代写MMAN4410 Major Report Proposal: bicycle frame代做Statistics统计

MMAN4410 Major Report Proposal: bicycle frame

Aim of the project

Develop a city bicycle frame. that can withstand daily usage in normal road conditions and reach a service life of 10 years, mandatory maintenance considered.

The frame. would be designed as two triangles connected by the main beam, which links to the seats and paddle, shown in the photo below. Being one of the most commonly used geometry design, this allows distribution of force throughout the beam to avoid centralizing stress at particular positions.

 

Specific application characteristics

Four types of materials are considered, and major factors listed in order, having 1 being the best performance and 4 being the worst in comparison.

	Carbon Fiber	Aluminium	Titanium	Steel
Weight	1	3	2	4
Cost	3	1	4	2
Durability	3	2	1	1
Strength	1	3	2	4

Hence, as city riders experience high frequency usage while low performance requirement, and use it as a daily transportation method, cost and durability would be the priority, followed by weight and strength. Therefore, Aluminium is chosen to be the material of city bike frame.

A type of aluminium alloy commonly used for bikes named Aluminum 6061-T6 will be considered in the design, specs listed below.

Properties	Aluminium 6061-T6	Unit
Density	2.7	g/cm^3
Poisson ratio	0.33
Yield Strength	276	MPa
Tensile strength	310	MPa
Fatigue strength	96.5	MPa

The maximum weight a city bike can handle in the design is set at 100kg, being the average capacity of a city bike. If higher capacity is required, the beams can be strengthened accordingly.

The frame. will be composed of thick hollow circular beams wielded together

Specific assumption:

In the simulation, it is assumed that the rider is in seating position, with 50% of weight at the seat, 5% at the handle, and the rest at the paddle. They will be assumed to apply downwards for simplicity of the analysis. All connections are welded properly, and standard gravity of 9.861m/s^2 is consistent.

Key criteria for evaluating the outcome:

-     Fatigue life of the structure that deforms overtime

-     Nominal and maximum stress the frame. can reach to verify whether it has the capability to reach the standard

-     Load multiplier from eigenvalue buckling to identify maximum load it can handle

Outline of FEA type to use, at least two

Fatigue analysis, static structural and eigenvalue buckling.

Validation and verification approach:

The final value of eigenvalue buckling will be compared with the aim of 100kg to see whether it meets the standard; life minimum of cycles will be compared with service life of 10 years to verify whether the service life will be reached; identifying concentrated stress location and making sure it does not reach beyond material yield strength.