for college work

1. STRUCTURES RAUNAQ CHANDA 2B
160BARCHI007

2. INTRODUCTION
In this presentation I shall explain about structures and its types. I
shall also depict the way to find the centre of gravity of an irregular
shape.

3. WHAT ARE STRUCTURES
Elements that co exist to form something
that could be manmade or naturally
existing is called a structure. Material
structures include man-made objects such
as buildings and machines and natural
objects such as biological organisms,
minerals and chemicals. Abstract
structures include data structures in
computer science and musical form. Types
of structure include a hierarchy (a cascade
of one-to-many relationships), a network
featuring many-to-many links, or a lattice
featuring connections between
components that are neighbors in space.

4. TYPES OF STRUCTURES
Mainly there are 5 distinct types of structures-
1- truss structure
2- cable structure
3- arch structure
4- framed structure
5- surface structure

5. TRUSS
A truss is basically a triangulated system consisting of long straight elements that form a
sturdy structure usually for rooftop, suspended ceilings etc.
Trusses can be made for a long span. They are lightweight and pretty sturdy too.
Trusses are usually constructed as rooftops where rainy climates are involved.
Trusses are used in a broad range of buildings, mainly where there is a requirement for very
long spans, such as in airport terminals, aircraft hangers, sports stadia roofs, auditoriums and
other leisure buildings. Trusses are also used to carry heavy loads and are sometimes used as
transfer structures.

6. CABLE
A cable is a flexible structural component
that offers no resistance when
compressed or bent in a curved shape.
Technically we can say cable has zero
bending rigidity. It can only support
tensile loading.
Cables are often used in engineering
structures for support and to transmit
load from one point to another when
used to support suspension roofs,
bridges and trolley wheels, cables form
the main load carrying element in the
structure.
Suspension bridges that are constructed
using cables have a high strength to

7. ARCH
An arch is a curved structure that spans an
elevated space and may or may not support
the weight above it.
Arches appeared as early as the 2nd
millennium BC in Mesopotamian brick
architecture, and their systematic use started
with the ancient Romans, who were the first to
apply the technique to a wide range of
structures.
An arch is a soft compression form. It can span
a large area by resolving forces into
compressive stresses and, in turn eliminating
tensile stresses. As the forces in the arch are
carried to the ground, the arch will push
outward at the base, called thrust. As the rise,
A masonry arch
1. Keystone 2. Voussoirs
3. Extrados 4. Impost 5. Intrados
6. Rise 7. Clear span 8. Abutment

8. FRAMED
A framed structure is a network of beams and
columns joined up to form the skeleton
framework of the building. The structural
frame carries the total load of the building
and transfers it to the foundation.
Framed structures were a revolution in the
world of construction as it removed the need
of load bearing walls.
Framed structures are easily erected from pre-
made members. These members are easily
connected together in the correct sequence to
form the structural framework. Problems arise
when large members are used and when the
height of the structure makes lifting difficult.
In these situations a crane will be needed to

9. SURFACE
Structures that are usually constructed with a
membrane roof which allows it to transfer
the load via membrane stress is called
surface structures.
Usually the materials used are flexible which
form a tent or air inflated structure. .In both
cases the material acts as a membrane that is
subjected to pure tension.
Surface structures may also be made of rigid
material such as reinforced concrete.
These structures act like cables or arches
since they support loads primarily in tension
and compression with very little bending. In
spite of this, plate or shell structures are
generally very difficult to
analyse, due to the three-
dimensional geometry of their flexible surfac