King Fahd University of Petroleum & Minerals
College of Engineering Sciences
Mechanical Engineering Department
ME 307: Machine Design I
HW # 1
Chapter 3: Load and Stress Analysis
First Semester 2013-2014(131)
Due Date: Tuesday 24/09/2013
Problem # 1 For t
LECTURE # 12
Lecture 12
Deflection due to Bending (Recap)
It is easier to find equations for V and M (Shear Force and Bending Moment
Distribution) than y (Deflection Distribution).
ME-307 Lecture
Dr. Sulaiman Pashah
3
Deflection due to Bending (Continued)
LECTURE # 11
Lecture 11
Deflection
The size of a load-bearing component is often determined on deflections, rather than
.limits on stress
Example: Gears on Shaft
In a transmission, the gears must be
. supported by a rigid shaft
,If the shaft bends too muc
LECTURE # 7
Lecture 07
Bending Stresses (Normal)
A beam under pure bending
No Shear Force
Assumption of pure bending : To eliminate the complicating effects of shear force
during derivation.
Generally beams have both shear forces and bending moments.
For
LECTURE # 3
Lecture 03
Recap Lecture # 2
1.
2.
3.
The objective of design problem is to verify whether or not the machine element is
safe under applied load.
The applied load can be in following forms
Force, Moment and Torque
If failure occurs, it would b
King Fahd University of Petroleum &
Minerals
College of Engineering Sciences
Mechanical Engineering Department
ME 210 Mechanical Engineering
Drawing & Graphics
Module 4: To Construct Housing
Body and Add Multiple Features
Prepared by:
Muhammad Younas and
King Fahd University of Petroleum &
Minerals
College of Engineering Sciences
Mechanical Engineering Department
ME 210 Mechanical Engineering
Drawing & Graphics
Module 8: Assembling Housing
Parts
Prepared by:
Muhammad Younas and John OBrien
July August, 20
LECTURE # 15
Lecture 15
Strength and Failure
Strength is a property of a mechanical element to provide intended function
without failure
It results from
Material properties
Material treatment
Processing
Loading
Failure means unfit to perform required func
LECTURE # 15
Lecture 15
Strength and Failure
Strength is a property of a mechanical element to provide intended function
without failure
It results from
Material properties
Material treatment
Processing
Loading
Failure means unfit to perform required func
23
CHAPTER 6
FAILURE ANALYSIS VARIABLE LOADING
We analyzed the machine elements for static/steady loading in Chapter 5. Often the
machine elements are subjected to variable or changing loads in time. The failure
analysis of mechanical systems under variab
20
CHAPTER 5
FAILURE THEORIES STATIC LOADING
The failure theories in this chapter explain mechanisms of failure for the machine
elements subjected to loads and stresses that do not change with time. We now know
how to calculate stresses due to tension, be
King Fahd University of Petroleum & Minerals
College of Engineering Sciences
Mechanical Engineering Department
ME 307: Machine Design I
HW # 3
Chapter 5: Failure Resulting From Static Loading
First Semester 2013-2014(131)
Due Date: Sunday, 03/11/2013
P
King F
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Colleg of En
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Mechani
M
ical Eng
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nt
ME 307 M
Machine Design I
Homew
work 4
First Semester 2013-2014 (131)
)
Chapter 6: Fatigue F
:
Failure Resu
ulting fr
King Fahd University of Petroleum & Minerals
College of Engineering Sciences
Mechanical Engineering Department
ME 307: Machine Design I
HW # 2
Chapter 4: Deflection and Stiffness
First Semester 2013-2014(131)
Due Date: Sunday 06/10/2013
Proble m # 1:
Usin
LECTURE # 26
Lecture 26
Estimating Stress Concentrations (Shaft Design)
Geometric discontinuities are required due to functional requirements:
Shoulders (with fillet and grooves) for bearings
Keys and Pins for Gears and Pulleys
Stress concentration factor
LECTURE # 27
Lecture 27
Deflection Considerations (Shaft Design)
Deflection of the shaft, both linear and angular, should be checked at gears
and bearings.
Values should not cross the allowable limits to avoid misalignment
due to deflection.
Deflections d
LECTURE # 23
Lecture 23
Rotating Beam Specimen
Fluctuating stresses have sinusoidal pattern due to the rotating motion.
Stress
Stress State for
One Revolution
Time
Consider a point on beam cross-section
initially at Neutral Axis (Point A)
w
D
C
A
A
B
One
LECTURE # 22
Lecture 22
STRESS CONCENTRATION
Tension/Compression, F A
F S
Shear
Assumption:
Bending My I No geometric irregularities occur in
the member
Torsion Tr J
Machine elements must have geometric changes in the cross sections for their
functionali
LECTURE # 21
Lecture 21
Fatigue Strength by Rotating Beam Specimen (Recap)
Stress Reversal Tests
To obtain Se and (Sf , N) data
The machine subjects the
specimen to pure bending
Completely reversed stress due to
rotation
The specimen is carefully
machined
LECTURE # 20
Lecture 20
Fatigue Strength (Recap)
Static Failure
Strength is material property (Sy or Sut)
Fatigue Failure
Applied load Fluctuates with time (Cyclic load)
Example: Rotating Shaft under bending load (completely reversed stress)
Failure can o
LECTURE # 19
Lecture 19
Introduction to Fatigue in Metals
Static Loading
Load is applied gradually
Sufficient time for the strain to fully develop.
The specimen is tested to destruction,
So the stresses are applied only once.
Variable Loading
Stresses var
LECTURE # 13
Lecture 13
Strain Energy
A spring is a flexible element that
deforms when acted upon by a
force.
l
The External Work (W) on spring in
deforming it is transformed into
F
l+
Strain or Potential Energy (U)
2
1 2 F
U k
Fd
2
2k
0
F
U
Strain Energ
King Fahd University of Petroleum &
Minerals
College of Engineering Sciences
Mechanical Engineering Department
ME 210 Mechanical Engineering
Drawing & Graphics
Module 5: To Create the 2-D
Drawing from a 3-D Model
Prepared by:
Muhammad Younas and John OBri