Designing, Analyzing and Simulating Mechanism Using FEA
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TWO DIRECTION MECHANISM Group (1) Under supervision Professor Mostafa Helaly M.Sc Mostafa Yakout PE - 253 Theory of Machines Production Engineering Department Designing, Analyzing (motion and force) and Simulating using FEA 21 – 05 – 2014 1
Designing, Analyzing and Simulating Mechanism Using FEA
This Presentation was made by Mohamed Mostafa Ahmed Adam Beshoy Rafat Eman Abd-Elfatah Mahmoud Khairy Mohamed Ibrahim Khloud Amer Toka Mohamed Ahmed Wael Mohamed Ismail CAD Drawing was made by Mohamed Ibrahim Introduction Selection of Mechanism Two-Direction Mechanism is our selected mechanism. It is quite distinctive, as it enables a rider to ride a bicycle backward but the bicycle goes forward. That attracted our team to work on this mechanism. Great experience we gained in the fields of Mechanical Design, Finite Element Analysis, Ergonomics and other fields is involved in this report. Ergonomics Considerations A rider uses many muscles to ride a bicycle (muscles of arms, shoulders, back and legs). TWO DIRECTION MECHANISM comfort rider’s legs as it allows him/her to ride a bicycle forward or backward to go forward with the bicycle. When a rider uses this mechanism in the bicycle he/she will relief the muscles of leg as muscles will exert reversing effort. Environmental Considerations Riding bicycles uses TWO DIRECTION MECHANISM can effect transportation, because people will be able to go with bicycles a longer distance in a shorter time. Imagine the large number of vehicles that will leave roads to stay in garages and the enormous amount of gasoline people will save. Material Selection The recommended material for gears is Aluminum Alloy 7075. It has the following advantages: • High Stiffness to Density Ratio • High Strength to Weight Ratio • High Corrosion Resistance Analysis Process We have used FEA (Finite Element Analysis Method) (Finite Element Analysis) A mathematical technique for analyzing stress, which breaks down a physical structure into substructures called "finite elements." The finite elements and their interrelationships are converted into equation form and solved mathematically. The aim of the analysis study using FEA was to get the results for the following parameters 1.Yield Criteria Von Mises Stress 2.Equivalent Elastic Strain 3.Total Deformation
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1.Group (1) Under supervision Professor Mostafa Helaly M.Sc
Mostafa Yakout PE - 253 Theory of Machines Production Engineering
Department Designing, Analyzing (motion and force) and Simulating
using FEA 21 05 2014 1
2. Group(1) 2 3. Group(1) In This short presentation we will
discuss the follwoing : Why choosing Two-Direction Mechanisum
Introduction the Mechanisum The Design Process The Analysis Process
Conclusion 3 4. Group(1) According to the latest studies by The
World Economic Forum That top ten problems facing the world in the
future are caused by 2 main problems And they are 4 Source : Global
Risks 2014 report. USA Today 5. Group(1) 5 Source
:CommuterBikeCenter.com 6. Group(1) 6 Knee Pain (from 40% to 60% )
Muscle Contraction (from 55% to 78%) Stress on anterior knee from
pedaling (80%) Leg inflexibility Source : Peak Performance Sport UK
7. Group(1) 7 8. Group(1) The Two Direction Mechanism consists of
four gears. Three of them are almost the same size and the forth is
relatively small. The fourth gear is held on a curved slider 8 9.
Group(1) Motion Type: Rotational for the main three gears. General
motion (rotational and translation) for the small gear Material
used: Aluminum Alloy 7075-S Function: The main function of the Two
Direction Mechanism is to constrain the direction of output motion
to one direction regardless the direction of the input rotational
motion. 9 10. Group(1) First we will use Aluminum Alloy 7075 for
gear manufacturing Pedal is made of aluminum and covered by Rubber
or Plastic that is rigged Because the stresses on pedal is
compressive fatigue stress so we need a material of high endurance
limit and to make the bicycle more relax for the rider means has
high strength to weight ratio and these properties found in
Aluminum alloys 10 11. Group(1) 11 12. Group(1) 12 13. Group(1) 13
14. Group(1) 14 15. Group(1) 15 16. Group(1) 16 17. Group(1) 17 18.
Group(1) 18 19. Group(1) We have input an average human pedaling
speed which is 90 rpm So the output result in mechanism was about
200 rpm. 19 20. Group(1) The output average acceleration was about
1300 DEG/ 20 21. Group(1) We have used FEA (Finite Element Analysis
Method ) (Finite Element Analysis) A mathematical technique for
analyzing stress, which breaks down a physical structure into
substructures called "finite elements." The finite elements and
their interrelationships are converted into equation form and
solved mathematically. Graphics-based FEA software can display the
model on screen as it is being built and, after analysis, display
the object's reactions under load conditions. Models created in
popular CAD packages can often be accepted by FEA software (Ansys
Workbench ) . 21 22. Group(1) 22 We used transit structure to
analyze the design 23. Group(1) 23 (Von-Misses Yield Criteria ) 24.
Group(1) 24 (Equlavalent Elastic Strain ) 25. Group(1) 25 (Total
Deformation ) 26. Group(1) 26 We have send our design to a world
wide clinic that is specialized in cycling injuries (Chester Knee
Clinc) UK They were delighted by the design and will be in contact
with us for further improvement in the design process of the
product in terms of manufacturing and Design . Mr Vladimir Bobic
Consultant Orthopaedic Knee Surgeon (Im really happy to find this
type of thinking and enthusiasm in the youth of your country this
is way more than college mini project .. You are more than a
project good luck) 27. Group(1) 27
