Birla Institute of Technology (BIT Mesra) 2007 B.E Design of Steel Structures - Question Paper

BIRLA INSTITUTE OF TECHNOLOGY AND SCIENCE, PILANI
FIRST SEMESTER 2007 – 2008
Comprehensive exam (open book)
Design of Steel Structures
Course No: CE C381 Date: 13-12-2007
Duration: three hrs. Max. Marks: 100 (40 %)
Note: The needed values can be taken from Handouts and Code Book.
(Only textbook, Class notes, Handouts, Code books are allowed.)

1. A double cover butt joint is used to connect plates of 10 mm thick, design the riveted joint and determine its efficiency. Use 20 mm power driven rivets. Take permissible axial tension in plate = 0.6 fy where fy = 250 MPa. Take permissible stresses for shear and bearing for shop rivets are 100 MPa and 300 MPa. [8]

2. a) Two plates of 12 mm thickness, grade 43 steel, are connected together by 20 mm diameter bolts. Assuming that the edge distances are greater than the 1.25 D and two D respectively. compute the strength of 1 bolt in the joint. The grade of bolt is 8.8 with the threads in shear plane. [7]

b) A Tee- part is a part of a beam-to stanchion connection which is needed to transfer 320 kN in tension and 120 kN in shear. Check if 4 8.8 grade steel and 20 mm diameter bolts will be adequate, assuming the plates are 12 mm thick. Use Limit State Method [5]

3. An I-section is built up by welding a 200 x 10 mm web plate to 2 150 mm x 10 mm flange plates by 10 mm thick fillet welds. obtain out the maximum shearing force which may be permitted if the mean shearing stress in the web and the maximum shear stress in weld are not to exceed 100 MPa. [5]

4. A single unequal angle 125 x 75 x eight mm is connected to a 10 mm thick gusset plate at the ends with four Nos of 20 mm diameter bolts to transfer tension. Determine the design tensile strength and also the efficiency if 2 such angles are connected to the identical side of the gusset through 125 mm leg. Take edge distance as 30 mm. The yield and ultimate strength of the steel used are 250 MPa and 420 MPa respectively. Use LSM. [15]

5. Design the vertical member (which can carry axial force, shearing force and bending moment) whose 1 end is free and other end is fixed, having 3.53 m length and carries factored load of 1863 kN axially. Take E = 200 GPa, fy = 250 MPa and ?m = 1.15. Use Limit State Method. [15]

6. Design a suitable rolled I beam for the subsequent Figure 1. Take E = 200 GPa, fy = 250 MPa. presume stiff support bearing of 75 mm. Take the value of design compressive stress in web from Chapter 10 of Handout. Check for torsional buckling is not necessary. All loads provided in the figure are factored loads. Use Limit State Method. [15]










Figure 1

7. a) The propped Cantilever beam shown in Figure two is made of a part with a plastic moment Mp. Determine the collapse load, Wc. [8]


Figure 2

b) Determine the shape factor of the T-Section. The properties of the T-Section are provided beneath. [5]
Width of flange 100 mm,
Thickness of flange 10 mm
Thickness of web 10 mm and the
Height of web 190 mm

c) Find the collapse load for the propped cantilever beam with central point load using kinematic method [7]

8) Design a bolted end plate connection ranging from an ISMB 400 beam and an ISHB 200 @ 37.3 kg/m so as to transfer a hogging factored bending moment of 100 kN-m and a vertical factored shear of 100 kN. Use HSFG bolts of diameter 20 mm. Use Limit State Method [10]

Earning:   Approval pending.