Page 131 - Analysis and Design of Machine Elements

Results
Steps Computation Permanent Connections 109
Units
The force causes the shear failure of the rivets at cross section F = 210 kN
3
A−A is obtained from Eq. (5.1) as
d 2 × 20 2
F shear = 2 × [ ]= 2 × × 120 = 75360N
4 4
The force causes the crushing failure of the rivets at cross
section A−A is obtained from Eq. (5.2) as
F =2dt[ ] = 2 × 20 × 10 × 250 = 100000 N
crushing p
The force required for tensile failure at B−B and simultaneous
shear of rivets at cross section A−A is
F = F + F = 180000 + 75360 = 255360 N
tension shear
The load required for tensile failure at B−B and simultaneous
crushing of rivets at cross section A−A is
F = F tension + F crushing = 180000 + 100000 = 280000N
Therefore, the maximum allowable load for the joint is
210 000 N.

Figure E5.2 Solution for Example B A
Problem 5.1.

F l w F

B A

5.2 Welding

5.2.1 Applications, Characteristics and Structure

Welded joints are permanent joints formed by various welding processes involving met-
allurgical bonding of metals. One of the most widely used joining processes is fusion
welding, which fuses the base metal to form welds. During the welding process, local
heat is applied to the work pieces to increase temperature high enough to melt the metal.
The three major types of fusion welding processes are gas welding, arc welding
and high-energy beam welding. Gas welding mainly refers to oxyacetylene welding.
Depending on the method of supplying filler materials and of shielding the molten weld
metal from atmosphere, arc welding includes shielded metal arc welding (SMAW), gas
metal arc welding (GMAW), gas tungsten arc welding (GTAW) and submerged arc
welding (SAW). High-energy beam welding includes electron beam welding and laser
beam welding [7].
Welding is a reliable, efficient and economical joining process for connecting metal
sections, which is widely used in most engineering fields, including the shipbuilding,