya Baker

Design of Laterally Unrestrained Beams Design of Steel Structures to EC3

Page(5) Dr.Mamoun Alqedra Eng.Mohammed AbuRahma Eng. Haya Baker

Design of Laterally Unrestrained Beams Design of Steel Structures to EC3

Page(6) Dr.Mamoun Alqedra Eng.Mohammed AbuRahma Eng. Haya Baker

Design of Laterally Unrestrained Beams Design of Steel Structures to EC3

Page(7) Dr.Mamoun Alqedra Eng.Mohammed AbuRahma Eng. Haya Baker

5.2 Solved Problems

Problem (1)

A UB 610 x 229 x 125 is used as a tension member and is connected to two 10 mm

gusset plates as shown below. S355 steel is used for tension member and the gusset

plate. The member has been designed to resist a tension factored load , = 4000 KN.

Use full thread bolts M20 8.8 bolts in four lines, two in each flange as shown below.

Design the tension member and the bearing type connection.

Solution:

- Design Loads = 4000 KN.

- Section Properties, 159 , 19.6 , b 229mm

- Bolt data, M20, class 8.8, 20 2 22

640 ⁄ , 800 ⁄ , 314 , 245 ,

- Material Properties, 345 ⁄ , 490 ⁄

1. Design of tension member

- ,

.

10 5485.5 4000

- 159 10 4 22 19.6 14175.2

- , . . .

.10 5001 4000 .

- So, the member is satisfactory.

2. Design of connection

3. Shear Resistance design of M20 bolts.

- ,. ∗ ∗

.94.08

- No. of bolts =, .

42.51 44

4. Assume bolts layout for 44 bolts 11 bolts in each line

- Minimum spacing limits

1.2 ∗ 22 26.4 50

2.2 ∗ 22 48.4 50

2.4 ∗ 22 52.8 129

Design of Laterally Unrestrained Beams Design of Steel Structures to EC3

Page(8) Dr.Mamoun Alqedra Eng.Mohammed AbuRahma Eng. Haya Baker

5. Bearing resistance for end bolts

- min 2.8 ∗ 1.7 2.5 min 6.36 2.5 2.5

- min∗

1 min 0.757 1.63 1 0.757

- ,. ∗ . ∗ ∗ ∗

.148.48

6. Bearing resistance for inner bolts

- min 1.4 ∗ 1.7 2.5 min 8.2 2.5 2.5

- min∗

1 min 0.507 1.63 1 0.507

- ,. ∗ . ∗ ∗ ∗

.99.37

7. Bearing design resistance for 44 bolts

4 ∗ 148.48 40 ∗ 99.37 4568.72 4000

8. Check Long Joint

- Limiting 15 ∗ 15 ∗ 20 300

- Available 10 ∗ 50 500

- 1∗

0.95

- Design shear resistance = ∗ ∗ ,

- 0.95 ∗ 44 ∗ 94.08 3932.54 4000 →

- Try using 48 bolts in four lines 12 bolt in each line

- Limiting 15 ∗ 15 ∗ 20 300

- Available 11 ∗ 50 550

- 1∗

0.9375

- Design shear resistance = ∗ ∗ ,

- 0.9375 ∗ 48 ∗ 94.08 4233.6 4000 →

9. Check Block shear for one gusset plate

- 129 22 ∗ 10 1070

- 2 ∗ 11 ∗ 50 50 22 ∗ 11.5 ∗ 10 6940

- , ,

√

- ∗

. √

∗ 1801.78

- For both gusset plate =2*1801.78=3603.57 KN <4000 KN Not Ok.

Design of Laterally Unrestrained Beams Design of Steel Structures to EC3

Page(9) Dr.Mamoun Alqedra Eng.Mohammed AbuRahma Eng. Haya Baker

Try increasing

10. Bearing resistance for inner bolts

- min 1.4 ∗ 1.7 2.5 min 8.2 2.5 2.5

- min∗

1 min 0.909 1.63 1 0.909

- ,. ∗ . ∗ ∗ ∗

.178.16

11. Bearing design resistance for 48 bolts

4 ∗ 148.48 44 ∗ 178.16 8432.96 4000

12. Check Long Joint

- Limiting 15 ∗ 15 ∗ 20 300

- Available 11 ∗ 60 660

- 1∗

0.91

- Design shear resistance = ∗ ∗ ,

- 0.91 ∗ 48 ∗ 94.08 4109.41 4000 →

13. Check Block shear for one gusset plate

- 129 22 ∗ 10 1070

- 2 ∗ 11 ∗ 60 50 22 ∗ 11.5 ∗ 10 9140

- , ,

√

- ∗

. √

∗ 2234

- For both gusset plate =2*2234=4468 KN >4000 KN Ok.

Extra Ideas

- Use more line of bolts on web.

- Try using Slip resistance connection.

- Using M22 bolts.