B1) 20 pts. The thickness of each of the two sheets to be resistance spot welded is 3.5 mm. It is desired to form a weld nugget
1 answer:
Answer:
I = 8975.95 A
Explanation:
Given :
Diameter of the nugget, D = 5.5 mm
Length of the nugget, l = 5.0 mm
Therefore, volume of the nugget,
=
Now, required melting energy, (M.E.) = 9.5 x V
= 9.5 x 118.73
= 1127.95 J
Given efficiency of the heat used from electric energy, η = 1/3
Then actual required energy = ME/η
= 1127.95 / (1/3) = 3383.84 J
We know that, electric energy (EE) =
where, I is current, R is resistance and t is time in seconds.
3383.75 =
I = 8975.95 A
You might be interested in
Answer:
Electroosmotic velocity will be equal to
Explanation:
We have given applied voltage v = 100 volt
Length of capillary L = 5 mm = 0.005 m
Zeta potential of the capillary surface
Dielectric constant of glass is between 5 to 10 here we are taking dielectric constant as
Viscosity of glass is
Electroosmotic velocity is given as
So Electroosmotic velocity will be equal to
Answer:
a) The ductility = -30.12%
the negative sign means reduction
Therefore, there is 30.12% reduction
b) the true stress at fracture is 658.26 Mpa
Explanation:
Given that;
Original diameter = 12.8 mm
Final diameter = 10.7
Engineering stress = 460 Mpa
a) determine The ductility in terms of percent reduction in area;
Ai = π/4( )² ; Ag = π/4(
)²
% = π/4 [ ( ( )² - (
)²) / ( π/4 (
)²) ]
= ( ( )² - (
)²) / (
)² × 100
we substitute
= [( (10.7)² - (12.8)²) / (12.8)² ] × 100
= [(114.49 - 163.84) / 163.84 ] × 100
= - 0.3012 × 100
= -30.12%
the negative sign means reduction
Therefore, there is 30.12% reduction
b) The true stress at fracture;
True stress =
( 1 +
)
is engineering strain
= dL / Lo
= (do² - df²) / df² = (12.8² - 10.7²) / 10.7² = (163.84 - 114.49) / 114.49
= 49.35 / 114.49
= 0.431
so we substitute the value of into our initial equation;
True stress = 460 ( 1 + 0.431)
True stress = 460 (1.431)
True stress = 658.26 Mpa
Therefore, the true stress at fracture is 658.26 Mpa