Feasibility AnalysisP14415

Thermoforming Quote- CJK

DIY Vacuum Forming

• Use kitchen oven to heat plastic

• Use shop-vac with vacuum box shown

• Build vacuum box for under $100

• Shop-vac costs $69-$299

• External Heat source possibility

• Quote for New and Used Machines

Purchasing Vacuum Forming Mach.

• Cost: $12,900

• http://www.belovac.com/

ABS vs. PolycarbonatePolycarbonatePros:•Outstanding toughness•Good optical clarity•Strong and stiff•Easy to fabricate•Easy to solvent bond••Cons:•Expensive compared to ABS•Good resistance to UV with stabilizers•Thermoforms well after drying

ABSPros:•Outstanding impact resistance•Good machinability•Easy to thermoform•Easy to bond with adhesives•Strong and stiff•Low cost•Cons:•Poor UV resistance•Becomes brittle with UV stabilizers•

Material Eliminations:

Acrylic: Brittle

Polyethylene (HDPE/LDPE): Poor material strength properties compared to ABS

Polycarbonate: Expensive relative to ABS (2x the cost for most sheets)

Curbellplastics.com

Material Research References:http://www.morganclaypool.com/doi/pdf/10.2200/S00184ED1V01Y200904MRE001

http://plastruct.com/Pages/Properties.html

http://www.toolcraft.co.uk/vacuum-forming-material-specs-abs-hips-hdpe-petg-pp-pvc.htm

http://www.machinist-materials.com/comparison_table_for_plastics.htm

http://www.curbellplastics.com/technical-resources/plastics-properties-table.asp?cols=&compare=1,2,6,8,16,17,21,23,24&direction=desc

Design 1 Models

Design 1 Models

Design 1 Models

Design 1 Models

Ansys Analysis - Design 1 Summary

• Max Stress: ~1.5x Ultimate Strength Values

• Too high of stress values for fairly conservative model of worst case

• Design is insufficient as is to move forward with

• Needs redesign with added strength from additional supports: metal

Ansys Analysis - Modeling Summary

• Worst Case and Normal Usage

• Multiple Discussions with Dr. Boedo and Dr. Debartolo

• Worst Case: Load (270lbs) around hole

• Normal Usage: Load (270lbs) across two locations at normal stance width

• Only base modeled, without material thinning

• Iterative solution modeling

Ansys Analysis - Results Summary

Design 1 - Stresses: Normal Loading

Circles denote peak stress locations.

Design 1 - Deflection: Normal Loading

Design 1 - Meshing: Normal Loading

Design 1 - Stresses: Normal Loading

Circles denote peak stress locations.

Design 1 - Deflection: Normal Loading

Design 1 - Meshing: Normal Loading

Design 1 Feedback

Ansys Analysis - Conclusions

• Stresses too high for a fairly conservative model

• Redesign required with additional supports, such as rebar

• Debartolo believed analysis and conclusions seemed valid

Design 2 - Analysis

Assumptions

• Rigid supports for deflection between ribs

• Cantilevered rib bending

Design 2 - Analysis

Deflection between rigid supports

Design 2 - Analysis

Deflection of Ribs

Design 2 - Analysis

Design 2 - Feedback

Dr. Debartolo• Assumptions inappropriate

• Need to assume ribs pinned, not cantilevered

• Need to assume deflection between ribs is cantilevered

• Distributed load will reduce deflection between ribs

Design 2 - Moving Forward

• Redo calculations with new boundary condition assumptions

• Possibly change material based on new analysis

Shipping Costs- Miami To Haiti (Preliminary Analysis)

-Analysis of per unit cost if container is filled to capacity

-Assumptions:

- One day storage before loading and after unloading (2 days total)

- Weight does not affect cost

- Cost per part is determined by volume

Shipping Costs- Data

Shipping Costs- Calculations

New Risks

Risk Chart Entry: