Analysis of Truss, There are two major methods of analysis for finding the internal forces in members of a truss; the Method of Joints, which is typically used for the case of creating a truss to handle external loads, and the Method of Sections, which is normally used when dealing modifying the internal members of an existing truss.

1. ANALYSIS OF TRUSS
Static Forces

2. • For the equilibrium of structures made of several connected parts, the internal forces as well the external
forces are considered.
• In the interaction between connected parts, Newton’s 3rd Law states that the
forces of action and reaction between bodies in contact have the same
magnitude, same line of action, and opposite sense.
• Three categories of engineering structures are considered:
a) Frames: contain at least one multi-force member,
i.e., member acted upon by 3 or more forces.
b) Trusses: formed from two-force members, i.e.,
straight members with end point connections
c) Machines: structures containing moving parts
designed to transmit and modify forces.

3. WHAT IS A TRUSS?
• A truss is a structure usually consisting of slender members that are connected to each other at the two
ends of each member.
• All members of a truss structure are connected together with pin joints, such that for the purpose of the
design of these structures we assume the joints cannot carry or resist any moments.
• All external loads acting on a truss are assumed to be acting only at the joints, and therefore, all
members of a truss are two-force members
• Most structures are made of several trusses joined
together to form a space framework. Each truss
carries those loads which act in its plane and may be
treated as a two-dimensional structure.

4. WHY MUST WE LEARN TRUSS
ANALYSIS?
• First of all, if we plan to design and build a truss
structure, such as a roof structure for carrying
external loads, we need to find out how much load
is carried by each member of the truss.
• Secondly, in the case of an existing truss structure,
we may need to replace one or a few members. In
this case, we need to find the internal forces carried
by those few members within the truss structure.
In both instances, the objective is to figure out and
decide whether the members can sustain the forces or
not and what size members and what type of cross
sections are required.

5. TYPES OF TRUSSES

6. • A rigid truss will not collapse under
the application of a load.
• A simple truss is constructed by
successively adding two members and
one connection to the basic triangular
truss.

7. ASSUMPTIONS
For truss analysis, it is assumed that:
•Bars are pin-connected.
•Joints are frictionless hinges.
•Loads are applied at the joints only.
•Stress in each member is constant along its length.
The objective of truss analysis is to determine the reactions and member forces. The methods used
for carrying out the analysis with the equations of equilibrium and by considering only parts of the
structure through analyzing its free body diagram to solve the unknowns.

8. TYPES OF TRUSS ANALYSIS
• There are two major methods of analysis for finding the internal forces in
members of a truss; the Method of Joints, which is typically used for the
case of creating a truss to handle external loads,
• and the Method of Sections, which is normally used when dealing
modifying the internal members of an existing truss. Both of these
methods are based on the assumption that when a structure is in
equilibrium, all pieces of the structure are also in equilibrium.