156B Week 7

Status:

The team has continued to run new analytical design tests to ensure stability and that the critical joints of the spar are structurally sound. CAD models and FEAs have been improved and now more accurately represent the spar mooring. With the help of Professor Tustaniwskyj, beam analysis is being explored to calculate forces and moments at the spar joints to understand the stresses so that we may conduct hardware testing on the critical physical connections. A scaled down model of the 10m spar has been started and will be used to represent the preliminary design. Priority at the moment is acquiring all necessary materials and parts, as this is currently the aspect that can jeopardize the team’s schedule. However, the team is still on track to have the physical full-scale project constructed by the end of week 8.

Accomplishments from Previous Week

• Continued work on Final Report.

• Scale model prototype production was started.

• Suppliers were contacted to find the necessary bell-end 10ft long 6in ID PVC pipes necessary for our design

• Tolerances for machining were determined for the spar base

Goals for Next Week (list names after each item). Use specific and measurable objectives.

• Make corrections to Final Report and update to make a better draft (Team)

• Start on the preliminary Design presentation (Team)

• Continue working on the prototype (Erik Zamarripa & Ayesha Riaz & Eliran Lenard)

• Create CAM file of the spar base for machining (Horim, Erik)

• Review flow conditions and calculations and confirm with Prof. Pawlak to ensure correct values are used in final analysis (Horim)

• Acquire tools necessary for creating spar sections (Erik)

• Finish probe holder design and 3D print support fixture (Ayesha)

• Perform updated FEAs with all final component properties and imposed forces (Eliran Quentin)

Sponsor Comments from Last Meeting (Zoom meeting 2/9/21)

• Discussed modifying the base/ the swivel mechanism

• FEA on the base especially at the joint

• Emphasized the need to determine the forces acting on the spar and finding the reaction of the structure at the base, joints, and guywire connections

• Discussed the forces at the joint where the guywires will be attached

• Discussed how the prototype will be manufactured

• Showed the NAPCO pipes and fitting to reduce the non-linearity analysis of the spar

Instructor Comments from Last Meeting (Zoom meeting 2/9/21 and 2/12/21)

• Discussed the spar joint modeling problem and offered guidance in the use of beam analysis to calculate stresses and moments on the spar.

• Informed that failure of PVC occurs with high tensile stress which is typically the first principal stress and that there is no real value in our application in showing all three principal stresses -> report and presentations will be made more concise

• Final report Feedback

  • Think the audience as technical but familiar with your project

  • Add some figures/numbers/captions

  • Use pictures describe and relate with your project

  • Need to write in 3rd person

  • Write more specific descriptions of the project and components

  • Find details in your report on what the loading is, dimension where the guy wires are located, etc

Comments from Other Students in the Class (presentation reviews)

• FEA analysis was thorough and detailed

• Good speaking skills. Clear and concise.

• Explain why do you pick the certain points in the triaxial stress

• Maybe make equation look a little prettier

Schedule

• Describe upcoming milestone

  • Manufacture/assemble the final design of the prototype (2/13 - 2/25)

  • Quality control/test the final design (2/26- 3/2)

• Update Gantt chart.

Budget (list amount spent and amount remaining)

Team spent ($21) out of our $1000 budget limit

• Estimates :

  • PVC pipes ~$260

  • Pour foam ~$100

  • Stainless Steel wire rope and accessories ~$160

  • Fastening materials ~ $45

Progress on Report and Webpage

• In progress

  • Continue working on the final report (chapter 2,4, and appendix)

  • Making corrections to issues noted by TA and instructor
    

• Webpage has been updated

  • Week 7 progress report

  • Executive Summary needs to be completed and properly linked on home page

  • Descriptions need to be elaborated for final design tab

  • Organize webpage according to the class Webpage Guidelines