1.
TRUSS & FRAME
Course no-CE 416
course title- Prestress Concrete Design Sessinonal
Presented by
MD. Mohotasimur Rahman
ID NO. 10.01.03.040
Course Teachers
Munshi Galib Muktadir
&
Sabreena Nasrin
Lecturer of Civil Engineering Department
Ahsanullah University Of Science And Tecnology
Dhaka, Bangladesh
2.
TRUSS - INTRODUCTION
A truss is a structure composed of members fastened
together in such a way to resist change in shape and it is
rigid structure.
Triangular unit
A truss is a structure comprising one or more
triangular units constructed with straight members
whose ends are connected at joints referred to as nodes.
Its purpose is to support a larger load or span a
greater distance than any individual member from
which the truss may be built
3.
TRUSS – INTRODUCTION CONTINUE
Node
External forces and reactions to those
forces are considered to act only at the
nodes.
Moments
(torques)
are
explicitly
excluded because, and only because, all the
joints in a truss are treated as pin
joint or hinge joint .
Result in forces in the members which
Tie
strut
are either tensile or compressive forces.
4.
PLANE TRUSS VS SPACE TRUSS
Plane Truss
All member of truss and applied load lie
in a same plane.
Space Truss
An elementary space truss consists of 6
members connected at 4 joints to form a
tetrahedron.
In a simple truss, m = 2n - 3 where m
In a simple space truss, m = 3n - 6
is the total number of members and n is the
where m is the number of members and n
number of joints.
is the number of joints.
9.
METHOD OF TRUSS ANALYSIS
Joint Method
Determine the Support Reaction.
Apply Fx = 0 and Fy = 0 to every node and
determine member force
Dismember the truss and create a free-body
diagram for each member and pin.
10.
METHOD OF TRUSS ANALYSIS
Section method
Determine the Support Reaction.
To determine the force in member BD, pass a
section through the truss as shown and create a
free body diagram for the left side.
With
only
three
members
cut
by
the
section, the equations for static equilibrium may
be applied to determine the unknown member
forces, including FBD.
11.
FRAME (INTRODUCTION)
Contain
at
least
one
multi-force
member, i.e., member acted upon by 3 or more
forces.
Frames are designed to support loads and are
usually stationary.
12.
ANALYSIS OF FRAME
A free body diagram of the complete frame is
used to determine the external forces acting on
the frame.
Internal
forces
are
determined
by
dismembering the frame and creating free-body
diagrams for each component.