8/10/2019 Practise Set

1/1

1.A double riveted lap joint is made between 15 mm thick plates. The rivet diameter and

pitch are 25 mm and 75 mm respectively. If the ultimate stresses are 400 MPa in

tension, 320 MPa in shear and 640 MPa in crushing, find the minimum force per

pitch which will rupture the joint. If the above joint is subjected to a load such thatthe factor of safety is 4, find out the actual stresses developed in the plates and the

rivets.

2. Find the efficiency of the following riveted joints : (1). Single riveted lap joint of 6

mm plates with 20 mm diameter rivets having a pitch of 50 mm., (2). Double riveted

lap joint of 6 mm plates with 20 mm diameter rivets having a pitch of 65 mm.

Assume Permissible tensile stress in plate = 120 MPa, Permissible shearing stress inrivets = 90 MPa,Permissible crushing stress in rivets = 180 MPa.

3.Two plates of 10 mm thickness each are to be joined by means of a single riveteddouble strap butt joint. Determine the rivet diameter, rivet pitch, strap thickness andefficiency of thejoint. Take the working stresses in tension and shearing as 80 MPa

and 60 MPa respectively.

4.A double riveted double cover butt joint in plates 20 mm thick is made with 25 mmdiameter rivets at 100 mm pitch. The permissible stresses are t= 120 MPa, = 100

MPa and c= 150 MPa. Find the efficiency of joint, taking the strength of the rivet in

double shear as twice than that of single shear.

5.Find the following for a double riveted lap joint with chain riveting for plates of

20mm thick taking allowable values of stress in shear, tension and compression equal

to 60 MPa, 90MPa &120 MPa respectively. i) Rivet diameter ii) longitudinal pitch

iii) Transverse pitch.

6.Design a double riveted lap joint with zig zag riveting for 13mm thick plate. Take

strength in tension, shear and compressive respectively as 80, 60 and 120 MPa. Find

the efficiency of the joint.

7. Design a double riveted butt joint with two cover plates for the longitudinal seam of a

boiler shell 1.5 m in diameter subjected to a steam pressure of 0.95 N/mm2. Assume

joint efficiency as 75%, allowable tensile stress in the plate 90 MPa; compressivestress 140 MPa; and shear stress in the rivet 56 MPa.

8. It is required to design the longitudinal rivet joint for a boiler of inner diameter 1.5m.the steam pressure in the boiler is 2 MPa. The longitudinal joint is triple riveteddouble cover plate butt joint of unequal width. The pitch in the outer row is twice the

pitch of rivets in inner rows. The efficiency of the joint is 82%. Assume the rivets in

double shear are 1.875 times stronger than in single shear. The allowable stresses inshear and crushing of rivets are 60 MPa and 120 MPa respectively. Tensile stress for

material of plate = 80 MPa.