Question 1                                                                                                                 

Find the allowable tensile force that the multiple bolted structural joint shown in figure (a) and (b) below can transmit. Also find the efficiency of the joint.

The plates are 250 mm wide and 20 mm (main plate) and 12 mm (cover plates) thick.

The bolts are 19 mm in diameter.

The allowable stresses are 140 MPa in tension, 70 MPa in shear and 340 MPa in bearing.

Question 2                                                                                                                 

Determine the proper lengths of the welds for the connection of a 76 x 51 x 11.1 mm steel angle to a steel plate as shown in the figure below.

The connection is to develop the full strength in the angle uniformly stressed to 140 MPa.

Use 10 mm fillet welds (distance of centre of gravity of angle taken from shorter leg is 26.9 mm).

Question 3

A solid steel bar of circular cross section has diameter d = 40 mm, length L = 1.3 m and shear modulus of elasticity G = 80 GPa. The bar is subjected to torques T acting at the ends.

(a)        If the torques have magnitude T = 340 N.m, what is the maximum shear stress in the bar? What is the angle of twist between the ends?                                                                     

(b)        If the allowable shear stress is 42 MPa and the allowable angle of twist is 2.5o, what is the maximum permissible torque?       

 

Question 4                                                                                                                 

A cantilever beam having stepped moment of inertia is subjected to a 4 kN load at the free end as shown in the figure. Using moment area theorems, evaluate the slope and deflection at the free end.

E = 204 x 10⁶ kN/m²

Question 5A spherical tank of diameter 1.2 m and wall thickness 50 mm contains compressed air at a pressure of 17 MPa. The tank is constructed of two hemispheres joined by a welded seam as shown in the figure.

(a)        What is the tensile load f (N per m length of the weld) carried by         the weld?                                                          

(b)       What is the maximum shear stress τ_max in the wall of the tank?

                                                                                    

(c)        What is the maximum normal strain ε in the wall?

(assume E = 210 GPa, v = 0.29)