00:01
We'll be looking at structural analysis.
00:02
Consider the problem before us where we need to determine the magnitude or the forces in the members of this structure as well as their nature.
00:12
We apply the method of joint to solve this problem.
00:15
The convenient place to start from is joint earth.
00:18
However, i want to look at the reactions, okay? the support reactions, okay? so if we take summation of moment, some of moment, sorry take summation of moment about c 0 they're going to arrive at 9 9 times 4 plus arrow reaction at a vertical component or a y okay time 6 minus 15 times 3 equals 0 so we are going to arrive at arrow, vertical component at a, the reaction at a, equal to 15, sorry, 1 .5 kilo muting.
01:32
Then we can just look for using some sort of upward and downward forces, okay, or vertical forces.
01:40
You can have the reaction component at the roller, the vertical, the reaction at the roller, which is vertical at the roller, which is vertical to be one, fifteen, point five.
01:53
Kilo newton okay now we can start from joint f as i said earlier on so if we consider joint f we'll have this one sorry have this force coming down have this force which is naturally coming in from the can see from the diagram okay the forces should be going at the same level that are naturally going in okay that's our assumption and this force is coming out okay f f f f e, force f soft with f e going to e from f.
02:35
It is a joint f.
02:38
Okay, now if we take some function of forces in the horizontal direction, they're going to have 9 plus f e equal to zero.
02:59
So if we solve this out, we are going to have our f source with f e.
03:08
The force going to the member f .e to be equal to minus 9 kilo -newt.
03:17
You can see that this member is negative.
03:19
The force is negative.
03:21
So the member is under compressive, compressive force.
03:30
You can look at, if you look at, you will discover that f source with fa is also a zero, f f a okay is zero i think we'll label that force that f so with f okay you'll give us sorry we didn't this one is f sorts with f f a okay going to be now that force is zero so f sosw f a we'll give you zero okay then we can look at joint d if you look at join d j d i don't have something that look like this okay it's our join d you said the forces should be going out of the join this is f substrate d e and this is f substrate substrite the c going from join d to c all right well from inspection you will just discover that that fde, f .d .e and s source with dc, okay? they are zero as well.
05:15
This s was with de and sos with dc.
05:20
They are zero, okay? so you can just bring that, those on the out.
05:29
So, f source with dc, okay.
05:37
And you solve it at they're going to give you a zero.
05:41
Based on the diagram that's seen here, f source with d .c.
05:52
Sorry, d .e.
05:54
It's going to give you zero.
05:59
Yeah, you look at the horizontal, you look at the, you look at the horizontal component here, summation of fx.
06:14
Okay? right here, you look at summation of fy.
06:31
Okay, it will be zero.
06:36
Then let's consider joint joint c if you look at the joint at joint d you will see that the joints are just two members forming the joint okay and you can see that no there's no external load acting on the joint or reaction component two that's not raising why they are zero okay the reason why they are zero okay so for join d we have sorry join c we have looked at join g already so let's look at join c okay before join c they're gonna have something that look like okay like this this force coming like this coming straight okay so we have this coming from the joint c f coming from the joint c f going to from join c to b to that member c b.
07:59
They will have this force coming in naturally.
08:02
So at 13 .5 that reaction, that support, the reaction at that support will go to between 5.
08:11
18 .5 kilo -newton, okay? and this one, you said the forces should be coming out.
08:20
So, c, e.
08:23
And f, soft, c, b.
08:29
So we'll take.
08:30
Summation of forces.
08:32
I love this one.
08:34
I'll take sumption of forces in the fact this angle...