Lecture 3: Superposition, Stress
concentrations
Learning Outcomes
Compute stresses resulting from combination of loads
Identify and compute stress concentrations
Locate and compute maximum stresses in simple systems
1
Lecture 2: Summary
Bending stresse
Lecture 8: Shafts I
Learning Outcomes
Design a shaft:
Locate shaft elements
Prevent failure
1
Snowmobile track drive shaft
chain sprocket
track sprockets
What are the functions of
this shaft?
2
Snowmobile track drive shaft
3
Snowmobile track drive shaft
MECH 393
Tutorial 2
September 18, 2015
Problem 1
This problem illustrates that the factor of safety for a machine element depends on the particular point
selected for the analysis. Here you are to compute factors of safety, based upon the distortion-energ
MECH 393
Tutorial 1
September 11, 2015
Problem 1
A gear reduction unit uses the countershaft shown in the figure. Gear A receives power from another gear
with the transmitted force FA applied at a 20 pressure angle as shown. The power is transmitted throu
Lecture 7: Fatigue Failure III
Learning Outcomes
Predict fatigue failure under multiaxial loading
Predict fatigue failure under varying fluctuating loads
1
Combinations of Loading Modes
When more than one type of loading (bending, axial, torsion) exists
Lecture 6: Fatigue Failure II
Learning Outcomes
Predict fatigue failure in the presence of stress
concentrations
Incorporate the effect of mean stress for non-fully reversed
cycles
1
Stress Concentration and Notch
Sensitivity
For dynamic loading, stress
Lecture 5: Fatigue Failure I
Learning Outcomes
Interpret S-N curve, fatigue strength, endurance limit
Predict fatigue strength, endurance limit for steel
Construct full S-N curves for steel
Predict fatigue strength for an actual machine part
1
de Havi
Lecture 9: Shafts II
Learning Outcomes
Design a shaft:
Minimize deflections
Design mounting elements
1
4) Deflection of shafts
Excessive deflection/angular deflection is detrimental
to shaft elements (gears, bearings)
(Diameter may have
to be increased to
LIT Fa unhquanmy lined. indium dimension: using fame is
lprimuy dim nudgivc typical Slnnd Euglimnits:
a. Power
b. Prawn:
c. Modulus of clauicity
d. Angular velocity
6. Elm
f. Momentum
3. Slur sues:
h. Specic hm
i. 'numal expansion coefcient
3'. Angula- mm
USEFUL EQUATIONS
1. p2
p1 =
(z2
2. FR = hc A,
z1 )
yR =
Ixc
yc A
+ yc
3. p + 1 V 2 + gz = constant
2
4. F = V
5. =
du
dr
6. m = V A
7. Material Derivative:
Du
Dt
=
@u
@t
~
+ V r u
8. Reynolds Transport Theorem:
R
R
DBsys
@
~n
= @ t cv b dV + cs bV ~ dA
D
Handout A1 (MECH 331)
MECH 331 Fluids I
Fall 2016
Instructor:
Lectures:
Tutorial:
Office hours:
Textbook:
T.A.:
Grader:
Prof. Tim Lee, MC211, tim.lee@mcgill.ca
M W 2:35 3:55 ; MD280
Tues 2:35 3:25 ; MD280 (might be used for lecturing occasionally)
M W 12:
A2 handout (MECH 331)
Chapters 1 and 2: Introduction and Fundamental Concepts
1. Continuum fluid mechanics (CFM)
2. The Newtons law of viscosity
3. Stress field
4. Dimensions and units
5. Significance of Reynolds number ( Re =
U C
)
5a. Definition
5b. Sig
A3 Handout (F2016)
Chapter 4: Basic equations in integral form for a control volume
Part A: for Inertial control volume
1. Basic laws for a system (on a rate basis)
2. Reynolds Transport Theorem (RTT)
Note:
Control volume (CV) An arbitrary volume in space
Designing the
@(MM Human Power
Creative. engineering credited as
AeroVelo achieves "impossible"
human-powered helo flight
I'll-diam Warwick Waillngton
t-took 33 years, but perhaps the nal great feat of human
I endearer' in aviation has been scoomp'lishe
F
lam shown. dc-
J;
T
igncd to reduce pressure pulsa-
ins
machine tool hydraulic system. For the
the rate at which the accumulator gains or loses hydraulic oil.
inn
T Ahydraulic accwnuiararis
- 5.75 3pm >
H.357 Width.
w=1.5m
1-?-
-o.2i mmlsj d
L
Lecture 4: Failure from static loading
Learning Outcomes
Select an appropriate failure criterion
Predict where and at what load failure will occur
Compute safety factors
1
Definition of failure
Any of these is considered failure:
The part has separated