MECH2413
Engineering Mechanics
Chapter 03: Stress & strain
Content
In previous chapter, the notion of stress in a bar has
been introduced. We will now generalize the concept
of stress and strain, to make it applicable to arbitrary
structures. It includes

21
Chapter 2. Kinetics
2.1 Rectilinear Motion (Newtons law)
Newtons second law states that the total force on a particle is equal to the rate of change
of its linear momentum, which is the product of its mass and velocity:
d
F
mV ,
dt
dV
if m is constan

Force Resultantes:
Beams under
concentrated loading
Beams under concentrated Loads
General procedures for statically determinate
problem:
1) Equilibrium of whole beam:
a) Moment about support
b) force
2) Section method
3) Draw force/moment diagram
Force

MECH2413
Engineering Mechanics
Teachers and TAs
Statics:
Dr. Chen, Yue (yuechen@hku.hk)
Miss Li, Shasha (shashali@connect.hku.hk)
Dynamics
Dr. Kwok, Ka-Wai (kwokkw@hku.hk)
Mr. Guo, Ziyan (guoziyan@connect.hku.hk)
Materials Modeling Introduction to my re

MECH2413
Engineering Mechanics
Chapter 07: Torsion
Content
In previous chapters, we calculate the deformations and
stresses that are caused by the loading.
In this chapter, we investigate shafts that are twisted by
external torques. The basic equations

Mohrs Circle
Mohrs Circle
Must draw this to show +ve direction. Here,
Anti-clockwise direction is referred as +ve
(Shear
Stress)
(x,xy)
2
S
P(y,xy)
S
(Normal
Stress)
Mohrs Circle
Radius & inclined angle
2 2
= (
) + =
2
2
2 =
2 =
2
2 =
Hence, the

MECH2413
Engineering Mechanics
Chapter 06: Deflection of Beams
1
Content
In this chapter, we will discuss the geometric result of a
beam being stressed: Deflection.
First of all, a summary of important equations are given
for the ordinary bending theory

Chapter 5. REENTRY DYNAMICS
5.1 Motion with Velocity Dependent Forces (VDF)
Spacecraft and satellite have tight mass budget. By the time they
need to land, very little fuel is left for active manouvre (such as
backward jet propulsion as shown at right). A

g p _ . _ ,80
Chapter 4.- ROCKETENGINEERING
4.1 Introduction, History 2-1970
cfw_2' I '5
Gunpowder was accidentally invented by Taoist alchemy (WE) hence the name X
(medicine with re). It was gradually used in weapon (solid fuel rocket) from about Han
d

67
Chapter 4. ROCKET ENGINEERING
4.1 Introduction, History -1970
Gunpowder was accidentally invented by Taoist alchemy () hence the name
(medicine with fire). It was gradually used in weapon (solid fuel rocket) from about Han
dynasty, such as the battle

MECH2413
Engineering Mechanics
Chapter 04: Thin-Walled Pressure Vessel
Introduction
Introduction
Both cylindrical and spherical thin-walled pressure
vessels are very widely used in the industry, e.g. gas
tank, submarine, heat exchanger.
Introduction
E.g

45
Chapter 3. ORBITAL MECHANICS
3.1 Introduction, Keplers Laws
Using his teachers (Tycho Brahe, Danish, 1546-1601) astronomical data,
Johannes Kepler (German mathematician 1571-1630, Ming Dynasty in
China) observed the following empirical laws about the p

80
Chapter 4. ROCKET ENGINEERING
4.1 Introduction, History -1970
Gunpowder was accidentally invented by Taoist alchemy () hence the name
(medicine with fire). It was gradually used in weapon (solid fuel rocket) from about Han
dynasty, such as the battle

Integral: Example #1
With q = q0 = constant, we have
These two equations can be applied to different
configurations of same type of loading.
(a)
(b)
(c)
Integral: Example #1
The boundary conditions
Hence,
By solving the above equations, we have
(a)
(

MECH2413
Engineering Mechanics
Chapter 02: Force & moment resultantes
Content
Beams are among the most important elements in
structural engineering. In this chapter, the resultant
of external load to a beam is studied, including
1) Force & moment resulta

MECH2413
Engineering Mechanics
Chapter 05: Bending of Beams
Content
In previous chapter, we have studied the stress
distribution along the axis of a beam.
In this chapter, we will discuss the normal stress
distribution across the section of a beam inclu