Department of Civil Engineering
Moment of inertia (Second Moment) for an area
Geometric property that is calculated about an axis, and for
the x and y axes
I x y 2 dA
0
2
I y x dA
mathematical expression
No physical meaning
always positive
Units =

Civil Engineering Mechanics
CVG2149
Review:
Forces in Plane
Forces in Space
Forces and Vectors
Replacing multiple forces acting on a particle with a single equivalent or
resultant force
Relations between forces acting on a particle that is in a state of e

Department of Civil Engineering
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, Newtons 3rd Law states that the
forces of acti

Department of Civil Engineering
Definition
Structure composed of slender members joined together at
their end points
2
Definition
One of the major types of engineering structures (bridges and
roofs).
3
Types of Trusses
4
Simple truss
A truss compos

Department of Civil Engineering
2
Various Types of Beam Loading and Support
Beam - structural member (long and prismatic)
designed to support loads applied at various
points along its length.
Beam can be subjected to concentrated loads or
distributed lo

Department of Civil Engineering
Mechanics: The study of how bodies
react to the forces acting on them.
Statics: The study of
bodies in equilibrium.
Dynamics:
1. Kinematics concerned with
the geometric aspects of motion
2. Kinetics - concerned with
the for

Department of Civil Engineering
Kinematics of rigid bodies: relations between
time and the positions, velocities, and
accelerations of the particles forming a rigid
body.
Classification of rigid body motions:
- translation:
rectilinear translation
cur

Department of Civil Engineering
The boat and trailer undergo
rectilinear motion.
How many equations of motion
do we need to solve this problem?
What are they?
2
The pendulum of the Charpy impact machine
rotates about fixed axis at A.
3
Consider a rigid bo

CVG 2149
Civil Engineering Mechanics
Dynamic forces and structural models
The subject presented herein deals with the response of structures subjected to dynamic forces
or loads, whose magnitude varies with time. Generally, most of the forces applied to a

Formula Sheet
Cables:
tan
T T02 W 2
tan
T T02 w2 x 2
y
W
T0
wx
T0
wx 2
2T0
Motion:
Linear:
Curvilinear:
dv
v2
a et en
dt
dv
at
dt
v r er r e
, an
a r r 2 er r 2r e
Kinetics of Particles:
F ma
F t mat
dv
Ft m
dt
F n ma n
Fn m
v2
Fr ma r mr r 2
F m

Department of Civil Engineering
Centroid of an area
Point that defines the geometric center for the area
y
h/2
x
c
h/2
b/2
b/2
2
Centroid of an area
For the area of an arbitrary shape
xdA
x
dA
ydA
y
dA
Moment of the area element
dA about the y and x