S
t
r
u
c
t
u
r
e
s
Forces are anything that can deform a body
(static effect) or change its movement
(dynamic effect).
Examples are gravity (weight), forces that move
mechanisms or machines, pressures of fluids,
(gases, steam, water, wind).
3Static Dynamic
S
t
r
u
c
t
u
r
e
s
Load is a force that acts on a structure.
There are two types:
Permanent load.
Variable load.
4
S
t
r
u
c
t
u
r
e
s
Loads that cause internal tensions
S
t
r
u
c
t
u
r
e
s
S
t
r
u
c
t
u
r
e
s
Image Structure Effort
A Cable Traction
B Shock absorber Compression
C Rope guide Traction
AB
C
1
S
t
r
u
c
t
u
r
e
s
D
E
Image Structure Effort
D Column Compression
E Bridge Flexion/Bending
2
S
t
r
u
c
t
u
r
e
s
Image Structure Effort
F Nut Torsion
G Rivet Shear
FG
1
S
t
r
u
c
t
u
r
e
s
Image Effort
1 Traction
2 Flexion/Bending
3 Compression
4 Flexion/Bending
5 Compression
6 Traction
1
S
t
r
u
c
t
u
r
e
s
A structure is the set of elements in an object that
support the effects of the forces that act on it and
transmit them to the ground. The structure
prevents an object from breaking or becoming too
deformed.
S
t
r
u
c
t
u
r
e
s
Natural
Artificial
4
S
t
r
u
c
t
u
r
e
s
The first structures were made of wood,
then man also used stone. Nowadays, we
use concrete and steel aluminum
S
t
r
u
c
t
u
r
e
s
When structures remain upright (steady) and not
tip over or fall down.
The centre of gravity (mass centre) should be
centered on the base and close to the ground; in
that case the structure is stable. (cardboard cdg
experiment)
5
S
t
r
u
c
t
u
r
e
s
Ways to increase stability: (modeling experiment
at the same time)
Adding mass to its base and/or making the base bigger.
Burying its base underground.
Bracing it. Placing some cables (tie rods).
S
t
r
u
c
t
u
r
e
s
Back
S
t
r
u
c
t
u
r
e
s
Back
S
t
r
u
c
t
u
r
e
s
S
t
r
u
c
t
u
r
e
s
When structures resist stresses (forces) without
breaking. (experiment with sticks or sheets of
paper)
The type of material and the shape are very
important to determine its resistance.
Which situation is
more stable?
3
S
t
r
u
c
t
u
r
e
s
Structures are rigid when they aren’t or are slightly
deformed when a force is applied.
The rigidity of a structure is based on triangulation.
6
S
t
r
u
c
t
u
r
e
s
Great amount ofmaterial: rocks, stones,concrete, mortar.Support compression’sefforts & has very fewspaces.
Examples:Walls: Great China Wall
Pyramids
Ancient “Old” temples
Dams
Sea ports
S
t
r
u
c
t
u
r
e
s
Massive structure
S
t
r
u
c
t
u
r
e
s
Massive structure
S
t
r
u
c
t
u
r
e
s
Massive structure
S
t
r
u
c
t
u
r
e
s
Great amount ofmaterial: rocks, stones,concrete, mortar.Support compression’sefforts & has very fewspaces.
Examples:Ancient “Old” temples:
Greek & Roman
S
t
r
u
c
t
u
r
e
s
Lintel structure
S
t
r
u
c
t
u
r
e
s
Built with the arch.The repetition ofarcs are called vaults(Bóveda).Domes CúpulaExamples: cathedrals,Mosques, aqueducts,bridges.
S
t
r
u
c
t
u
r
e
sVaulted structure
S
t
r
u
c
t
u
r
e
s
Vaulted structure
S
t
r
u
c
t
u
r
e
s
Vaulted structure
S
t
r
u
c
t
u
r
e
s
Vaulted structure
S
t
r
u
c
t
u
r
e
s
Vaulted structure(Dome)
S
t
r
u
c
t
u
r
e
s
Vaulted structure(Dome)
S
t
r
u
c
t
u
r
e
s
Made from curved or bent sheets of
metal, plastic or composite materials.
They are used as shells for all types
of objects.
Shell structure or casing structures
S
t
r
u
c
t
u
r
e
s
Rolled and plate structures
S
t
r
u
c
t
u
r
e
s
Rolled and plate structures
S
t
r
u
c
t
u
r
e
s
Rolled and plate structures
S
t
r
u
c
t
u
r
e
s
Rolled and plate structures
Carton of juice, milk, etc
S
t
r
u
c
t
u
r
e
s
Divided into:
Lattice
Triangulated
Suspended
Made fromprofiles tobuiltframework
S
t
r
u
c
t
u
r
e
s
They are used for
constructing majority of
buildings today.
Scaffolding.
Rigid elements made of wood, steel or
other metals, using cement, concrete or
reinforced concrete, forming a rigid grid.
S
t
r
u
c
t
u
r
e
s
Lattice structure
Lattice structure
S
t
r
u
c
t
u
r
e
s
Lattice structure
S
t
r
u
c
t
u
r
e
s
Lattice structure
S
t
r
u
c
t
u
r
e
s
These structures
use metal bars forming
triangles (triangular
shapes).
Oil rig
S
t
r
u
c
t
u
r
e
s
Triangulated
S
t
r
u
c
t
u
r
e
sTriangulatedCrane
S
t
r
u
c
t
u
r
e
s
TriangulatedPylon
S
t
r
u
c
t
u
r
e
s
Based on the use of
cables, braces or tie
rods.
They are used in
bridges and to cover
stadiums and sports
facilities.
S
t
r
u
c
t
u
r
e
s
Suspended
S
t
r
u
c
t
u
r
e
sSuspended
S
t
r
u
c
t
u
r
e
s
Suspended
S
t
r
u
c
t
u
r
e
sSuspended
S
t
r
u
c
t
u
r
e
s
It contains compressed air inside.
It's light and can be dismantled.
Bouncing House
S
t
r
u
c
t
u
r
e
s
Contains three-dimensional triangulated bars and combines
the properties of vaults and bar structures.