Page Comparison

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• 4130 Chromoly Steel

  • Excellent strength-to-weight ratio

  • High tensile strength, ductility, and toughness

  • Lightweight in tubing form

    • In non-tubing form:

      • Modulus of Elasticity - 205 GPa

      • Ultimate Tensile Strength - 670 MPa

      • Tensile Yield Strength - 435 MPa

      • Rockwell B Hardness - 92

      • Elongation at Break - 25.5%

• AX-5201XL Carbon Fiber

  • High stiffness, tensile strength, chemical resistance, and temperature tolerance

  • Low thermal expansion and weight-to-strength ratio

  • Excellent in tension

    • In general:

      • Modulus of Elasticity - ~230 GPa

      • Ultimate Tensile Strength - ~3.5 GPa

      • Tensile Yield Strength - ~2.1 GPa

  • Horrible in compression, but epoxy’s advantage in compression usually cancels that out when they form a composite

    • However, since we are by no means experts who manufacture our parts in a professional setting with quality equipment, I think we should lower our expectations when it comes to the material quality of not only our composites made with the Prepreg method, but the epoxy component specifically. I mean to say that the compressive counteraction that we look for in the carbon fibre composite, due to the epoxy’s presence, may not be expressed as strongly as we need it to be. Although, the NOMEX component might fix this issue.

• NOMEX

  • High compressive strength, shear strength, materials compatibility, and fatigue strength

  • Low volume density and weight-to-strength ratio

  • High structural integrity

    • In general:

      • Ultimate Compressive Strength - ~2 MPa

      • Most other qualities change drastically based on stress direction

• LOCTITE EA E-120HP

  • Superior thermal shock resistance

  • Excellent mechanical and electrical properties

    • Specifically peel and impact forces

    • Suitable for low stress [I wonder if that will be a problem.]

  • Withstands exposure to a wide variety of solvents and chemicals

  • Bonds dissimilar materials including aluminum, steel, and other metals, as well as a variety of plastics and ceramics

    • No mention of metal to organic compounds however

      • From Technical Data Sheet (TDS):

        • Modulus of Elasticity (general epoxy resins) - ~4.5 GPa

        • Shear Modulus (general epoxy resins) - ~2.1 GPa

        • Average Tensile Strength - 41 GPa

        • Lap Shear Strength (Stainless Steel) - 23 GPa

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1. Adhesive Yield Strength

   1. Determine how much the adhesive can withstand

   2. Tensile and shear stress must be tested

   3. Yield is different for application, so maybe just figure out when it crosses a certain elongation?

   4. Then find amount of force required

2. General Weight

   1. Determine safety factor and actual strain elongation

   2. Needed: surface area, bottom panel mass

3. Quality

   1. Determine air bubbles?

   2. Determine shrinkage?

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1. Constant elastic and shear modulus, max elongation of 3 mm, max strain is then 5 Pa (5*10^-9 GPa), constant SA (in mm^2)assumed height is 2 mm, max horizontal displacement of 1 mm, constant SA (in mm^2)

   1. σ=Eε, σ=F/A, and ε=∆h/h

   2. τ=Gγ, τ=F/A, and γ=∆x/h

   3. Find F for both.

2. Constant SA (in mm^2), gravity is rounded to 9.8 m/s^2, mass unknown, constant elastic modulus, assumed height is 2 mm, average tensile strength of epoxy given

   1. F=mg, σ=F/A, σ=Eε, and ε=∆h/h

   2. SF=σ_avg/σ

3. N/A

• SW

1. N/A

2. FEA of weight

3. N/A

• Physical

1. Test amount of force required for adhesive to yield directly

2. Not needed.

3. Physical examinations

Expectations

• MODS/Pre-calculations

1. I expect it to be a very high force needed.

2. I expect the change in height to be extremely minimal

3. N/A

• SW

• Physical

Results

• MODS/Pre-Calculations

Mostly done, I just need the mass of the bottom panel.

• SW

• Physical

Analysis