1. Project/Skill Set Samples Portfolio
The following pages are meant to demonstrate my skill set in design and
engineering. Thank you in advance for your time and consideration.
Sincerely, Huizhe (Lucy) Zhao
2. Engineering Design Project: Tire Stacking
Robot
GOAL: Stack tires on a series of poles lined up within a 10
cm horizontal range along a straight line. The poles
would have either zero, one, or two tires when first
placed, and the robot shall stack tires so that each pole
results with exactly two tires. The robot is to travel over
a distance of 1.5 m, with 10 poles placed along the path.
3.Tire Dispensing System: rack and pinion, 12V gearbox DC motor
2. Tire Conveying System:
12V gearbox DC motor,
threaded rod, bolt (press
fitted into the wood piece)
1. Tire Shooting System: 12V gearbox DC
motor, steel rod
Tire
Pole SIZE: 48 cm × 30 cm × 50 cm
WEIGHT: 3.6 kg
VELOCITY: 0.4 m/s
ACCELERATION: 2.38 m/s2
4. Wing Rigger Failure Analysis ReportExecutive Summary: In this failure analysis, the fracture of an aluminum wing rigger from a
rowing scull was examined. The rigger fractured along almost its entire width. This study
analyzed the failure mechanism of the component, and determined that the part failed due to
yielding near a corrosion site.
Keywords: Fracture — Aluminum — Failure Analysis (FMEA)— Fault Tree
Figure 1: Wing rigger in service
1. Material: 6005A-T61 extruded
aluminum with surface left as mill finish
Table 1: Material properties
2. Analysis of Stress and Strain on Component
2.1. Cyclic Loading
- Rower takes 300,000 strokes per year
- During each stroke, the rower applies a
maximum value of 400 N where the oar
connects with the rigger (Smith, 2002)
- Applied force to the rigger is constant every
stroke (Kleshnev, 2015)
2.2. Collision Incident
- The rigger broke during collision incident
involving 2 athletes
Figure 2: Diagram of impact event
- Assume inelastic collision and using beam
theory:
𝐹 = 𝑚
𝑑𝑉
𝑑𝑡
𝑀 = 𝑟 × 𝐹
σ =
𝑀𝑐
𝐼
𝐼 =
1
12
𝑏ℎ3
- Obtain maximum stress at the fracture
location on rigger= 236.06 MPa
2.3. Characterizing the Failure
- Semi-ductile fracture surface (cup and cone
fracture surfaces; small facture surface
perpendicular to the tensile stress between
two shear lips)
Figure 3: Shear lips
- Observed corrosion pits
3. Conclusion
-Corrosion defect coupled with local stresses during
collision above ultimate tensile stress of material led to
failure
Figure 5: Stress experienced during impact
Figure 4: Pitting corrosions
Figure 6: Highest stress experienced at corrosion
pit
Figure 7: Fault Tree
2.4. Finite Element Analysis
Kleshnev, V. (2005). Comparison of on-water rowing withitssimulationonconcept2androwperfectmachines. International Society of biomechanics in Sports, Beijing, China
Smith, R. and Loschner, C. (2002) Biomechanics feedback for rowing, Journal of Sports Sciences, 20:10, 783791
6. Engineering Consulting Project: Cost-Saving Opportunities for Dajcor Aluminum Ltd.
GOAL: Evaluate a set of potential facility upgrades and choose the solution that provides the highest Net Present Value (NPV) for Dajcor (small local business)
Solution 1: Install Ecomax 8 CHP Unit
Engine Model Result Ecomax 8
Power Rating 848 kW
Thermal Rating 1,089 kW
Fuel Consumption 2,216 kW
Electrical Efficiency 38.3%
Thermal Efficiency 49.1%
System Efficiency 87.4%
Capital Cost $1,991,850
-CHP Sizer tool interface see below:
Sizer tool determines the optimal CHP unit
specifications for a given set of utility usage and
pricing information.
Solution 2: Install Belt Dryer System for Filter Cake
Drying
-Economic analysis results in transportation cost savings of
$5700/month, maintenance cost of 1000$/yr, electrical load of
36,000 KWh/yr, heat load of 4420 GJ/yr, capital cost of $158,000
Solution 3: Install Anodizing Tank Mechanical Covers
-Cost saving inputs and outputs see below:
4. Decision Making Model
-Compares feasibility of the aforementioned cost-saving
opportunities based on NPV, EAA (equivalent annual annuity) and
payback period. Model interface see below:
5. Ranked Solutions
-Ecomax 8 CHP unit is the top ranked solution. See below:
