so we've got some young engineers here
today on my left side we have austin and
one more right side we have
and they're here because we've got
something really special from brazil
it's a product produced by mola
it came in this giant box an engineering
kit that is not only just for the young
engineers but also the older engineers
like me let's just have a look at what
they sent me
you see it comes with this fascinating
kit it comes with springs
ties
and magnets
and what engineer doesn't love magnets
so send this first kit here that allows
you to do more of that stability you can
see it's got cross bracing
and from walls and diaphragm forces look
at our second kit here
that helps you visualize some of those
criticals create connections and
buckling actions
and then we've got our third kit which
is the one they're actually looking for
that we'll keep all the way to the end
which is tension time bridges and we're
gonna be building this bridge now i do
have to mention something they did send
it to me for free but this was in
exchange for this review and me using it
in my videos however they don't have any
control of what i say or what i say in
this review so this is all my own words
my name is brendan your structural
engineer now let's get into it let's get
into it let's get into it now we'll
start with this first kit here which
comes with this magnetic tray and all
these other magnets we're going to build
it up quickly but let's build this first
one and see what we can find and some of
the structural dynamics that we can
learn
see now this is the first part so we
built our columns up we've got our
column bases we have these little
triangle pits here that allows us to
mimic column fixity so you snap in here
allows us to make that commonphilic city
when we push it on the back it just
slides over when we go to the front of
the front with the column fixity we can
see we're getting bending actions so we
can either choose a pin connection
or a fish connection for these type of
connections now let's keep building
see this kit also has these tyres so
these are no good in compression
but they're really good in tension
so we can use them to mimic cross
bracing in a building
and so now we've got this piece here
this piece is going to act more like
your slab diaphragms you see it's a nice
rigid piece and it still snaps in with
those magnets
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now we can do something fascinating with
this one
we've got cross-spacing on one side
yet we've got a moment frame in the long
direction so we push the short direction
we can see it's really rigid but if you
push the long direction we can see we
can push it over
and it waves backwards and forwards you
can see that oscillation that we see
inside building so if we've got an
earthquake we can see
we can get really funky shapes with how
the building is behaving under an
earthquake
you can see it shakes backwards and
forwards but there's one ways that we
can deal with this firstly we can create
more rigid connections so we can put
cross bracing at the bottom here which
i'll add in later what you can also do
is add dampening to the top of the
building and stop this way now if we
just do this one test let's watch how it
rocks backwards and forwards and watch
how long it takes for that oscillation
to stop however there's a really simple
way that we can stop the oscillation and
that's through just adding a little bit
of water on the top now what this does
is helps can balance some of that load
so i've got a tub of water we'll add it
to the top we'll see what happens
to the sway the building
add it to the top
now all we're going to do is push it now
watch this
you see how much slower it is let's try
again we'll push it over we can see it
stops that sway do you know why
because
it's heavy and it's making it stop but
what happens is in the water as you rock
backwards and forwards the brave wing of
that water kind of balances that load so
once we put up there do you want to push
it and try
okay okay you want to try as well
you can push a little bit more
see how it works but if we do the same
thing now you try and push it the same
way as what you just did
see how much more it oscillates so when
we put that water on top and we see the
earthquake that we had before
we can see
that it does not shake as much where
before when we're shaking it
we can see
so much more
but however if it goes off to the side
we can see we get a big collapse so that
wasn't because of the waters because the
weight and the failing of the diaphragm
but we can see that's a good example if
we don't have a good connection of the
diaphragms we'll have a catastrophic
failure so that's another reason why you
need to have a good connection to your
diaphragms now let's pack this up and
move on to the next kit if you're
interested to pick up one of these kits
i'm going to fill in links in the below
description it doesn't cost you any more
but it helps support my channel
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now let's bring out model kit two which
is all about the buckling forces and
we've got some tie actions as well but
we'll be doing more of that buckling
assessment that we can see here now
before we go too far this probably do
point out that it also does come
with these handy manuals about some of
the things that you can do as well we're
going to build this one quickly
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when i add up
i just worked every day and struck
engineering
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we've finished this one and we'll see
we've got a bracing frame we've got a
columns we've got a buckling we're also
this one that's providing moment fixty
in through here we'll snap that in place
this is a really good one to show the
different buckling shapes and how if we
move a buckling shape how it affects the
design of the column
so we'll take off this bottom one now
we'll put some cross bracing in there a
little bit later
but if we watch now
if you push down on this column what do
you think is going to happen when i
press down uh it will fall
it might have fall
oh it does fall
why don't we get some fixity at the base
fix it so we can see it actually snapped
at midpoint
but we probably also need to get some
more fixity
around the midpoint to try and get that
bending moment capacity up
well let's get rid of the pin connection
at the base again
you can see how it's just bowing out in
one direction can you see that
but now watch what happens
when we just get a little bit of central
diaphragm fixity
we'll get the model back into place
we'll mimic what we would get if we've
got a cross bracing in the diaphragm so
add some tension ties in there as well
so now when we try and press it what do
you think is going to happen
let's try
and say so when you see that see how
we're getting the double s curvature
can you see that how it makes an s shape
where before it wasn't an ester it
wasn't it was more like a c
this shape means you've got
double curvature and because of that
double curvature
gives you a lot of additional capacity
out of that column so we can see just
the basic of how we get fixity on a
floor how can help
use we can see now it's only bending in
one direction yeah there's a lot more
stronger and that's why the height of
the column really matters and getting
that fixity through a connection helps
us and that's why we can have a reduced
buckling links okay guys now we're going
up to the epic one we're going to build
a bridge are we excited
yes
now there's a couple of things with the
bridge it gets a little bit more complex
and i've had to do a little bit of setup
to make sure it's done in sufficient
time but you have these big string of
balls and you know you don't need to
worry
you have more than enough so so i've got
leftovers here that i've got for a
different build i've also got this
additional leftover and you're using
this cutter to cut them out
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here we need
the triangle
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oh
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and then we're going to balance them out
so they're
at the same height
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so they've been there because the
problem is about see how it's way so we
also need to cross-brace the bridge
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is that cool got the bridge so do you
know how the bridge is working so it's
got this tension tie so you've got the
cable that comes all the way down here
so what's happening
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is we've got the tension coming in here
so the tension comes up here the tension
tied up so you see this is in tension
you see if we move it watch
you push it here we'll see how the
bridge moves
because it's in tension it makes it
taller so the more we tension we can get
into it
the more tension we can get out of the
system you see we balance it out as well
and see how we've
moved each part to try and be even so
now the bridge is nice and flat right
and when we push it
see it's stable because the cross
bracing's helping us
it's still good enough it's still
working
see
if we took your cross bracing out
now try
it's very wobbly right
back in
because we're forming up the truss
now so we can see we've got quite a high
quality everything's made out of metal
we've got a little bit of plastics here
in the balls but there's a high quality
you could have anything in the office if
you need to teach some architects about
some structural mechanics teaching your
kids
maybe don't do such a big session like
we did they got a little bit tiresome by
the end but it's really enjoyable for
them to play with actual structural
mechanics and learning the structures
behind it if you want to learn a little
bit more about structural engineering
there's probably one thing you may not
know that's really simple that every
engineer should know and i'll have the
link to the video here if you want to
support the channel there's two ways
that you can do this there's either a
link to my patreon or you can become a
youtube member without the support of my
youtube members or patreons this type of
content would not be possible and as
stay always and keep going bye guys
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