Strength of Combined Parallel & Transverse Fillet Weld Video Lecture | Design of Machine Elements - Mechanical Engineering

Hello Friends here in this video we will
see what is meant by Strength of
Transverse Fillet Weld in this here I
would be deriving a formula of strength
strength means load carrying capacity
for a transverse fill it well but for
that purpose I have to draw a diagram so
let us get started
Here I am having two plates one is the
upper plate
and other is the lower plate now these
two plates they are connected with the
help of a welded joint
here this indicates the joint that it is
welded
now when these two blades are connected
there will be force acting on the upper
plate next force acting on the lower
plate because of the action of these two
forces this joint it can break now for
this joint we need to know that how much
value of load this joint can resist and
that is nothing but the strength of
transverse fill it will for this fill it
way we should know how much is the load
carrying capacity so what we can do here
is I'll assume that this thickness of
the plate is s and similarly upper plate
will also have the same thickness so
here I will say that first of all let s
be the thickness of plate in mm
next after this I'll say that L be the
length of weld this will also be in mm
now this joint which we are saying which
is the welded joint I can simplify this
that is here it is having a diagram like
this now what we can do here is join
these two points so that we get a right
angle triangle and here I will call it
as triangle ABC this extra portion is
nothing but it is called as
re-enforcement this is a reinforcement
which is provided for added strength so
when we are analyzing the transverse
fill it well we need to know that year
there is a right angle triangle now this
triangle has two sides one is a B
next is BC
both of them are of same height that is
s which we can call it as the plate
thickness now from B I will draw a
perpendicular line on this hypotenuse AC
this hypotenuse where it meets diapered
aeneas this perpendicular I will call it
as M next angle B a.m. that will be
equal to 45 degree now this distance BM
is called as throat thickness I will
write down BM it is called as throat
thickness and throat thickness is the
minimum thickness I will write down that
it is minimum thickness
in the world
so when we have this minimum thickness
and this thickness would be carrying on
up to the entire length length of weld
is L so I will be getting an area now
this is the area on which welding is
done where I will see that this is T
throat thickness and here we have length
of weld so this is the minimum area now
remember that either we talk about
welded joint or we'll talk about any
object it will always fail at the
minimum area in a welded joint minimum
area will be at the throat because at
throat the thickness is minimum so
therefore minimum area at the throat
that will be a is equal to T into L now
how to get T here if we can see in this
triangle a MB which I can draw it here
in an enlarged way
this is a MB now this BM indicates the
throat thickness T a B indicates the
thickness of plate which is s this angle
is 45 degree so from this I can say that
since sine 45 degree is equal to
opposite upon hypotenuse opposite is T
iPod anuses s so therefore T is equal to
sine 45 into s so finally t will be sine
45 is point seven zero seven into s so
we can put this value of T to get the
minimum area so I will say that
therefore minimum area of weld capital A
that will be equal to t which is 0.7 0.7
0 7 s multiplied by the length of weld L
now after getting this minimum area I
can say that
therefore the tensile strength because
transverse fill it when it is subjected
to tensile load so tensile strength of
transverse fill it weld it will be given
by P is equal to area multiplied by
tensile stress
so therefore P will be equal to area is
0.7 0 7 s multiplied by L into Sigma T
this I will keep it as equation number 1
now your I will say that in equation
number 1 equation 1 gives the strength
or load carrying capacity of single
transverse
fill it weld now suppose we have another
fill it will at the bottom like I can
mark it here that here there is another
fill it well so I'll say that after this
for double transpose fill it wait
area will be twice of throat thickness
multiplied by L that is a previous area
which we were getting as T into L here
since we will be using to fill it
transverse fill it well so area is 2
into T into L so this will be 2 into T
is 0.7 0 7 s multiplied by L so hence
area will be 1 point 4 1 4 s into L this
is the area which we will get for double
transverse fill it will after this we
can say that there for strength or load
carrying capacity of double transfers
fill it weld that load carrying capacity
will be denoted by P and again this will
be Sigma T into a that is tensile stress
into area because transverse phillyd
field they are subjected to tensile load
so therefore P is equal to area first I
will write down one point four one four
into s multiplied by L into Sigma T this
I will keep it as equation number two so
therefore from equation number two
strength of double transverse fill it
well
can be found out so you're in this video
we have seen how to know calculate or
how to derive the formula of strength of
transverse fill it way we had started it
from a diagram we had seen what is meant
by throat thickness which is the minimum
thickness then minimum area which is
throat thickness into L so after getting
this area we had even converted the
value of T in the form of s so T was 0.7
ZZ 0 7 s with the help of this diagram
it was explained then finally we were
getting minimum area of well then
tensile strength of transverse fill it
well which was single so here in
equation 1 we were getting the strength
equation for load carrying capacity of
single transverse fill it will and
similarly we had gone on to deriving the
area and the formula for double
transverse pellet weld so in this video
we have seen how to get the strength of
transverse fill it went